impact of global climate change on wetland systems · 2013. 10. 11. · poster abstract . abstracts...

ABSTRACTS - WETPOL 2013 - October 13-17, 2013 - Nantes - FRANCE

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Poster abstract


283

Synergistic approach in coupling a novel Biofilm BioReactor

(BBR) and MF/UF or NF membranes for WWT in presence of

pharmaceuticals (P.6)

M. Pontiéa, F. Chazarenc

b, M. Abassi

a, S.Ben Rejeb

a, O. Kama

b

aL’UNAM University, Angers University, GEPEA, UMR CNRS 6144, 2, Bd. Lavoisier,

49045 Angers, France ([email protected])

bL’UNAM, Ecole des Mines de Nantes, GEPEA, UMR CNRS 6144, 8 Bd. A. Kastler, 44000

Nantes, France ([email protected])

Mots-clés: biofilm bioreactor ; pharmaceuticals, ; biodegradability, MF/UF/NF

INTRODUCTION

We have recently designed a new tubular biofilm bioreactor (BBR), with a supported

biofilm dedicated to micropollutants biodegradation [Pontié et al. 2009]. It was elaborated in

one time to estimate the kinetics of biodegradation of inorganics/organics model

micropollutants (copper, pesticides and pharmaceuticals molecules and their metabolites).

The hydrodynamical defaults were investigated following the methodology of resident time

distribution (RTD). So we find the best hydrodynamical conditions to evitate short cut default

and now we engage more experiments to estimate both part of the mechanism of the

micropollutants biodegradation in natural and/or WW. RESULTS AND DISCUSSION Table n°1 : Turbidity, UV254 and para-nitrophénol (PNP) concentration in dam water (St Nicolas,

Angers, France) and treated with BBR alone,, UF alone, BBR+UF and NF

Figure n°1 : Flux permeate in UF (300 kDa, C/ZrO2) with and without the BBR

As illustrated in the Table n°1, from Turbidity measurements, BBR treatment alone is able

to eliminate a large part of the particules. But the water quality is not comparable with the

quality obtained using UF membrane treatment. Nonetheless membranes treatment alone are

not enough efficient due to the dramatic problem of fouling, as illustrated in the Figure n°1.


284

The integrated process coupling BBR and UF treatment show lots of synergies in terms of

water quality and limitation of membrane fouling. Furthermore the UF is not able to

eliminate micropollutants, the BRB yes by the biodegradation.

CONCLUSIONS

So the combination BRB+UF is the best solution in theory. In practice the efficiency of

the BBR+UF is sometimes not enough, depending on the micropollutants properties e.g. with

bad biodegradability of pollutants. In a near future the last solution should be to replace UF

by NF. As reported in the Table 1, the best water quality in term of micropollutants rejection

is obtained with the NF. So for recalcitrant micropollutants such as diclofénac (Voltaren®),

NF is required, alone or combined with a bioreactor, as recently reported [Chon 2012].

REFERENCES M. Pontié, F. De Nardi, J.B. Castaing, A. Massé, P. Jaouen, Biofilms et dépollution marine, SFGP09 à

Marseille, Poster communication, n°412.

Chon K. Bioresource Technology, 122 (2012) 181-188.


285

Removal processes of disinfection byproducts in subsurface-flow

constructed wetlands treating secondary effluent (PO.11)

Yi Chena,b

, Yue Wena, Qi Zhou

a, Jan Vymazal

b

a College of Environmental Science and Engineering, Tongji University, Shanghai 200092,

P.R. China ([email protected]) b Czech University of Life Sciences in Prague, Faculty of Environmental Sciences,

Department of Landscape Ecology, Czech Republic ([email protected])

INTRODUCTION

Chlorination of wastewater effluent has been reported to produce disinfection byproducts

(DBPs), some of which are carcinogenic and are consequently of health and regulatory

concern for downstream drinking water treatment plants. As CWs are widely used as tertiary

treatment systems to polish the wastewater treatment effluent, the fate of DBPs in CWs is of

great importance to the subsequent aquatic environment or the downstream drinking water

treatment plants. Rostad et al. (2000) reported that the surface-flow CWs (SF CWs) could

remove 78–97% of the THMs (with hydraulic retention times (HRTs) of 2–3 days) and

volatilization was considered to be the most likely route for THM removal. Compared with

the SF CWs, an increasing number of subsurface-flow CWs (SSF CWs) are used to further

treat the WWTP effluent due to the higher removal efficiency and smaller land requirement.

Unlike the SF CWs, volatilization of DBPs in the SSF CWs can be very low due to the

hindered water–air transfer via diffusion. On the other hand, reductive dehalogenation of

DBPs might be favored due to the negative ORP in SSF CWs. Therefore, DBP removal

efficiency and the removal mechanism might be different for SF CWs and SSF CWs.

However, whether or not DBPs can be eliminated using SSF CWs remains unclear.

METHODS

Six SSF CW microcosms (length: 0.3 m, width: 0.3 m, height: 0.5 m) were located in a

controlled greenhouse environment on Tongji University campus, Shanghai, China. These

were: an unplanted and non-biomass added unit (W0), an unplanted and biomass added unit

(W1, 100 g cattail litter), an unplanted and double biomass added unit (W2, 200 g cattail

litter), a planted and non-biomass added unit (W3, 22 plants m-2

), a densely planted and non-

biomass added unit (W4, 40 plants m-2

) and a planted and biomass added unit (W5, 22 plants

m-2

, 100 g cattail litter). All the microcosms were filled with gravel ( 8–13 mm, porosity =

0.4) and planted with cattail (Typha latifolia).

The experiment was carried out in January 2012. Every five days, 4000 μg of each DBP

was added to 80 L of secondary effluent in order to obtain a final concentration of 50 μg L-1

.

As the degradation of some DBPs (i.e. 1,1,1-TCP) could yield other DBPs (i.e. TCM), the

experiments were separated into two groups: one group had the THMs standard mix added

and the other had the EPA 551B Halogenated Volatiles mix added. During the experiment,

the wastewater in the CWs was gravity drained and re-filled every five days and the water

table was kept constant (45 cm) during each test period. During the experiment, the pH and

temperature in the wetland microcosms were 6.8–7.2 and 25 ± 1oC (controlled using an air

conditioner), respectively.

RESULTS AND DISCUSSION

Results showed that most of the 6 DBPs (except chloroform) were efficiently removed (>

90%) in six SSF CWs with hydraulic retention time of 5 d and there were no significant

differences between the systems. As shown in Figure 1, the degradation of DBPs in SSF CWs


286

followed first-order kinetics with half-lives of 1.0–770.2 h. As a primary DBP in wastewater

effluent, removal efficiencies for chloroform were higher in planted systems than in

unplanted ones and plant uptake accounted for more than 23.8% of the removal. Plant litter

greatly enhanced the removal of trihalomethanes (THMs) by supplying primary substrates

and reducing conditions, and the formation of dichloromethane supported the anaerobic

biodegradation of THMs via reductive dechlorination in SSF CWs. Trichloroacetonitrile was

completely removed within 10 h in each system and hydrolysis was considered to be the

dominant process as there was a rapid formation of the hydrolysis byproduct,

trichloroacetamide.

Fig. 1. Time courses for the removal of disinfection byproducts in SSFCW microcosms at 25

oC. (a)

Chloroform, TCM; (b) Bromodichloromethane, BDCM; (c) Dibromochoromethane, DBCM; (d)

Dibromoacetonitrile, DBAN; (e) Trichloroacetonitrile, TCAN; (f) Bromochloroacetonitrile, BCAN.

CONCLUSIONS

The fate of DBPs in SSF CWs and the effect of aquatic macrophytes on DBPs removal

were examined. Results showed that most of the DBPs were efficiently removed (> 90%

removal) in SSF CWs. The planted SSF CWs was more efficient for TCM removal than

unplanted units, and more than 23.8% of the TCM was removed by plant uptake, and

volatilization only accounted for 1.3-1.8 % in planted units. Anaerobic biodegradation of

THMs via reductive dechlorination was observed in SSF CWs with cattail litter.

0 20 40 60 80 100 120

0# W0: y=40.53exp(-0.025x), R2=0.95

1# W1: y=39.42exp(-0.094x), R2=0.98

2# W2: y=44.89exp(-0.105x), R2=0.99

3# W3: y=46.08exp(-0.023x), R2=0.98

4# W4: y=47.99exp(-0.021x), R2=0.98

5# W5: y=43.99exp(-0.119x), R2=0.98

Time (h)

c

DBCM

0# W0: y=56.95exp(-0.194x), R2=0.99

1# W1: y=56.98exp(-0.312x), R2=0.99

2# W2: y=46.85exp(-0.233x), R2=0.99

3# W3: y=45.78exp(-0.201x), R2=0.99

4# W4: y=44.90exp(-0.225x), R2=0.99

5# W5: y=47.37exp(-0.453x), R2=0.95

Time (h)

30252015105

f

BCAN

00 5 10 15 20 25 30

0

10

20

30

40

50

60

Ct (

g L

-1)

Time (h)

0# W0: y=50.88exp(-0.444x), R2=0.99

1# W1: y=48.30exp(-0.633x), R2=0.99

2# W2: y=47.16exp(-0.562x), R2=0.99

3# W3: y=43.93exp(-0.477x), R2=0.99

4# W4: y=41.98exp(-0.506x), R2=0.99

5# W5: y=46.19exp(-0.663x), R2=0.99

d

DBAN

0 20 40 60 80 100 120Time (h)

0# W0: y=45.21exp(-0.026x), R2=0.95

1# W1: y=40.25exp(-0.109x), R2=0.97

2# W2: y=43.62exp(-0.126x), R2=0.99

3# W3: y=45.11exp(-0.020x), R2=0.97

4# W4: y=52.43exp(-0.021x), R2=0.97

5# W5: y=40.02exp(-0.139x), R2=0.98

b

BDCM

0 5 10 15 20 25 30Time (h)

0# W0: y=49.55exp(-0.429x), R2=0.99

1# W1: y=47.39exp(-0.517x), R2=0.99

2# W2: y=45.84exp(-0.551x), R2=0.99

3# W3: y=47.69exp(-0.565x), R2=0.99

4# W4: y=48.33exp(-0.604x), R2=0.99

5# W5: y=48.32exp(-0.650x), R2=0.99

e

TCAN

0 20 40 60 80 100 120

0

10

20

30

40

50

60

Time (h)

TCM

W0: y=47.54exp(-0.001x)

W1: y=39.55exp(-0.017x)

W2: y=45.26exp(-0.029x)

W3: y=40.20exp(-0.003x)

W4: y=36.40exp(-0.006x)

W5: y=37.15exp(-0.021x)

Ct (

g L

-1)

a


287

Nutrient effects on Typha domingensis response to high metal

concentrations (PO.37)

M.M. Mufarrege, H.R. Hadad, G.A. Di Luca, G.C. Sánchez, M.A. Maine

Química Analítica, Facultad de Ingeniería Química, Universidad Nacional del Litoral.

Santiago del Estero 2829 (3000) Santa Fe, Argentina. Tel.: 54-0342-4571164 Int. 2515.

Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)

[email protected], [email protected]

INTRODUCTION

Typha domingensis was chosen for this study, since it was the dominant macrophyte in a

wetland constructed for the treatment of effluents of a metallurgic industry (Maine et al.,

2009), being Cr, Ni, Zn, N and P the contaminants found in the treated effluents. In order to

simulate extreme events, the concentrations studied were higher than the concentrations

commonly found in constructed wetlands. We hypothesized that nutrient enrichment

enhances the metal tolerance of macrophytes. Göthberg et al. (2004) reported that interactions

between metals and nutrients uptake are not only metal-specific but also species-specific. The

aim of this research was to study the nutrient influence on the tolerance, the removal

efficiency and the metal accumulation of T. domingensis exposed to high concentrations of

metals added together.

METHODS

Reactors containing two plants collected from a natural environment and 4 kg sediment

were disposed and acclimatized in a greenhouse. At the beginning of the experiment, the

plants were pruned and a combined metal and nutrient solution was added. The treatments

with the following water concentrations, arranged in triplicate, were:

Comb200: 200 mg L-1

Cr + 200 mg L-1

Ni + 200 mg L-1

Zn;

Comb600: 600 mg L-1

Cr + 600 mg L-1

Ni + 600 mg L-1

Zn;

Comb200+nut.: 200 mg L-1

Cr +200 mg L-1

Ni +200 mg L-1

Zn +50 mg L-1

P +50 mg L-1

N;

Comb600+nut.: 600 mg L-1

Cr +600 mg L-1

Ni +600 mg L-1

Zn +50 mg L-1

P +50 mg L-1

N;

Control 1: without metal or nutrient additions;

Control 2: 50 mg L-1

P +50 mg L-1

N, without metals.

The concentrations of metals in water, roots, rhizomes, leaves (aerial and submerged parts)

and sediment were measured at the beginning and at the end of the experiment. Relative

growth rates (RGR) were calculated based on plant height.


Table 1 shows metal percent removal from water at the end of the experiment. There were

not significant differences in removal percents between

treatments with and without nutrient addition. Nutrient

addition favours metal accumulation in tissues (Fig. 1).

Metal distribution in tissues at Comb200 treatments were

the expected, being metals mainly accumulated in roots.

At Comb600 treatments, not only the growth (Fig. 2)

but also the metal accumulation in tissues (Fig.1) was affected, being Ni and Zn

concentration remarkably high in aerial leaves, indicating important translocation.

Treatment

Removal

%Cr %Ni %Zn

Comb200 99.9 88.2 89.7

Comb200 + Nut 99.9 89.6 92.2

Comb600 94.4 59.6 57.5

Comb600 + Nut 93.4 58.2 5.8

mailto:[email protected]


288

Submerged leaves also presented high Ni and

Zn concentration, probably due to sorption by

direct contact with the solution. In the case of

Cr, the highest concentrations were found in

roots in all treatments. The treatments with

nutrient addition (including the control) showed

a significantly higher RGR than the obtained in

the treatments without nutrient addition

(Fig. 2). The treatments Comb600 showed a significantly lower RGR than that of Comb200.

Plant death was not observed. RGR were positive in all treatments, but they were

significantly lower that the obtained in the controls, demonstrating growth inhibition.

Despite the high metal concentrations in plant tissues, the sediment was the main metal

accumulation compartment due to its significantly higher mass than plant biomass.

CONCLUSIONS

Nutrient addition did not affected significantly metal removal from water. Despite plants

showed growth inhibition, nutrient addition favoured tolerance and metal accumulation in

tissues. Plant tissues accumulated efficiently the three metals. However, the sediment was the

compartment that showed the highest metal accumulation. These results could be applied to

enhance metal removal efficiency of constructed wetlands where nutrient enrichment could

be attained by treating sewage together with the industrial effluents.

ACKNOWLEDGEMENTS

The authors thank Consejo Nacional de Investigaciones Científicas y Técnicas

(CONICET), Universidad Nacional del Litoral (UNL)-CAI+D Project and Agencia de

Promoción Científica y Tecnológica for providing funds for this work.

REFERENCES Göthberg, A., Greger, M., Holm, K. and Bengtsson, B.E. (2004) Influence of nutrient levels on uptake and

effects of mercury, cadmium and lead in water spinach. J. Environ. Qual. 33:1247–1255.

Maine, M.A., Suñé, N., Hadad, H., Sánchez, G. and Bonetto, C. (2009) Influence of vegetation on the removal

of heavy metals and nutrients in a constructed wetland. J. Environ. Manag. 90:355-363.

Fig. 2. Relative growth rates (RGR) obtained at the end of the experiment.

Comb200

Comb200+Nut

Comb600

Comb600+Nut

Control 1

Control 2

0.000

0.005

0.010

0.015

0.020

0.025

Re

lative

gro

wth

ra

te (

cm

cm

-1 d

ay

-1)

Fig. 1. Metal concentrations determined at the end of the experiment in sediment and

tissues of T. domingensis.

Comb 200 Comb 200 + Nut Comb 600 Comb 600 + Nut0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

Zn

(m

g g

-1)

Aerial parts of leaves

Submerged parts of leaves

Roots

Rhizomes

Sediment

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

Ni (m

g g

-1)

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

Cr

(mg

g-1)


289

Nickel accumulation and its effects on Eichhornia crassipes (PO.38)

González C.I.a,c

, Maine M.A.a, Sanchez G.C.

a, Benavides P.

b

aQuímica Analítica, Facultad de Ingeniería Química, Universidad Nacional del Litoral.

Santiago del Estero 2829 (3000) Santa Fe, Argentina (([email protected])

cConsejo Nacional de Investigaciones Científicas y Técnicas (CONICET), ARGENTINA.

bDepartamento de Química Biológica, Junín 956, Ciudad de Buenos Aires, 1113,

ARGENTINA

INTRODUCTION

Aquatic plants play an important role in constructed wetlands systems for the treatment of

wastewaters containing metals. Nickel is an essential element for plant growth and

development (Liu, 2001). However, at higher concentrations nickel is a toxic pollutant,

inducing lipid peroxidation and oxidative stress. These physiological and biochemical

damages can result in a dramatic reduction of the growth and productivity of plants,

eventually causing death.

The main aim of this work was to study the effect of nickel accumulation in Eichhornia

crassipes. The responses of physiological parameters, oxidative damage and changes in

antioxidant enzyme activities were evaluated in roots and aerial parts.

METHODS

Macrophytes were collected from natural wetlands and acclimated for one week in the

laboratory (under controlled conditions of temperature, humidity and light) using

dechlorinated water as culture medium. Two litres of water and one plant were added in

experimental reactors. Nickel was added to obtain concentrations of 1, 2, 3 and 4 mg/L. The

study was conducted over 3 days, sampling at periods of 24, 48 and 72 h. The experiments

were performed in triplicate with a control in the absence of Ni.

The following analytical determinations were performed:

+ Measurement of concentration of chlorophyll a, b and α-β carotenoids: Wellburn (1994).

+ Determination of lipid peroxidation: Heath and Packer (1968).

+ Determination of enzymatic activity of catalase: Maehly and Chance (1954) (modified).

+ Determination of enzymatic activity of guaiacol peroxidase: Bergmeyer (1983).

+ Determination of nickel in tissues: atomic absorption spectrophotometry.


According to Fig. 1, the accumulation of nickel in roots and aerial parts increased

depending on concentration and exposure. Higher levels of nickel were recorded in roots and

lesser amounts were translocated to aerial parts.

Nickel produced a significant increase of chlorophyll a and b, for concentrations of 3 and

4 mg/L in the first 24 h of contact. At 48 h an increase in the exposures of 1 and 2 mg/L was

observed, but a decrease at all exposures was detected at 72 h. This could be an indication of

growth inhibition. However, there were no significant differences among the chlorophyll

concentrations between the different exposures and the control.

Compared to the control, malondialdehyde (MDA), a marker of lipid peroxidation,

increased significantly in the exposure of 4mg/L at 24 and 48 h in aerial parts. In roots, a

significant increase of 19.2 % and 26.4 % in malondialdehyde level was found at 3 and 4

mg/L, respectively, for the period of 72 h.

A significant increase of catalase activity in the aerial parts was observed in the first 24 h,

with a maximum of 44.40 (nmol min-1

mg-1

prot) at the concentration of 3 mg/L. After 24 h


290

the activity decreased significantly with an increasing exposure time, reaching a value below

those of the control. Regarding roots, no significant differences among concentrations and

exposure times were observed in the catalase enzyme activity. The guaiacol peroxidase

activity increased significantly in all treatments performed both in aerial parts and in roots.

This may indicate that the guaiacol peroxidise enzyme plays an important role in antioxidant

defence.

Fig. 1. Accumulation of Ni (mg/g DW) in the aerial parts (a) and roots (b) of E. crassipes at different

concentrations and exposure periods.

CONCLUSIONS

A short exposure to the nickel concentrations assayed caused physiological changes that

implied an increase in the photosynthetic activity. These changes would provide the energy

needed to sustain the increased activities of antioxidant enzymes. Plants tolerated the nickel

exposure and a similar response could be expected in a constructed wetland for effluent

treatment.

ACNOWLEDGEMENTS

Financial support for this research was provided by the Consejo Nacional de

Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional del Litoral (UNL)-

CAI+D Project and Agencia de Promoción Científica y Tecnológica.

REFERENCES Bergmeyer H.U.(1983) Methods of Enzymatic Analysis, vol. I. VCH Weinheim, Germany.

Heath, R.L., Packer, L. (1968)Photoperoxidation in isolated chloroplasts. I. Kinetics and stoichiometry of fatty

acid peroxidation. Archives in Biochemistry and Biophysics125: 189-198.

Liu G.D. (2001) A New Essential Mineral Element-Nickel. Plant Nutrition and Fertilizer Science 7(1):101-103.

Maehly, A.C., Chance, B.(1954)The assay of catalases and peroxidases. Methods Biochem.Anal.1:357-424.

Wellburn, A.R. (1994)The spectral determination of chlorophyll a and b, as well as total carotenoids, using

various solvents with spectrophotometers of different resolution. J. Plant Physiol. 144:307-313.


291

Investigation of phenol and m-cresol biodegradation in horizontal

subsurface flow Constructed Wetlands (PO.165)

Alexandros Stefanakisa, Eva Seeger

a, Thomas Hübschmann

a, Susann Müller

a,

Anja Sinkeb, Martin Thullner

a,

a Department of Environmental Microbiology, Helmholtz Centre for Environmental Research

– UFZ, Permoserstraße 15, 04318 Leipzig, GERMANY ([email protected]) b

BP International Limited, Sunbury on Thames, Middlesex, TW16 7BP, UK.

INTRODUCTION

Constructed Wetlands (CWs) have been proven to be effective in the treatment of

groundwater contaminated with organic pollutants like benzene and MTBE, promoting their

removal mainly via aerobic biodegradation (Seeger et al., 2011). In contrast, CW removal

processes for phenols in have not been fully understood, yet. The aim of this project is to

investigate the fate of two phenolic compounds (phenol and m-cresol) in pilot-scale CWs, to

estimate the role of biodegradation and other treatment processes for phenol removal, and to

determine the impact of phenol on the removal of other contaminants (benzene and MTBE).

METHODS

Three pilot-scale horizontal subsurface flow CWs (steel basins; L:W:D = 5.9:1.1:1.2 m)

are used in the experimental facility located in Leuna, Germany. Two beds (A, C) are planted

with common reeds (Phragmites australis) and one (B) is left unplanted. All units are fed

with contaminated groundwater (pumped from the local aquifer and containing benzene and

MTBE) at an inflow rate of 11 L/h and a hydraulic residence time of one week. A solution of

phenol and m-cresol is injected to the contaminated groundwater loaded to the units A and B

(inflow concentrations: 10 and 2 mg/L for phenol and m-cresol, respectively). The first

experimental period lasted for a 10 weeks period (August-October 2012). The ongoing

operation and monitoring covers the entire growth season (April-October 2013).

Samples are taken from the influent and effluent points of each bed at a bi-weekly scheme.

Emphasis is given in the pollutant spatial distribution, in order to obtain a better insight into

the removal processes. Thus, samples are taken once a month from three different points

along the wetland length (0.5, 1.9, 4.1 m) and three depths (0-5, 30, 80 cm). All samples are

analysed for the determination of phenol and m-cresol concentrations. Microbial community

patterns are observed via flow cytometry.


Results from 2012 and first results from 2013 (Figure 1) show an almost complete

removal of phenolic compounds in the effluent of the planted unit A after the first 20

operational days (effluent values close to 0.0), while the unplanted bed has a slightly reduced

performance. Spatial analysis shows lower concentration values in all sampling points within

the planted bed compared to the unplanted one. Concentrations in points closer to the bottom

are also higher in the unplanted bed, indicating the lack of oxygen in the deeper parts and the

positive effect of plant presence. No phenolic compounds were detected in the control unit C.

First analyses of the microbial community using flow cytometry (Figure 2) show initially

similar patterns for the effluent of all units, while during the experiment the units receiving

phenol/m-cresol exhibit an increasing shift of the community.


292

Fig. 1. Phenol and m-cresol influent and effluent concentration variations at various sampling campaigns

in 2013.

Fig. 2. Microbial community patterns obtained on 13/5/2013 one month after beginning of phenol/m-

cresol injection.

CONCLUSIONS

The results obtained so far suggest that the investigated horizontal subsurface flow CWs

are an appropriate technology for the removal of phenolic compounds from contaminated

groundwater. Biodegradation of pollutants seems to be the dominant removal mechanism,

while the removal is enhanced by the presence of plants and the respective plant root activity.

Vertical concentration profiles in the CW show that in deeper parts the lack of oxygen

reduces but does not stop the contaminant removal, especially in the unplanted bed. This

indicates that oxygen input via the CW surface affects the aerobic removal rate but also anaerobic

removal is taking place. Flow cytometry analysis implies a shift in the microbial community in the

two beds which were fed with phenol/m-cresol suggesting an adaptation of the community to the

additional contaminants. The continuation of the experiment during the entire growth season of this

year and respective further analyses will provide significant data in order to determine the factors

affecting these alterations.

ACKNOWLEDGEMENTS

This study is funded by BP International. Further funding was provided by the Helmholtz

Centre for Environmental Research – UFZ in the scope of the SAFIRA II Research

Programme: Revitalization of Contaminated Land and Groundwater at Megasites, project

“Compartment Transfer.” The technical support was provided by the UFZ Departments

Groundwater Remediation and Isotope Biogeochemistry.

REFERENCES Seeger, E., Kuschk, P., Fazekas, H., Grathwohl, P., Kästner, M. (2011) Bioremediation of benzene-, MTBE- and

ammonia-contaminated groundwater with pilot-scale constructed wetlands. Environ. Poll. 159(12):3769-3776.


293

Factors Affecting Runoff Pollutants Removal in Soil-Plant

Systems (PO.30)

HD Zhoua

aDepartment of Water Environment, China Institute of Water Resources and Hydro-power

Research, Beijing, 100038, China ([email protected])

INTRODUCTION

The soil-plant system is considered to be low-cost and high-efficiency technology on

pollutant removal. Only a few reports on runoff pollutant removal efficiency through soil-

plant systems are available and little is known about the effects of multi-factor experiment on

runoff pollutant removal in China. Thus, the effects of vegetation type, pollutant

concentration, flow velocity and slope on pollutant removal efficiency will be investigated in

the study. The control system and soil-plant system (including “soil-alfalfa” and “soil-tall

fescue”) were constructed to study the effects of single-factor experiment and multi-factor

experiment on runoff pollutant removal. Suspended solid (SS), particulate phosphorus (PP),

total dissolved phosphorus (TDP), ammonium (NH4+-N), and nitrate (NO3

--N) are pollutants

of great concern.

METHODS

A set of soil plant systems consisting of stainless steel plating bath and bracket are

constructed (Fig.1). The main composition of soil particles are listed in Table 1.

Fig. 1. Structure of soil plant system(mm)

Table1. Main physical and chemical properties of the tested soil

TOC total N total P pH mechanical composition %

g Kg-1

g Kg-1

g Kg-1

Sand Particle Powder Particle Clay particle

5.64 0.191 0.243 7.60 70.96 26.00 3.04

The runoff samples of the inflow and outflow were collected at 2m, 4m and 6m every

10～15 min during the experiment process.


1. Single-factor experiment

Results of single-factor experiment show the removal efficiency on pollutants were

obviously better by soil-plant system than these by control system (Table 2), the mean

removal efficiency on SS, NO3--N, NH4

+-N, TDP and PP increase 244%, 100%, 274%, 9%

and 488%, respectively. The removal efficiency on NO3--N, NH4

+-N and TDP were obviously

better by “soil-tall fescue” system than “soil-alfalfa”system (P <0.05) under the medium

concentration condition.


294

Table 2. Results of single-factor experiment

Group Reduction of concentration [%]

SS PP NO3--N NH4

+-N TDP

C 25.49±17.97 13.07±5.71 14.97±7.62 17.65±10.38 25.35±8.86

A1 87.50±6.25 81.41±2.46 31.27±3.46 63.44±4.93 28.16±3.32

A2 88.20±5.25 77.66±1.79 33.20±4.64 58.32±4.12 26.30±2.22

A3 84.13±7.27 70.71±3.53 13.03±2.90 34.33±9.29 25.12±1.55

B1 88.10±8.25 72.32±5.23 28.54±3.85 59.20±6.21 27.15±6.05

B2 74.23±6.54 67.89±6.69 19.78±2.31 42.30±3.90 20.20±5.23

B3 75.44±10.96 70.06±2.76 16.68±1.94 22.75±3.99 22.51±1.71

Vegetation: C: Control system; A1-A3: soil-tall fescue system; B1-B3: soil-alfalfa system

2.Orthogonal experiment Table 3. Results of orthogonal experiment

Factor Vegetation Cin [mg L-1] Flux Slope Test indexes

No. level Mean removal rates [%] (n=2)

SS PP CODMn NO3--N NH4+-N TDP

1 C L L 3% 61.57 71.96 69.48 -5.12 -19.05 7.78

2 C M M 6% 21.63 75.49 38.51 -2.70 7.78 9.52

3 C H H 10% -82.56 -89.41 3.11 -0.97 4.24 15.30

4 B L M 10% 90.56 91.50 52.30 -0.27 20.41 21.50

5 B M H 3% 58.45 73.34 46.98 7.65 25.79 16.96

6 B H L 6% 74.79 84.48 53.73 7.49 34.54 37.36

7 A L H 6% 79.62 94.37 71.50 13.25 47.50 42.63

8 A M L 10% 84.80 93.72 52.14 29.81 46.25 42.94

9 A H M 3% 65.13 54.80 58.21 13.83 43.15 47.93

Vegetation: C: Control system; A: soil-tall fescue system; B: soil-alfalfa system; Cin: L:low, M: medium,

H:high; Flow velocity: L:low, M: medium, H:high

The pollutants purifying effect were obviously better by “soil-alfalfa” system and “soil-tall

fescue” system than control system (Table 3). There are similar removal characters between

particulate pollutants such as SS and PP. Removal efficiency of CODMn is also similar to

particulate pollutants. Removal efficiency of pollutants decreased with inflow concentration,

flow velocity and slope increasing. The most obvious factor is vegetation type for the

dissolved NO3--N, NH4

+-N and TDP removal. Removal efficiency of NO3

--N, NH4

+-N and

TDP were obviously better by “soil-tall fescue” system than “soil-alfalfa”system, which are

different from particulate pollutants.

CONCLUSIONS

Both results of single-factor experiment and orthogonal experiment show the removal

efficiency on pollutants were obviously better by soil-plant system than these by control

system. Results of orthogonal experiment show vegetation type, inflow concentration, flow

velocity and slope are the primary factors to affect the removal efficiency on SS, PP and

NH4+-N. Removal efficiency of pollutants decreased with inflow concentration, flow velocity

and slope increasing. Removal efficiency on the dissolved pollutants was obviously better by

“soil-tall fescue” system than “soil-alfalfa” system.

ACKNOWLEDGEMENTS

This study was supported by China IWHR Program (HJ1339), National Water Program

(2012ZX07203-006), and National Natural Science Foundation, China (21247007).


295

Arsenic Removal Processes for Groundwater in a Treatment

Wetland (PO.162)

M.T. Alarcón-Herreraa, M.C. Valles-Aragón

a Center for Advanced Materials Research. CIMAV. Miguel de Cervantes 120., Chihuahua

C.P. 31109, MEXICO. [email protected]

INTRODUCTION

Arsenic pollution in groundwater is a worldwide issue due to its toxicity and chronic

effects on human health. This problem has generated an increasing interest in the use of

different treatment technologies to remove arsenic from contaminated groundwater sources.

Treatment wetlands are a cost-effective natural system successfully used for removing

different organic and inorganic pollutants and have shown high capability for removing

arsenic. In this study, the main contaminant removal processes occurring in subsurface-flow

treatment wetlands treating groundwater were reviewed. The redox conditions, pH and

temperature, prevailing in the treatment wetlands were analyzed and linked to elucidate the

possible arsenic removal processes.

METHODS

The study was conducted with three constructed wetlands prototypes. Two planted (HA

and HB) with Eleocharis macrostachya and Schoenoplectus americanus respectively; other

one (HC) remained unplanted as a control (Figure 1). The system was fed with synthetic

water, prepared with groundwater added with Sodium Arsenite (NaAsO2) in order to reach

As values of 90 ± 15µg/L. Redox potential (Eh): was continuously monitored by a digital

equipment (Hach, PC SC and RC model: Sc 1000), with a range of 0 ± 2000mV and ±20mV

of accuracy. pH was measured, three times per week in every sampling well. Water

temperature was automatically monitored every hour using a conductivity data logger

(HOBO U24-00) in a range of -2 up to 36ºC and 0.1 ºC of accuracy. Environmental

temperature was monitored using temperature sensors (HOBO, Light Logger UA-002-64) in

a temperature range of -20 up to 70 ºC and ± 0.54°C of accuracy.

Arsenic determinations

Samples were taken from the water inflow and outflow every week. Arsenic

determinations were carried out using an atomic absorption spectrophotometer with hydride

generator GBC Avanta Sigma equipment. Duplicate samples, certified standards (traceable at

National Institute of Standards and Technology, NIST), and blanks were analyzed. Arsenic

recovery from analyzed controls was 96% ± 3% for all samples. Arsenic quantification limit

was 5µg/L.


Results shown that oxidized conditions from 87 to 516mV were presented during 84 and

90% of the days in the hot and warm seasons respectively; while reduced conditions where

reported the rest of the time (up to -539mV). On the cold season, only oxidized conditions

were observed. Eh values fluctuated as a consequence of weather conditions (the lower the

temperature, the higher the Eh). pH values were lower than 8, which indicate that HAsO42-

was the main As specie. Under this circumstances it was assumed, that As can be retained by

precipitation/absorption onto Fe3+

and Mn5+

oxyhidroxides (at pH≥6.5 and Eh>0), since high

pH and oxidize conditions enhance the oxides-arsenic affinity (Marchand et al., 2010).


296

During the experiment, pH values in every wetland sections, ranged from 7.0 to 8.0 on HA

and HB. Higher pH values (8.0 to 8.5) were registered for HC. Other authors reported the

same tendency with pH values in a range from 7.2 to 8.1 in planted wetlands, whereas

unplanted wetlands range was from 8.1 to 8.5 (Zurita et al., 2012).

Arsenic retention was around 87% in the planted system, compared to 46% in the

unplanted. According to these results, root activity is highly involved on As immobilization

on planted wetlands (Rahaman et al., 2011). The lower As retention in the unplanted

prototype, was attributed to alkaline pH prevailing in the mesocosms (pH>8.5). At this

conditions As desorption was theoretically due to the negative charge on the mineral surface

(Frohone et al., 2011).

Fig. 1.-Diagram of experimental design: a) HA and HB: prototypes with plants, HC: no plants. b)

monitoring and sampling wells.

CONCLUSIONS

The increased capacity of the soil to retain As in the mesocosms prototypes was attributed

to the plants. Rhizosphere oxygenation through plants promoted oxidized conditions in the

mesocosms most of the operational time. Under this conditions, the arsenic removal as As+5

was propitiated by precipitation and its adsorption onto oxyhidroxides (Fe+3

and Mn+5

)

present in the soil.

ACKNOWLEDGEMENTS

This research has been supported by the Spanish Agency for International Development

Cooperation (AECID) through the projects 10-CAP1-0631 and 11-CAP2-1583. This study

has also been co-funded by the Spanish Ministry of Economy and Competitiveness and the

European Union through the European Regional Development Fund.

REFERENCES Frohne, T., Rinklebe, J., Diaz, R., Du Laing, G. (2011). Controlled variation of redox conditions in a floodplain

soil: Impact on metal mobilization and biomethylation of arsenic and antimony. Geoderma, 160 pp. 414 - 424.

Marchand, L., Mench, M., Jacob, D., Otte, M. (2010). Metal and metalloid removal in constructed wetlands,

with emphasis on the importance of plants and standardized measurements: A review. Environmental Pollution,

158 pp.3447-3461.

Rahman, K., Wiessner, A., Kuschk, P., Afferden, M., Mattuschc, J., Müllera, R. (2011). Fate and distribution of

arsenic in laboratory-scale subsurface horizontal-flow constructed wetlands treating an artificial wastewater.

Ecological Engineering. 37 pp. 1214–1224.

Zurita, F., Del Toro-Sánchez, C., Gutierrez-Lomelí, M., Rodriguez-Sahagún, A., Castellanos-Hernandez, O.,

Ramírez-Martínez, G., White, J. (2012). Preliminary study on the potential of arsenic removal by subsurface

flow constructed mesocosms. Ecological Engineering, 47 pp. 101-104.

(a) (b)


297

Abundance and proportion dynamics of antibiotic resistance

genes and their relationships with system treatment efficiency in a

newly established horizontal subsurface flow constructed wetland (PO.15)

Kertu Tiirik, Hiie Nõlvak, Marika Truu, Kristjan Oopkaup, Teele Sildvee, Ants

Kaasik, Ülo Mander, Jaak Truu

Institute of Ecology and Earth Sciences, Faculty of Science and Technology, University of

Tartu, 46 Vanemuise St, 51014, Tartu, Estonia.

([email protected]); http://dx.doi.org/10.1016/j.scitotenv.2013.05.052

INTRODUCTION

The occurrence and spread of antibiotic resistant bacteria in the environment is a well-

recognized concern to the extent where, besides antibiotic residues, the antibiotic resistance

genes (ARGs) are being considered as pollutants themselves (Martínez, 2009). Municipal

wastewater treatment is one of the pathways by which antibiotic resistance genes from

anthropogenic sources are introduced into natural ecosystems (Novo and Manaia, 2010). This

study examined the abundance and proportion dynamics of seven antibiotic resistance genes

(tetA, tetB, tetM, ermB, sul1, ampC, qnrS) on the filter material and in the influent and

effluent of horizontal subsurface flow mesocosms (HSSF MCs) of a newly established hybrid

constructed wetland (CW) treating municipal wastewater.

METHODS

Site description and sampling

150-day experiment was conducted from June to November 2009 in Nõo village, Estonia,

in the hybrid CW system fed with raw wastewater pumped from the inlet of the activated

sludge treatment plant. Sampling began after 26 days of regular operation of the CW system

and samples were collected five times during the five-month trial period.

DNA extraction

Collected wetland media was crushed and DNA was extracted from the crushed material.

Wastewater samples were centrifuged and DNA from the pellet was extracted.

Preparation of standards for qPCR calibration

Target gene fragments were PCR-amplified from environmental samples using the

respective primers and PCR-products were cloned into vector plasmid. Plasmid-DNA was

extracted and controlled with nucleotide sequencing. Standard DNA stock solutions of 109

copies of plasmid/μl were prepared and serial dilutions ranging from 108 to 25 target gene

copies were used for creating standard curves.

Quantitative PCR conditions and analyses

All qPCR reactions from samples and standards were run in triplicate. For qPCR data

analyses Rotor-Gene Series software and the LinRegPCR program in combination with a

three-step outlier removal process were used (Nõlvak et al., 2012).

Statistical analysis

The differences in amplification efficiencies of the targeted ARGs and 16S rRNA in the

HSSF MC environments were estimated using t-test. Spearman’s rank correlation coefficient

was used to evaluate the extent to which water quality parameters and wastewater

purification efficiencies correlated with target gene concentrations and relative abundances.


298


All seven targeted ARGs were detectable in the influent, wetland media biofilm (WMB),

and effluent of the HSSF MCs, with the tetA, sul1, and qnrS genes being the most abundant

in the mesocosm effluents. After initial fluctuation in the microbial community, target gene

abundances and proportions stabilized in the WMB. The abundance of 16S rRNA and ARGs,

and the proportion of ARGs in the microbial community, were reduced during the wastewater

treatment by the constructed wetland. The concentration of ARGs in the system effluent was

similar to conventional wastewater treatment facilities; however, the mesocosms reduced

sulfonamide resistance encoding sul1 concentrations more effectively than some traditional

wastewater treatment options. The concentrations of ARGs in the mesocosms WMB and in

effluent were affected by system operation parameters, especially time and temperature. The

results also revealed that efficient removal of NO2-N promoted the abundance of ARGs in the

HSSF MCs effluent and the extensive removal of NH4-N and organic matter lowered the

amount of ARGs in CWs effluent. Data analysis showed strong correlation between ARG

abundance dynamics in the influent and effluent for the tetA, tetB, and sul1 genes, and for the

effluent and WMB for tetA, tetB, and qnrS genes; a weak correlation between tetM

abundance dynamics in the influent and WMB was also recorded. No such relationships were

found for ermB and ampC genes. Significant correlations between the abundance of

individual ARGs in the mesocosms influent, effluent, and WMB indicate that the ARGs-

carrying microbes entering the system interact differently with microbial communities

already present in the WMB of mesocosms. The nature of these different mechanisms

remains to be established.

CONCLUSIONS

All targeted ARGs were detectable in the tested mesocosm environments. The abundance

of 16S rRNA and ARGs, and the proportions of ARGs in the microbial community, were

reduced during the wastewater treatment process. ARG concentrations in HSSF MCs WMB

and in the effluent were affected by system operation parameters. A relationship between

ARG abundance and the removal efficiencies of nitrogen and organic matter in the system

was found. ARG-carrying microbes entering the system interact differently with the

microbial community already present in the mesocosm. Current findings contribute

considerably to the knowledge of antibiotic resistance behavior in CWs and can help

improving treatment systems design and optimization.

ACKNOWLEDGEMENTS

This study was supported by the Ministry of Education and Research of the Republic of

Estonia (grant IUT2-16), state program “Aid for research and development in environmental

technology,” grant 3.2.0801.11–0026, and by the European Regional Development Fund

through ENVIRON (Centre of Excellence in Environmental Adaptation).

REFERENCES Martínez, J.L. (2009) Environmental pollution by antibiotics and by antibiotic resistance determinants. Environ.

Pollut. 157:2893-2902.

Novo, A. and Manaia, C.M. (2010) Factors influencing antibiotic resistance burden in municipal wastewater

treatment plants. Appl. Microbiol. Biotechnol. 87:1157-1166.

Nõlvak, H., Truu, M., Truu, J. (2012) Evaluation of quantitative real-time PCR workflow modifications on 16S

rRNA and tetA gene quantification in environmental samples. Sci. Total Environ. 426:351-358.


299

Removal Indicator Microorganisms in three Subsurface

Horizontal Flow Constructed Wetland Treating Domestic

Wastewater in Interior Region of Portugal (PO.27)

M.C. Mesquitaa, F.A Carreiro

b, A. Albuquerque

c, L. Amaral

d, R. Nogueira

e

a,bHigh School of Agriculture, Polytechnic Institute of Castelo Branco, Quinta da Senhora de

Mércules, Apartado 119, 6001-909 Castelo Branco, Portugal ([email protected] ,

presenting author)

cDepartment of Civil Engineering and Architecture, University of Beira Interior, Bloco II das

Engenharias, Calcada do Lameiro, 6201-001 Covilha, Portugal.( [email protected])

dDepartment of Sciences and Environmental Engineering, Faculty of Sciences and

Technology, New University of Lisbon, 2829-516 Caparica, Portugal. ([email protected])

e Institute for Sanitary Engineering and Waste Management Welfengarten 1 30167 Hannover,

Germany. (E-mail: [email protected])

INTRODUCTION

Reuse of wastewaters plays an important role in the management of water resources,

which particularly relevant in the Mediterranean Region where demand increases while

quality decreases. Use in agriculture can be beneficial in terms of productivity while it

contributes to recycling of nutrients and water. Wastewater reclamation leading to water-

reuse opportunities has gained considerable importance over the last two decades, particularly

in countries like Portugal, where water is a scarce resource, despite currently very little

sewage effluent is reclaimed and reused. Typically, treated effluent is discharged into rivers,

However, a major issue and risk to human health with municipal effluent reuse is the

potential of sewage-borne pathogens. Constructed wetlands (CW), an effective small-scale

wastewater treatment system with low energy and maintenance requirements and operational

costs, appear to be effective on removals of pathogenic organisms from wastewater (Puigagut

et al., 2007). Wetland systems are known to act as biofilters through a complex of physical,

chemical and biological factors which can contribute for reduction the number of bacteria

(Arias et al., 2003; Vymazal, 2009). The use of macrophyte systems in the treatment of

domestic wastewaters has increased during the past decade at Portugal and the data on

removal of microbial indicators by these systems are limited. Abundant sunlight at summer

period and average temperature above 20 ºC, make constructed wetland technology to be

potential appropriate solution for microorganisms removal from domestic wastewater in

Interior Central Region of Portugal, known for their very high rates of evaporation and water

scarcity at summer period. In order to increase the knowledge of faecal indicator organism

removal by subsurface horizontal constructed wetland system planted with Phragmites

australis, studies were carried out at three locations of Interior Central Region of Portugal.

The studies were carried out for three months in summer season.

METHODS

This study was carried on in three gravel-based horizontal subsurface flow CW, located at

Aranhas, Capinha and Janeiro de Cima (Interior Central Region of Portugal), between May

and August 2008, in order to evaluate their efficiency in the removal of total coliforms (TC),

faecal coliforms (FC) and faecal streptococci (FS) during the passage of settled domestic

sewage through the wetlands system. The summer period was chosen since is the season that

may present more problems for CW performance due to high evaporation rates and high


300

variation of incoming loads. The system of Aranhas include a single bed (642 m2) and a

specific surface area (SSA) of 1.5 m2/p.e., whilst Capinha and Janeiro have 2 beds in parallel

with areas of 1 546 m2 (SSA = 3 m2/p.e) and 1 060 m2 (SSA = 3 m

2/p.e), respectively. All

the beds run as secondary treatment, were colonised with Phragmites australis and the water

level was 0.5 m. The primary treatment consists of a septic tank (Aranhas) or an Imhoff tank

(Capinha and Janeiro). The influent flow-rate was measured daily. Biweekly water samples

were collected at the inflow and outflow of each CW system (32 samples). The mean flow-

rate was 49, 45 and 58 m3/d for Aranhas, Capinha and Janeiro, respectively, which

corresponds to hydraulic loading rates (HLR) of 7.6, 3 and 5.5 cm/d, respectively. Water

samples were collected in presterilised polypropylene bottles and analysed within 6 hours in

the laboratory. Bacterial concentrations were determined by using the multiple tube

fermentation technique, based on Standard Methods (APHA-AWWA-WPCF, 1995). The

measurement of TC, FC and FS is expressed as the number of colony-forming units (CFU’s)

per 100 mL of water.


Indicator bacteria concentrations in inflow to CWs were of the order of 106/100 mL. The

average percentage TC removal was 93% (Aranhas), 84 % (Capinha) and 53% (Janeiro de

Cima), while the average percentage CF removal were 96% (Aranhas), 85 % (Capinha) and

75% (Janeiro de Cima). The removal of FS is usually in the range between 65 and 85%.

Removal efficiencies were observed to be consistent with values reported in the literature

and can be attributed to the metabolic activity at root biomass that are supposed to provide an

effective substrate to microbial attachment surface and filtering capacity and probably

increases in the populations of predator microbes resulting from optimal temperatures at

warmer months of the year.

Indicator bacteria in the influent to CWs were of the order of 106/100 mL. In all systems

the concentration of TC, FC and FS decreased from the influent to the effluent and the

systems removed 1 to 2 logarithmic units. For TC and FC the outflow concentrations are

usually in the range of 102 to 10

5CFU/ 100 ml while for FS the range is between 10

2 and

104CFU/ 100 ml. Despite high removal efficiencies, faecal-coliform concentrations in the

final effluent are often higher than 100CFU/100mL, imperative value laid down in the

Portugal Law for the quality of irrigation water.

CONCLUSIONS

The use of secondary-treated for irrigation is regarded as a health risk if it has not been

disinfected to remove potential human pathogenic microorganisms, and disinfection comes at

a cost. The data show that the relative performance of the beds was similar, and on average,

all systems study were efficient in removing faecal indicator bacteria studies. However,

although there was a decrease in the abundance of total bacteria with treatment, generally

faecal coliform organism were not reduce down to the limit of 102CFU/100 mL, standards

pertaining to the concentration of sanitary indicator bacteria in irrigation water at Portugal.

REFERENCES Arias, C.A., Cabello, A., Brix, H., Johansen, N.H. (2003) Removal of indicator bacteria from municipal

wastewater in an experimental two-stage vertical flow constructed wetland system. Water Sci.Technol. 48

(5):35–42.

Puigagut J, Villaseñor J, Salas JJ, Bécares E, García J. (2007) Subsurface-flow constructed wetlands in Spain for

the sanitation of small communities: a comparative study. Ecol Eng, 30:312–319.

Vymazal, J. (2009) The use constructed wetlands with horizontal sub-surface flow for various types of

wastewater. Ecological Engineering 35:1-17.


301

Varied redox potentials contribute to nitrogen removal (PO.109)

Yuansheng PEIa, Ziyuan WANG

a

aMOE Key Laboratory of Water and Sediment Sciences, Beijing Normal University. No.19,

Xinjiekouwai Street, Beijing 100875, CHINA ([email protected]; [email protected])

INTRODUCTION

Redox potential (ORP) is considered as a broad indicator to the microbial diversity and

activity, and can be used to optimize growth of functional bacteria and to offer design and

operational methodologies of constructed wetlands (CWs) (Mermillod-Blondin et al., 2005).

Alternation of ORPs in CWs is essential to oxidation and reduction of nitrogen compounds;

also CWs designed with appropriate structure can improve nitrogen removal (Bettez and

Groffman, 2012). In this work, a three-stage CW with ORPs gradient was established to

remove nitrogen and molecular microbiological methods were employed to illustrate the

mechanism of nitrogen removal.

METHODS

The CWs were comprised of five columns with different heights (Fig. 1a). Columns 1, 3

and 5 were downside columns, while columns 2 and 4 were upside columns. Stages 1 and 2

were composed of an anoxic/oxic (A/O) zone and an anaerobic column. Seven sample sites

were arranged. The influent flow rate was kept at 0.12 L/h. Hydraulic retention time was 8 h.

Fig 1. The simulation system with varied ORPs (a) and the cluster analysis and DGGE pattern of 16S

rRNA fragments for each site in the system (b).

Water samples were analyzed according to the standard method. Biofilm was collected in

the CWs, where Genomic DNA was extracted by using a FastDNA SPIN kit for soil. The 16S

rDNA genes of bacteria were amplified using the GC-clamped primer sets: 338f-907r. DGGE

analysis was conducted using the D-code system (Bio-Rad, CA, USA). The sequences

determined in this study were deposited into the GenBank database (JN936915 to JN936921).

The abundance of AOB and NOB as percentage of all bacteria was calculated.


Microbial community

The richness and structural diversity increased in A/O zones (Fig. 1b). The major

populations were heterotrophic bacteria. Both AOB and NOB populations increased and

AOB were more abundant than NOB (Table 1). While the β-proteobacteria AOB were the

main species, NOB was principally found at site 1, 2, 4 and 7. The existences of AOB and

NOB were closely related to ORPs at each site. In A/O zones, the AOB and NOB thrived

with denitrifying bacteria and made contribution to nitrogen removal.


302

Table 1 Population of AOB and NOB in the constructed riparian system by FISH analysis (%).

Population Site 1 Site 2 Site 3 Site 4 Site 5 Site 6 Site 7

AOB 8.42 6.72 0.87 6.23 6.01 2.01 4.20

NOB 3.32 3.10 0.81 2.26 1.45 0.92 1.68

Nitrogen removal efficiency

The system was under different oxic or anoxic conditions. The variation of ORPs provided

different environment for nitrogen removal bacteria. The average TN removal ranged 75-

93%, and the nutrient removal rates were impacted by ammonium loading significantly (Fig.

2a).

0 20 40 60 80 100

0

4

8

12

16

20

24

NH4-N

NO3-N

NO2-N

N s

pec

ies

con

c. (

mg

/L)

Time (d)

0

20

40

60

80

100

TN removal rates T

N r

emo

va

l ra

tes

(%)

1 2 30

5

10

15

20

25

30

N r

emov

al r

ates

(g/

m2 d

)

A/O zones and stages

NH4-N removal rates in A/O zone NH4-N removal rates in stage

NO3-N removal rates in A/O zone NO3-N removal rates in stage

TN removal rates in A/O zone TN removal rates in stage

Fig. 2. (a) Nitrogen concentrations in effluent and removal rates under ammonium (<41 d), nitrate (42-78

d) and nitrate and ammonium loadings (>78 d); and (b) the average nitrogen removal rates in A/O zones

(strip bars) and in the stages (grayscale bars).

The main ammonium transformation occurred in A/O zone 1 (6.8 g/m2 d), which was

equal to that in stage 1 (6.7 g/m2 d) (Fig. 2b). Column 2 was under strong reduction condition

with ORP -183 mV and suitable for denitrifying bacteria growth. Stage 1 presented

significant nitrate removal rate (11.1 g/m2 d) compared with 3.4 g/m

2 d in A/O zone 1. In

stage 2, a favorite environment for Dissimilatory Nitrate Reduction to Ammonium ammonia

(DNRA) can be found in column 4 (anoxic condition with ORP -102 mV). The DNRA

process can explain the slight rising of ammonium amounts at site 6 while the nitrate

decreased by 11.71 mg/L. At A/O zones, the higher AOB fraction relative to NOB was in

agreement with the higher growth yield and ammonium removal of AOB. Besides, all DGGE

bands were identified as β-proteobacteria with the potential for denitrification, which

accounted for predominant TN removal.

CONCLUSIONS

The small-scale system with A/O zones in series was established. ORP made the main

impact on nitrogen removal. The microbial diversity was highest at the A/O zone, mediate in

the aerobic zone, and lowest in the anaerobic zone. At the A/O zones, nitrification and

denitrification processes can occur together to remove nitroghen efficiently from the system.

REFERENCES Bettez, N.D. and Groffman, P.M. (2012) Denitrification potential in stormwater control structures and natural

riparian zones in an urban landscape. Environ Sci Technol. 46: 10.1021/es301409z.

Mermillod-Blondin, F., Mauclaire, L. and Montuelle, B. (2005) Use of slow filtration columns to assess oxygen

respiration, consumption of dissolved organic carbon, nitrogen transformations, and microbial parameters in

hyporheic sediments. Water Res. 39: 1687-1698.


303

Microbial activity in sludge treatment wetlands according to

depth and plant species (P.168)

Vincent Gagnona, Jacques Brisson

a, Florent Chazarenc

b

a Institut de Recherche en Biologie Végétale, Département de Sciences Biologiques,

Université de Montréal, 4101 Sherbrooke Est, Montréal (Québec), H1X 2B2, Canada.

([email protected], [email protected]) b

L’UNAM Université, École des Mines de Nantes, CNRS, GEPEA, UMR 6144, 4 rue Alfred

Kastler, B.P. 20722, F-44307 Nantes Cedex 3, France. ([email protected])

INTRODUCTION

Sludge treatment wetland (STW) is a specialised type of vertical flow constructed wetland

whose main function is to reduce sludge volume by dewatering and lower organic matter

content through mineralisation. Treatment processes include physical retention of sludge

particles at the surface, and percolation of a fraction of the sludge water through the

wetland’s granular media. In those system, the presence of plants and the choice of certain

plant species have been shown to enhance sludge mineralisation (Gagnon et al. 2013) and

reduce pollutants release at the STW outlet (Gagnon et al. 2012). The influence of plant on

treatment is generally explained by the rhizosphere effect, where the plant roots promote

microbial population responsible for the mineralisation of pollutants. Microbial processes are

considered as one of the main mechanism for pollutants removal in treatment wetlands. First,

microorganisms released extra cellular enzymes in their environment (phosphatase, lipase,

esterase, etc.), which breakdown pollutants into easily assimilable size. Subsequently the

microbial population used part of those compounds for their respiration process (aerobic

respiration, nitrification, denitrification, etc.) to further degrade the pollutants into generally

inoffensive molecules such as H2O, CO2, N2, etc. Although microorganism constitute key

element of this technology, few studies have measured their localisation within the STW or

the influence of plants on microbial process and treatment capacity. Therefore, the aim of this

study is to measure microbial enzymatic and respiration activities according to depth and

plant species.

METHODS

The experimental setup consisted of 8 mesocosms (cylindrical shape, height: 1 m;

diameter: 0.6 m) representing sludge treatment wetlands, each composed of 4 filter layers of

different granular sizes (layer of sand followed by gravel). Contrary to conventional STWs,

the experimental mesocosms were not completely drained, and a saturated layer was retained

by placing an overflow at 25 cm from the bottom. The mesocosms were planted with a

monoculture of Phragmites australis, Typha angustifolia and Scirpus fluviatilis, in addition to

an unplanted control, all in duplicate. The experiments were feed with fish farm sludge

during three summers at a final loading rate of 30 kg TS m-2

. Sampling for microbial analysis

was made according to depth. Microbial populations were extracted by shaking, using tap

water for the sludge and wetland water for the sand and gravel layer. General enzymatic

activities were measure with fluorescein diacetate (FDA) and specifics enzymes activity were

measured with a fluorescent substrate (4-MUB or 7-AMC) for phosphatase, glucosidase,

galactosidase and aminopeptidase. Microbial respiration was measured by dehydrogenase

activity with a tetrazolium salt (INT) according to manufacturer protocol. All microbial

measurements were extrapolated per surface of STW.


304


Fig. 1. Glucosidase activity according to plant species and depth. Statistical significance between plant

species is noted by capital letters and lower case letter represent significance according to depth per plant

species.

For each plant species, microbial activities occurred mainly in the sludge layer of the

STWs, while the sand and gravel layer had lower and generally similar values (Fig 1.).

Microbial activities were generally higher in STWs planted with Phragmites, while Typha

and Scirpus where sometime similar to Phragmites or to the unplanted control. Microbial

activities obtained in this study only partly explained the pollution removal observed at the

outlet of the STWs. For example, chemical oxygen demand (COD) was high at the outlet of

the unplanted control (175 g O2 m-2

) compared to the planted system (3-55 g O2 m-2

).

Nonetheless, the glycosidase activity did not present this pattern between planted and

unplanted STWs. This can be explained by the fact that microbial activity vary with time.

Thus the peek of microbial activity could have occurred earlier for some species and

consequently the activities at the moment of measurement were lower and similar to the

unplanted control.

CONCLUSIONS

Microbial activity occurred mainly in the sludge layer of the STWs. Plant species had

generally a higher influence on microbial activity, especially when planted with Phragmites.

However, the microbial activities did not totally explain the pollutant removal. Further

studies should look at the variation of microbial activity with time.

REFERENCES Gagnon, V., F. Chazarenc, M. Koiv and J. Brisson, (2012). Effect of plant species on water quality at the outlet

of a sludge treatment wetland. Water Res. 46(16): 5305-5315

Gagnon, V., F. Chazarenc, Y. Comeau and J. Brisson, (In Press). Effect of plant species on sludge dewatering

and fate of pollutants in sludge treatment wetlands. Ecol. Eng.

0

5

10

15

20

25

30

35

40

Slu

dge

Sand

Gra

vel

Slu

dge

Sand

Gra

vel

Slu

dge

Sand

Gra

vel

Slu

dge

Sand

Gra

vel

Phragmites Typha Scirpus Unplanted

MU

B G

luco

sid

ase (

mm

ol h

r-1 m

-2)

a

b b

a

b b

a

b b

a

b b

A B B B

Phragmites Typha Scirpus


305

Performance of a Multi-Stage Hybrid Constructed Wetland

System for Swine Wastewater Treatment in a Cold Climate (PO.115)

Kunihiko Katoa, Takashi Inoue

b, Hidehiro Ietsugu

c, Yasuhide Sugawara

d,

June Haradab, Hiroaki Sakuragi

b, Kitagawa Katsuji

c

a NARO Tohoku Agricultural Research Center, Shimo-Kuriyagawa, Morioka, Iwate, 020-

0198, JAPAN ([email protected]) b

Graduate School of Agriculture, Hokkaido University, N9W9, Kita-ku, Sapporo, Hokkaido,

060-8589, JAPAN ([email protected]) c

TUSK Co., Ltd., 2-8, Midorimachi-minami, Nakashibetsu-cho, Shibetsu-gun, Hokkaido

086-1166, JAPAN ([email protected]) d

NARO Hokkaido Agricultural Research Center, Hitsujigaoka-1, Toyohira-ku, Sapporo,

Hokkaido, 062-8555, JAPAN ([email protected])

INTRODUCTION

In November 2009, a multi-stage hybrid subsurface flow constructed wetland system was

installed for swine wastewater treatment in the City of Chitose, Hokkaido, northern Japan (N

42.817, E141.733). Mean annual temperature at Chitose is about 7.2 ◦C. Approximately 150

sows and 2,000 pigs are kept in the pig farm. The pig slurry is separated into liquid and solid,

and the liquid portion (swine urine) is treated by the multi-stage hybrid wetland system. We

outline the system design and its performance in this paper.

METHODS

The system is composed of four vertical (V) flow beds equipped with self-priming siphon,

one horizontal (H) flow bed and one lagoon reservoir. The total bed area is 1,472 m2. In the

first and second V flow bed, treated effluents are recirculated (Vr) by pump with timer to

improve performance especially in the growing season. Volcanic porous pumiceous gravel

and sand are used as the main bed materials (Fig. 1).

Fig. 1. A schematic diagram of the hybrid wetland system for swine wastewater treatment

To overcome clogging due to the high load in a cold climate, we applied a safety bypass

structure and floating cover material (Supersol®: lightweight porous glass recycled from

waste bottles) to the bed surface (Kato et al. 2013). The surface of the 1st V flow bed is

partitioned into three zones and the 2nd and 3rd beds into two zones, and used alternately to

maintain dry condition during the growing season following French systems (Molle et al.,

2005).

Siphon PP Pump Pump for recirculation

Reed ReedReed

1st Vr

572m2

2nd Vr

446m2

５th V

75m2

P

P

Pumice L

10-50mmPumice M

5- 10mm

Pumice L

10-50mm

P

out

Pumice M

5- 10mm

PP

Pumice S

1- 5 mm

3rd V

184m2

Solid – liquid

separation

Liquid

Reed

Pumice M

5- 10mm

P

４th H

195m2

recirculation

Pumice L

ALC50mm～

Pumice S

1- 5 mm

P

Lagoon reservoir

≈1000m3

P

Floating cover (Supersol)

Pumice M

5- 10mm

Pumice S

1- 5 mm

Pumice LP

Samplingｎ

1

2In

3

45

6

Piggery

slurry

recirculation


306

Water samples were collected and analysed in laboratory for more than once a month from

Nov. 2009 to Dec. 2012. Water flow was calculated by monitoring the change in the water

level at each self-priming siphon or pumping hall. The change in the water level was

measured every 10 minutes with a pressure-type water-level gauge and a data logger (S&DL

Mini; Oyo Corp., Tokyo, Japan) throughout the year.


Mean pollutant concentrations of inter-stage samples are shown in Table 1 along with the

purification rate. Mean flow rate, received load and removed load are shown in Table 2. Table 1. Mean pollutant concentrations of inter-stage samples (Aug. 2010 - Dec. 2012, n=41)

No severe clogging has been seen,

and the system worked throughout

the year. Purification rate of

BOD5, COD, T-N and NH4-N has

improved year after year. Mean

oxygen transfer rate was 48

gO2·m-2

·d-1

which was larger than

the previous studies (Cooper

2005).

CONCLUSIONS

Our multi-stage hybrid system

was able to treat swine wastewater

in high load and OTR without

severe clogging in a cold climate.

ACKNOWLEDGEMENTS

The authors would like to acknowledge the staff of the pig farm. Part of this study was

supported by the research program granted by the Ministry of Agriculture, Forestry and

Fisheries and the Ministry of the Environment, Japan.

REFERENCES Cooper, P. (2005) The performance of vertical flow constructed wetland systems with special reference to the

significance of oxygen transfer and hydraulic loading rates. Water Sci. Technol. 51(9), 81–90.

Kato, K. et al. (2013) Performance of six multi-stage hybrid wetland systems for treating high-content

wastewater in the cold climate of Hokkaido, Japan. Ecol. Eng. 51, 256–263.

Molle, P. et al. (2005) How to treat raw sewage with constructed wetlands: an overview of the French systems.

Water Sci. Technol. 51(9), 11–21.

In 1st Vr 2nd Vr 3rd V 4th H 5th V Purification rate %

BOD5 mg•l-1 2299 480 250 184 117 71 96.9

COD mg•l-1 6460 1918 1299 1054 751 526 91.9

SS mg•l-1 1275 70 184 122 53 38 97.0

T-N mg•l-1 1314 667 533 493 402 402 69.4

NH4-N mg•l-1 1157 518 384 331 273 175 84.9

NO3-N mg•l-1 30 58 79 84 90 159

T-P mg•l-1 137.3 35.5 29.1 23.8 18.0 12.4 91.0

T. Coliform ml-1 48852 2633 538 697 275 189 99.6

DO mg•l-1 2.5 3.5 3.5 4.0 3.6 4.5

pH 8.3 8.1 7.8 7.8 7.7 7.3

Table 2. Mean flow rate, received load and removed load

（Aug. 2010 - Dec. 2012）

1st 2nd 3rd 4th 5th Total

12.2 13.0 13.3 13.6 13.8 12.2

BOD5 49.2 14.0 18.1 12.8 21.6 19.1

COD 138 56 94 73 139 54

T-N 28.1 19.4 38.6 34.3 74.2 10.9

NH4-N 24.7 15.1 27.8 23.1 50.3 9.6

T-P 2.94 1.04 2.11 1.65 3.32 1.14

BOD5 38.9 6.7 4.8 4.7 8.6 18.5

COD 97.1 18.0 17.8 21.0 41.6 49.3

T-N 13.8 3.9 2.9 6.3 0.1 7.6

NH4-N 13.7 3.9 3.8 4.1 18.1 8.2

T-P 2.18 0.19 0.39 0.40 1.04 1.04

(g•m-2•d-1)

(g•m-2•d-1)

Stage

Flow rate (m3/d)

Received

load*

Removed

load**


307

Remediation performances of the Bambou-Assainissement® filter

for a food industry effluent (P.125)

Frédéric Panfilia, Marie Calvez

b, Charles Perrin

a, Véronique Arfi

a and Mathias

Welschbilligb

aPHYTOREM S.A., site d’Areva, chemin de l’autodrome, MIRAMAS, 13140, FRANCE

([email protected])

bEau et Industrie, 14, rue des écoles - Saint Nicolas des Eaux, 56930 Pluméliau, FRANCE

INTRODUCTION

The Bambou-Assainissement® is phytoremediation treatment using bamboos to remediate

wastewater. This patented technology was developed by the French company Phytorem.

Initially, a first version of the Bambou-Assainissement® treatment system was designed to

remediate mainly agricultural effluents (winery effluent and olive oil mill wastewater). For

this treatment system, the selected bamboos species are directly planted in the soil. In an

industrial context, important daily volumes of high loaded wastewater are produced, and in

this case, the use of soils to implement a Bambou-Assainissement® treatment system can be

limitative, mainly because in such industrial context, large areas would be necessary to

achieve the treatment. In order to treat food-industry wastewater, in the frame of the applied

research European project BRITER-WATER, we have designed and built a second version of

our treatment system, in which selected bamboo species are planted in filtration media

instead of being planted in soil. One of the major objectives of the project was to evaluate the

remediation performances of the Bambou-Assainissement® Filter (BAF) for food-industry

wastewater.

METHODS

A pilot plant of 1500 m2 (effective area) was implemented in spring 2010 for a major soft

drink manufacturer located near Valence (France). The total height of the bamboo filter is

about 1m, and 6 filtration materials were used for the 4 layers of the filter. The flow of the

effluent applies on the bamboo filter is vertical. The BAF is functioning since September

2010.

The remediation performances on the regulatory parameters (i.e. COD, BOD5, TSS, Nt

and Pt) were weekly monitored during 2 years (from September 2010 to August 2012). The

wastewater and treated water were collected with automatic refrigerated samplers (24 hours

samples). Chemical analyses were performed on site by the industrial partner.


During the 2 years of monitoring around 21 100 m3 of a high carbon loaded effluent (see

Tab. 1) were treated by the BAF, which represents an average of 30 m3 of wastewater treated

per day. As shown in the Fig. 1 and Tab.1, the BAF allows to reach good remediation

performances. The average remediation performances were 90, 93, 84 and 78 % for COD,

BOD, TSS and Pt respectively, and 43 % for Nt. For the wastewater treated in this study the

ratio DBO5/N/P was not well balanced, as it is often the case for industrial wastewater. By

balancing this ratio (noted “with optimisation” in Tab. 1), it was possible to improve the

average treatment efficiency up to 97, 97, 95 and 94 % for COD, BOD and TSS respectively. Fig. 2. Inlet and outlet COD concentrations and removal efficiency, during the 2 years of monitoring.


308

Tab. 1. Average wastewater and treated water concentrations for regulatory parameters, and average

removal efficiencies (confident interval at 95 %).

CONCLUSIONS

Thanks to the project BRITER-WATER, besides characterizing the remediation

performances of the system, the project also allowed us to optimize the sizing of the BAF to

improve its reliability and its remediation performances, and to define the investment and

exploitation costs.

ACKNOWLEDGEMENTS

The project was supported by the European Association for Creativity and Innovation

(EACI) in the frame of the CIP-Eco-innovation program (08/239063). Authors would like to

thanks the Délifruits factory from the Refresco Group, for assistance and financial support.


309

Effect of wastewater generated in a sugar mill on sugar cane in

experimental treatment wetlands. (P.157)

Rivas H. A.a, Figueroa Nancy

a

a Instituto Mexicano de Tecnologia del Agua (Mexican Institute of Water Technology). Av.

Paseo Cuauhnahuac Nº 8532 Col. Progreso. Jiutepec. Morelos. Mexico. C.P. 62550. ([email protected], [email protected])

INTRODUCTION

There are 16 sugar mills in Mexico. Most of them have no treatment plants due to

insufficient budget and sewage is discharged directly into rivers and lakes, affecting

biodiversity and productive activities associated with fishing. In some cases the waste water

is treated by stabilization ponds, which are systems with low costs of treatment, however

treatment of water is not sufficient and operating problems arise because usually they are

overloaded, so that the treatment is insufficient to meet Mexican standards for crop irrigation.

Faced with this problem, in previous years were evaluated two experimental treatment

wetlands with vertical flow, planted with sugarcane (Saccharum sp) in order to determine the

possibility of using the irrigation areas of sugarcane as treatment system of the wastewater

produced into the mills (Rivas and Figueroa, 2010). It was concluded that this it is feasible if

the irrigation system is improved, the groundwater depth should be greater than 1.2 m

(depending on soil type) and the sanitary wastewater should be treated by a compact

electromechanical system, with water disinfection included. However, farmers believed that

wastewater from the mill has characteristics that may affect the development and production

of sugar cane due to high concentrations of organic matter and temperatures around 40 ° C. Is

reported in this study the impact of wastewater generated in a sugar mill, on the development

of sugar cane.

METHODS

Three treatment experimental wetlands, each planted with sugarcane are evaluated. The

first wetland wastewater is irrigated with 100% generated in the mill, second is irrigated with

a mixture of 50% of spring water (clean water) and 50% residual water, the third wetland is

irrigated only with spring water. Were used three plastic containers 1.80 m long, 0.90 m wide

and 0.60 m depth. Were located inside of the sugar mill. Five individual plants of sugar cane

were selected randomly, labelled and measured its height over a period of 12 months with a

frequency of every 15 days.

The concentration of TN,T P, K, Ca, Mg, S, B, Cu, Fe, Mn, Mo, Zn) of root, stem and

leaves of the selected plants is evaluated.


Figure 1 shows the average height measured to the plants over a period of 342 days. In

wetland irrigated with 100% of wastewater were produced 28 individual canes, the five

selected grew on average 3.01 m; wetland watered with 50% of wastewater and 50% with

spring water, were produced 28 individuals and grew on average 3.22 m; wetland watered

with only with spring water, were produced 34 individuals and grew on average 2.89 m.

There is not a significant difference among the height in the three wetlands.


310

Fig. 1. Average height of sugar canes into the three wetlands. W.W. (Wastewater), S. W. (spring water).

Table 1 shows the results of TN,T P, K, Ca, Mg, S, B, Cu, Fe, Mn, Mo, Zn) of leaves,

stems and roots and of evaluated plants from the three wetlands. It can be observed a small

difference in the concentrations. Table 1 Results of TN, TP, K, Ca,Mg, S, B, cu, Fe, Mn, Mo and Zn) of leaves, stems and roots of plants

from the three wetlands.

Wetland1 (100% wastewater)

Part of the

plant

NT PT KT CaT MgT CuT MnT ZnT PbT CdT NiT FeT

% mg/L

Leaves 1.36 0.21 1.78 0.22 0.13 7 37 32 30 0.5 7 130

Stems 0.17 0.17 0.45 0.04 0.04 3 10 15 14 0.7 5 82

Roots 0.45 0.17 0.45 0.22 0.08 14 41 20 12 0.2 4 598

Wetland 2 (50% wastewater y 50% spring water)

Leaves 1.30 0.20 1.75 0.35 0.18 6 52 27 23 1.4 16 171

Stems 0.30 0.16 0.87 0.05 0.05 2 13 17 19 0 12 65

Roots 0.50 0.19 0.92 0.66 0.20 50 68 35 59 1.7 6 623

Wetland 3 (100% spring water)

Leaves 1.68 0.25 2.17 0.18 0.12 8 26 35 36 0.2 19 149

Stems 0.30 0.17 0.77 0.04 0.04 2 9 23 41 0.1 20 50

Roots 0.87 0.19 0.83 0.31 0.09 19 45 38 34 0 20 640

CONCLUSIONS

Is concluded that wastewater produced in the sugar mill do not significantly affect the

growth of plants, neither nor the assimilation of nutrients and minerals.

ACKNOWLEDGEMENTS Thanks to Casasano sugar mill, in Cuautla Morelos, for all the provided support for this study.

REFERENCES Rivas H. A and Figueroa G. N. E.. (2010). Tratamiento de las aguas residuales del Fideicomiso Ingenio

Casasano en un humedal de flujo intermitente. Informe final. “Treatment of wastewater generated in a sugar

mill of Casasano by an intermittent flow constructed wetland”. Final Report. 109 pp.

0

50

100

150

200

250

300

350

0 63 79 105 127 162 183 219 247 275 310 342

Pla

nts

heig

ht

h (

cm

)

Time (days)

Wetland 1 ( 100% W.W.)

Wetland 2 (50% W.W. and 50% S.W.)

Wetland 3 (100% S.W. )


311

SOC stocks of alluvial and dredged sediment soils near tidal

rivers in northern Belgium (PO.66)

Suzanna Lettensa, Bruno De Vos

a, Maarten Hens

a

aResearch Institute for Nature and Forest (INBO), Gaverstraat 4, Geraardsbergen, B-9500, BELGIUM

([email protected], [email protected], [email protected])

INTRODUCTION

Alluvial soils near rivers are often characterised by high clay content, high water table and

high organic matter content. However, since their total area is relatively small, a sufficient

number of samples may be lacking to accurately quantify their C stocks in large-scale C

inventories (e.g. Krogh et al., 2003; Meersmans et al., 2008).

We carried out a comprehensive soil survey of alluvial soils that are designated to function

as areas for controlled flooding and tidal marsh restoration in the near future. These

embanked areas are situated near tidal rivers in the northern part of Belgium (Flanders).

Additionally, we collected a large number of C measurements in soils where historical

deposition of dredged sediments occurred. This entailed both natural and human deposition

of sediments, since it is often impossible to distinguish between the two by field observations

alone.

The aim of the present study is to estimate C sequestration potential in alluvial soils and to

evaluate the relative importance of dredged sediment soils versus ordinary alluvial soils for C

sequestration.

METHODS

Alluvial soils

In total, 1195 soil samples were collected in 16 future controlled flooding areas near four

navigable rivers, covering a total surface of 2083 ha. Soil organic matter was measured by

loss-on-ignition (LOI). In order to compute TOC values from LOI, a linear model with

covariates LOI, % clay and CaCO3 content was constructed based upon a separate dataset of

alluvial soil samples. Soil bulk density was estimated based on a third dataset of dredged and

alluvial soil samples, with covariates TOC and % clay. Most measurements in alluvial soils

were limited to the upper 10cm.

Dredged sediment soils

Dredged sediment soils were sampled up to a depth of maximum 2 m. In total 1187 soil

samples from 597 sample points on dredged soils were analysed. The borders of the dredged

deposits could be delineated based on fieldwork, maps and archives of the institution that

manages these waterways. The 196 polygons (541 ha) are considered to be homogeneous

since they reflect similar dredging conditions. Organic matter was measured by LOI or the

Walkley-Black method. For approximately 20% of the soil samples, TOC measurements

were available as well and enabled the construction of a linear model to derive TOC from

either LOI or Walkley-Black measurements. Bulk density was predicted according to the

same model as for the alluvial soils.


TOC was predicted by LOI alone for both alluvial and dredged soils. CaCO3 content and

% clay were not, or only marginally significant. Bulk density was predicted based upon TOC

and % clay.

Figure 1 shows the average SOC stock of alluvial and dredged sediment soils. Alluvial

soils store on average 5.6 kg C / m² in the upper 10 cm, dredged soils store slightly less,


312

namely 4.0 kg C / m² on average. However, dredged sediment soils store high amounts of C

up to a considerable depth. In the upper 20 cm, 8.1 kg C / m² is stored, while in the upper 1

m, these soils contain 36 kg C / m². This means that the belowground C stock increases

almost linearly with increasing depth.

Fig. 1. SOC content of dredged and alluvial soils for different depths.

CONCLUSIONS

Soil organic carbon stocks of dredged sediment and alluvial soils along tidal rivers were

compared. Stocks did not differ much in the upper 10 cm of soil. However, deeper layers of

dredged sediment soils contain high C concentrations, which creates a large total C stock.

Obviously, the limited area of these soils compared to the total alluvial area will always

constrain their importance for C sequestration on a regional scale.

ACKNOWLEDGEMENTS

We would like to thank Waterwegen & Zeekanaal nv of the Flemish Government for their

financial support.

REFERENCES Krogh, L., Noergaarda, A., Hermansena, M., Greveb, M.H., Balstroema, T. and Breuning-Madsena, H. (2003)

Preliminary estimates of contemporary soil organic carbon stocks in Denmark using multiple datasets and four

scaling-up methods. Agriculture, Ecosystems & Environment 96:19-28.

Meersmans, J., De Ridder, F., Canters, F., De Baets, S. and Van Molle, M. (2008) A multiple regression

approach to assess the spatial distribution of Soil Organic Carbon (SOC) at the regional scale (Flanders,

Belgium). Geoderma 13:1-13.

Dredged 0-100cm

Dredged 0-20cm

Dredged 0-10cm

Alluvial 0-10cm

0 20 40 60 80 100

SOC (kg/m²)


313

Seasonal Performance of a Full-Scale Constructed Wetland

System for Sarnadas de Rodão (Portugal) Domestic Wastewater

Treatment (P.26)

M.C. Mesquitaa, A. Albuquerque

b, A. Albuquerque, F.A Carreiro

c, L. Amaral

d,

R. Nogueirae

a,cHigh School of Agriculture, Polytechnic Institute of Castelo Branco, Quinta da Senhora de

Mércules, Apartado 119, 6001-909 Castelo Branco, Portugal ([email protected] ,

presenting author)

bDepartment of Civil Engineering and Architecture, University of Beira Interior, Bloco II das

Engenharias, Calcada do Lameiro, 6201-001 Covilha, Portugal.( [email protected])

dDepartment of Sciences and Environmental Engineering, Faculty of Sciences and

Technology, New University of Lisbon, 2829-516 Caparica, Portugal. ([email protected])

e Institute for Sanitary Engineering and Waste Management Welfengarten 1 30167 Hannover,

Germany. (E-mail: [email protected])

INTRODUCTION

Constructed wetland (CW) subsurface flows are widely used throughout the world to treat

a wide variety of wastewater (Vymazal, 2005). In Portugal they operate from early nineties

(Galvão, 2009), despite over 80% of these systems have been built over the last ten years.

More than 300 CW are in operation in Portugal and most of them are one-stage wetland

systems and are based on macrophytes beds emerging subsurface horizontal flow (HSSF)

with the aim of obtaining a secondary treatment stage (Albuquerque et al., 2009). Seasonal

variations in organic matter and nitrogen compounds removals efficiency by CW have been

reported by some authors with treatment deterioration being evident in winter months.

However, it is uncertain whether the poor winter performances are due to cold temperatures

alone or are the resulted of combined factors like rain and evapotranspiration that are also

variable with year seasons. In fact, these climatic conditions could be altering the detention

time and phenomena related to dilution or concentration of the pollutant can also be different

in wet and dry seasons. On the other hand, the potential seasonalities in wetland pollution

reduction performance can also be related to the plant growth along spring and summer and

autumn and winter senescence. Also microbial processes are known that are temperature

dependent, therefore it is expected that pollutants removals may exhibit seasonal patterns at

these systems. The aim of the present study was to investigated the treatment performance

along the time in order to assess the contribution of seasonal variation to organic matter and

nitrogen compounds reductions in a HSSF-CW planted with Pragmites australis and treating

wastewater from a small village (Sarnadas de Rodão) of Central Region of Portugal.

METHODS

The full-scale CW system under investigations is situated in Beira Interior Region of

Portugal (rural areas of the Interior Central Region of Portugal) and is located at small village

Sarnadas de Rodão. The area is characterized by a climate temperate Mediterranean, with

marked continental effect, with high temperature ranges and almost all of the rainfall

concentrated in autumn/winter. Climatic characteristics of the region also highlight the fact

that summer is normally very dry. The average annual temperature varied between 8 ºC and

25 ºC and the average annual precipitation observed in the region is 818 mm. The wetland

system was set up in 2006 include a single bed covered a total surface area of 1120 m2, with a


314

depth of 0.60m and is filled with a mixture of gravel-sand-soil and was planted with

Pragmites australis. It serves a population of 550 inhabitants. The influent enters the

treatment plant with a mean hydraulic rate of approximately 60 m3/day. Biweekly water

samples were collected at the inflow (after primary treatment) and outflow of CW system

between August 2012 and February 2013 and analysed for pH, COD, TN, organic nitrogen

(org-N), NH4+-N, oxidized nitrogen (NOx-N) that is summation of nitrite nitrogen (NO2-N)

and nitrate nitrogen (NO3-N) and TSS. Water samples were analysed in accordance with the

Standard Methods for Examination of Water and Wastewater (APHA-AWWA-WEF, 2005).


Seasonal variations of air temperature weremeasured and the mean temperature during

monitoring period was 8.3 ºC, within the range which is favourable for microbial activity.

The highest mean influent temperatures (25 ºC) were reached in August and the lowest were

recorded in January (10 ºC), similar to the air temperature. The system showed a good

reduction efficiency of COD, with mean percent reduction was higher in summer (August

and September) (~70%) and lower during autumn (October and November) (~50%) and

winter (December, January and February) (58.7%). BOD5 removal efficiency was similar to

COD. The mean BOD5 and COD percent reductions were ~ 10% less efficient in colder

months compared to summer. The slightly increased in removal rates at summer period may

indicate the importance of biological mechanisms in the removal rates of theses parameters.

However, TSS removal that mainly occurs through sedimentation and trapped in the root

systems is less affected. High removal efficiency of TSS was observed along the entire

monitoring period with a percent removal ranged between 77.7% and 89%. The influent

concentration of TN showed high variability, particularly in autumn-winter and reductions

calculated on median values tend to be slightly higher in summer than autumn-winter.

Generally, along the entire monitoring period we observed NH4-N negative removal values,

because the lower temperatures observed throughout the colder months (< 10 º C) and at

warm month these negative values may due to litter decomposition, especially organic

nitrogen compounds. The precipitation along autumn-winter can also contribute for low

redox conditions and prevented nitrification of the available NH4-N. Generally, no NOx-N

reduction was observed.

CONCLUSIONS

The average performance obtained during the whole study period has not been very high.

However, there is some difference between the average values during the active growth of

wetland and warmer months and resting period (autumn-winter months) in which

performance fall cause the average value go to down as much as 10 times in some of the

parameters. The decline of CW treatment performance in these months can also attributed to

the precipitation that has fallen regularly during the autumn and winter along the monitoring

period. Rainfall could have contributed to the drainage of filter media adsorbed pollutants

and also reduce the hydraulic residence time.

REFERENCES Albuquerque A., Arendacz M., Gajewska M., Obarska–Pempkowiak H., Randerson P. & Kowalik P (2009)

Removal of organic matter and nitrogen in a HSSF constructed wetland under transient loads. Wat. Sci. and

Tech., 60(7): 1677-1682.

Galvão, A. (2009) Comportamento hidráulico e ambiental de zonas húmidas construídas para o tratamento de

águas residuais. Ph.D. Thesis, Universidade Técnica de Lisboa, Instituto Superior Técnico, Lisboa, Portugal. (in

Portuguese).

Vymazal, J. (2005). Horizontal sub-surface flow and hybrid constructed wetlands systems for wastewater

treatment. Ecol. Eng. 25: 478–90.


315

French Vertical Flow CW performances in tropical climate:

design adaptation (PO.110)

Eme C.a, Esser D.

b, Lacombe G.

c, Riegel C.

d, Molle P.

a

aIrstea, 5 rue de la Doua, Villeurbanne, 69226, FRANCE ([email protected]

[email protected]) bSINT, Chef Lieu, la Chapelle du Mont du Chat, 73370, FRANCE ([email protected])

cETIAGE, 4 av. des plages, Rémire-Montjoly, 97354, FRANCE ([email protected])

dSIEAM, BP289, Mamoudzou, 97600, FRANCE ([email protected])

INTRODUCTION

French Outermost Regions (Guadeloupe, Martinique, French Guiana, Mayotte and

Reunion Island), under tropical climate, have to comply to European and French regulations.

Physical distance and tropical climate induce technical specificities to wastewater

management including importation dependence, specific material sensibility to corrosion,

hydraulic load variations, etc. Moreover, a social consideration is required to underline

sanitation stakes into those areas, as different water uses may impact influent water quality.

In such context constructed wetlands appear to be adapted systems as they promote local

treatment, use mainly local material and are easy to operate. Due to the difficulty of sludge

management in island context, there is a clear interest to adapt the French Vertical Flow CW

(Molle et al., 2005). By co-treating sludge and wastewater with a minimum of technical

requirements and hydraulic overload acceptance (Molle et al., 2006), this process can offer a

sustainable solution to overseas territories small wastewater treatment units. Nevertheless, the

adaptation to tropical climate require to determine new design rules (area needed, number of

filters, plants species, material, …).

Since 2006, surveys of a real scale VFCW pilot are monitored in Hachenoua’s pilot in

Mayotte (Esser et al., 2006; Esser et al., 2010; Liénard, 2010). Recently, another VFCW

French model “Bois d’Opale 1”, constructed in 2010 in French Guiana has been monitored.

Those pilots’ performances are compared to French mainland VFCW feedbacks in order to

elaborate a tropical adaptation of this process.

METHODS

Pilot description

“Bois d’Opale 1” is situated in Macouria, French Guiana (5°00’50’’N, 52°28’27’’W, 3 m

elevation and equatorial climate). This real scale pilot is composed of a single stage of

VFCW fed with pumped raw sewage from a strict wastewater collector of a 300 PE

residential area. Two filters of 121 m² each are fed alternatively during 3.5 days followed by

3.5 days of rest. Filters are composed of 30 cm of 15/25 mm alluvial gravel (drainage layer)

on the bottom under 30 cm of 3/6 mm alluvial gravel (filtration layer) and planted by Arundo

donax on the first filter and Phragmites australis on the second. Recirculation of a 100% of

treated effluent to the inlet is in operation during surveys.

Hachenoua plant in Tsingoni, Mayotte (12°47’24’’S, 46°6’23’’E, 62 m elevation and

tropical savanna climate) is composed of one stage of two filters with 15 cm of 20/40 mm

gravel in the drainage layer, 15 cm of 6/10 mm gravel (transition layer) and on the top 80 cm

of 4/6 mm basaltic gravel (filtration layer). As the filtration layer is higher, an intermediate

aeration system is installed. The pilot is managed by cycles of 7/7 days feeding/resting

periods and planted by Thysanolaena maxima. Recirculation of treated effluent to the inlet is

possible.


316

Pilots surveys

24h refrigerated flow-composite samplings are conducted at the inlet and outlet of the

filters and samples are evaluated for COD, filtered COD, BOD, SS, TKN, NH4-N, NOx-N

and TP according to French standard methods. Hydraulic loading assessment is calculated

from pumping time following calibration adjusting or tipping bucket calibration and

recording.

“Bois d’Opale 1” survey in Guiana was conducted from November to December 2012.

Hachenoua survey in Mayotte was managed from 2006 to 2010 with a 100% recirculation in

operation and then in November 2012 without recirculation.


The oral presentation will discuss the performances measured on tropical filters in

comparison to French mainland climate. It will be shown how climate can impact

performances, allowing a foot print reduction of the filters. Treatment performances obtained

are improved compared to one stage filter in mainland context:

- Mayotte’s pilot presents higher COD, SS and TKN removal performances (94, 96

and 95% respectively) than Guiana’s pilot (82, 91 and 70% respectively). This

difference might come from the presence of a higher filtration layer at Mayotte,

climate conditions being considered as equivalent.

- Tropical pilots results are better than performance of a first stage of classical model

in French mainland (82, 89 and 60% for COD, SS and TKN respectively).

- Outlet concentrations are lower in tropical’s pilots (52, 18 and 5 mg.L-1

for

Mayotte and 92, 22 and 22 mg.L-1

for Guiana COD, SS, TKN respectively) as

recirculation is diluting effluents and allow to conform to French regulations.

These results will be used to discuss the design adaptation that can be done in tropical

climate to reduce the footprint.

CONCLUSIONS

Performances reported satisfy national quality standards with a single stage of filters.

Those experiences tend to valid the ambition of reducing footprints of this process in warmer

climate and reinforce the potential of development of CW in this context.

ACKNOWLEDGEMENTS

The authors would like to thanks Onema to support this research program and SIEAM

technical team.

REFERENCES Esser, D., Jusiak, P., and Liénard, A. (2006) The use of constructed wetlands for the treatment of effluents from

housing schemes and villages in an island in the tropics: the case of Mayotte. 10th International Conference on

Wetland Systems for Water Pollution Control, Lisbonne, september 2006.

Esser, D., Riegel, C., Boura, S., and Lienard, A. (2010) The use of constructed wetlands for the treatment of

effluents from housing schemes and villages in an island in the tropics: New results from Mayotte. 12th

International Conference on Wetland Systems for Water Pollution Control, Venise, april 2010.

Liénard, A. (2010) Suivi expérimental des filtres plantées de Hachenoua et de Totorossa Mayotte 2006-2010

(SIEAM, Cemagref, SINT).

Molle, P., Lienard, A., Boutin, C., Merlin, G., and Iwema, A. (2005) How to treat raw sewage with constructed

wetlands: an overview of the French systems. Water Sci Tech. 51, 11-21.

Molle, P., Liénard, A., Grasmick, A., and Iwema, A. (2006) Effect of reeds and feeding

operations on hydraulic behaviour of vertical flow constructed wetlands under hydraulic

overloads. Water Research 40, 606-612.


317

Phytoremediation. Treatment of Domestic Sewage in Small

Ukrainian Settlements (P.129)

Zakharchenko M.A.

Ukrainian Scientific Research Institute of Ecological Problems, 6 Bakulin Street, 61166 Kharkiv, UKRAINE

([email protected])

INTRODUCTION

The changing socioeconomic conditions in Ukraine in recent decades triggered a quite

widespread migration of people from de-facto disappearing small villages and single-

homestead rural settlements to small towns or district administrative centers. The growing

population of these small towns creates a number of problems, including collection and

treatment of domestic sewage. In the conditions of economic and energy crisis, reconstruction

of existing or construction and operation of new conventional treatment facilities (first of all,

aeration tanks) are not always possible. Therefore, the unsolved problem of domestic sewage

collection often leads to environmental problems. In addition, in the course of long-term

operation the majority of facilities have exhausted, to a substantial degree, their operational

resource and currently require complete overhaul of the majority of their blocks. Therefore, it

actually became necessary to switch treatment systems from intensive technologies to easy-

to-operate, extensive methods with low energy consumption based on the use of natural self-

treatment processes. In most countries of Western Europe, United States, Canada, and

countries of Asia, technologies using higher aquatic plants (called phytoremediation)

received widespread application in sewage treatment. Since these facilities use natural

wetlands overgrown with higher aquatic plants as the basis, in English-speaking countries

they are called ‘Constructed Wetlands’.

State of the problem

In Ukraine, facilities of this kind called ‘bioengineered treatment facilities’ (BEF) were

developed back in 1984-1993 by the Ukrainian Research & Development Institute of

Environmental Problems. These facilities (as in the case of constructed wetlands) combine

the treating and disinfecting effects of sand or crushed stone filters, soil-based treatment

facilities, and biological ponds overgrown with higher aquatic plants.

BEFs represent arbitrarily-shaped basins featuring an anti-filtration screen (polyethylene

film or clay layer), drainage system (collecting filtered and treated water) and filtering

stratum (sand, crushed stone) overgrown with higher aquatic plants (HAP) (reed, sedge, or

bulrush) located on the bottom or on the sides of it. As a rule, most of these structures

represent a cascade of two to four BEFs; drainage systems of various types and design carry

the treated water through HAP plantations and the root layer in the filtering stratum. Almost

all facilities of this type are located on the lands unusable in intensive agriculture [1].

As of 2009, there were over two hundred treatment facilities featuring higher aquatic

plants as the principal treating element at the various stages of implementation (design,

construction, operation) in Ukraine. Despite the widespread interest, the very process of

implementing these facilities goes slowly due to a number of reasons:

under conditions of rampant bureaucracy, approval of ready projects by the government

controlling authorities takes several years; construction is done by companies lacking

appropriate experience;existing BEFs are operated extremely irresponsibly, this time because

of the psychological factor: if these treatment facilities require ALMOST no operating

personnel, the operating personnel will be COMPLETELY NONEXISTENT.


318

METHODS

Bearing in mind the aforementioned particularities of BEF operation in Ukraine, we have

designed a facility which may treat domestic waste from small settlements during 50 years

without operating expenses.

As we know [2], phytoremediation facilities come in two main types: with free water

surface (FWS) and subsurface-flow (SSF). The latter type can be further classified as

horizontal flow and vertical flow facilities. They have different designs and are used in

different conditions. In the case of horizontal-flow BEFs, there is no sewage on the BEF

surface. The main problem with operation of phytoremediation facilities in Ukraine is the

regular operation of mechanical treatment block before the BEF cascade, or simply speaking,

regular cleaning of sediment traps. We found a simple solution to this problem by using a

BEF block with free water surface (FWS) instead of the standard sediment traps. This

structure looks like a basin or canal with the entire surface overgrown with higher aquatic

plants (HAP). The water is treated by horizontal filtration through HAP vegetation.

Parameters of the entire treatment complex are calculated to ensure that a facility completely

overgrown with HAP will remove up to 80% of non-dissolved contaminants from the

domestic sewage flowing through it. Parameters of this facility are designed for continued

sedimentation of suspended substances (and also floating particles, such as paper or plastic)

during 50 years. At the same time, thickness of sediment layer over the surface of the

facility’s bottom will not exceed 0.5-0.7 m during the entire 50 years. After that, the facility

must be cleaned of sediments and HAPs must be planted along the surface again, and the

facility will be ready for continued operation. Design of the treatment facility features 1 to 3

BEF blocks representing a combination of the facility with free water surface (FWS) and

subsurface-flow (SSF) facility. This facility has a sand filtering stratum and a drainage

system (10-15 cm thick crushed stone layer and drains) at its base. A water layer with

thickness ranging from 0.4 m in the summer to 0.8-10 m in the winter must be maintained

above the filtering stratum surface. The treatment complex ends with a free water surface

(FWS) facility responsible for final treatment. To be sure, every particular case may feature

different combinations of different phytoremediation facility types. But Ukraine already has

experience in operation of facilities of this type at the minimal (or rather completely without)

operating costs. They all are notable for quite reliable performance and autonomy: these

facilities continuously receive contaminated water from small settlements or individual

properties and treat it according to the standards effective in Ukraine (stricter than Europe!).

CONCLUSIONS

We see the prospects of bioengineered treatment facilities (a.k.a. constructed wetlands) for

Ukraine (especially given the present state of the national economy) in their wide

implementation in district administrative centers, small towns, at individual industrial,

household, or recreation properties. Low operating costs will really help maintain the water

treatment cost for the public at the existing level without increasing it. One of these facilities

can be viewed using Google Earth at the following coordinates: 50о17’35.70”N,

35o59’21.30”E (small town Zolochiv).

REFERENCES 1. Zakharchenko M., Dziubenko I., Ryzhykova I. The Experience of Exploitation of Constructed Wetlands in

Ukraine. 10th International Conference on Wetland Systems for Water Pollution Control (2005, Lisbon,

Portugal). 2005. рр. 56–59.

2. Kadlec, R.H.., 2003, Effects of Pollutant Speciation in Treatment Wetlands Design, Ecol. Eng 20. pp. 1 -16.


319

Implementation of a Two-Stage Vertical Flow Treatment

Wetland at a Ski Area (PO.138)

C.R. Allen1,2

, O.R. Stein1,2

, K.J. Davis1,2

, M.D. Burr2 , and W.L. Jones

1,2

1Department of Civil Engineering Montana State University, Bozeman, MT, 59717 USA

2Center for Biofilm Engineering, Montana State University, Bozeman, MT, 59717 USA

[email protected]

INTRODUCTION

A pilot scale, two-stage vertical flow treatment wetland was constructed at the Bridger

Bowl Ski Area outside of Bozeman, MT. (49°45’ N 110°53’ W elevation 1,900 m). The pilot

treatment system was designed to treat 3.8 m3 d

-1, approximately 1/3 of the ski area’s average

daily flow, and to act as a research station allowing experimentation with organic and

hydraulic loading rates. The ski area operates annually from November to April with peak

loading corresponding with low ambient temperatures and high snowfalls. The ski area

receives an annual average of 8.9 m snowfall with monthly average temperatures that range

from -6.9° to 6.3°C during the operating season.

The treatment system serves the lower mountain region of the ski area, which consists of

two lodges with full food service as well as several ancillary buildings. No overnight lodging

is currently available on-site. Low-flow water fixtures and waterless urinals decrease water

consumption and increase wastewater strength. After primary treatment, the average

concentrations of COD, total nitrogen, phosphorous, and alkalinity are approximately 900,

170, 18, and 900 mg l-1

respectively. Wastewater must be pumped approximately 730 m from

the base area septic tanks to the treatment system. Upon arrival at the treatment system

average influent water temperature is less than 6°C.

The pilot vertical flow treatment wetland system consists of two parallel trains of two

vertical wetland cells in series (four cells total, each with a surface area of 4.9 x 4.9 m and

approximately 1.2 m deep). The treatment layer of the first cells in series feature a coarser

media (gravel, d50≈ 5 mm), while the treatment layer in second series is a medium sand (d50≈

0.6 mm). Coarser drainage layers underlie the treatment layers and the treatment layer in the

cells is overlain by a gravel cover for frost protection.

METHODS

The basic operational scheme features a pump station which can deliver septic tank

effluent to the first cells in series. Different hydraulic loading rates can be applied to each

parallel cell. Effluent from the first cells is combined in a second pump station which applies

flow to the second cells in series. Again, different hydraulic loading rates can be applied to

each cell in parallel. Effluent from the second cell is combined in a third pump station which

can recycle water back to the first cells in series. Different recycle rates to each cell in

parallel are possible. This scheme offers maximum flexibility to vary hydraulic and organic

loads and recycle rates at several points within the system. Flow rates for each wetland cell

can be measured from the influent (pump calibration) and effluent (V notch weirs). Influent

chemical composition can be measured from each pump station and from the effluent of each

cell (grab samples or by utilizing time-averaged auto samplers). In addition, sample ports

have been incorporated within each cell to allow for vertical profiling of performance.

Systematically varying hydraulic loading and/or recycle rates allows for performance

evaluation over a wide range of operational possibilities.


320


onstruction of the wetland was completed in October of 2012, too late in the season for

planting to begin. The system was run as a two-stage gravel filter over the 2012/2013 ski

season. After preliminary testing of the hydraulic components of the system in November and

December, wastewater was directed to the wetland in January 2013. A loss of hydraulic

conductivity in the sand layer was noted and attributed to ice build-up resulting from the

inactivity of the system, low insulating snow pack, and cold weather spell with daytime highs

not exceeding -20°C. After two weeks of consistent operation, hydraulic conductivity of the

sand layer was improved and low temperatures appeared to have had no adverse effects on

the hydraulic performance of the system. In June of 2013 the wetland will be planted with

two species, Schoenoplectus acutus, and Carex utriculata. Both species will be tested for their

climate suitability and performance enhancing nutrient removal. Optimization and

monitoring of the system will continue for the next three years of operation. Data from the

first year of operation as a gravel bed system will be presented in the poster.

ACKNOWLEDGEMENTS

The authors wish to thank Carlos Arias and Günter Langergraber for helpful advice for the

system design criteria, Ray Center at Rocky Mountain Engineers for further engineering

services, the Montana Department of Environmental Quality for construction and monitoring

funds and the grewat folks at Bridger Bowl Inc. for providing the site and construction of the

system.


321

MULTI-FITOX – advanced wastewater treatment system using

aquatic emergent macrophytes. (PO.146)

Veríssimo Diasa , E.A.Kriksunov

b, N.M.Shchegolkova

c

a Independent Consultant, PORTUGAL, ( [email protected] )

INTRODUCTION

The paper presents a project of an advanced wastewater treatment system using aquatic

macrophytes, named MULTI-FITOX. The system represents an application of the

configuration presented by the author in the Barcelona Wetpol Conference (Dias, 2009).

MULTI-FITOX is designed mainly for domestic wastewater treatment but also it can be

used for the treatment of industrial and agricultural wastewaters.

METHODS

MULTI-FITOX includes pre-treatment and primary treatment stages followed by an

equalisation thank and the secondary/biological treatment in modules of three compartments

beds. Considering that a very substantial portion of the pollutants in municipal wastewater

appears as particulate and colloidal matter (Metcalf and Eddy Inc. 1998) (Levine and others,

1998), one of the goals of the MULTI-FITOX conception is to remove (before the

wastewater reaches the plant beds) as much of the particulate matter as economically feasible.

These advanced pre and primary treatments result in space saving in the total space required

by the plant, especially when combined with efficient constructed wetland process for the

removal of the soluble matter. In addition this configuration creates conditions for good

treatment performance. The equalization stage aims to bring stability to the biological

treatment. Each bed consists of 3 parallel compartments that can work separately or can be

hydraulically connected. Some other key parameters for the plant beds are: filtration material

– gravel; type of flow– vertical subsurface up flow; vegetation: emergent macrophytes;

aeration - each compartment is equipped with an aeration system (that can be turned off when

anoxic or anaerobic conditions are required). Wastewater can be fed into each compartment

separately or simultaneously into all of them; also each outlet can be turned on or off

separately. The paper will present the sizing criteria, the treatment goals, the main

construction information and the operation regime of MULTI-FITOX.

CONCLUSIONS

MULTI-FITOX is very versatile system; it can work like a “current constructed wetland”

with three parallel beds, but also it can be adapted to operate in different hydraulic regimes,

when the wastewater characteristics, discharge goals or scarcity of space require that. For the

instance MULTI-FITOX is only a design project but the author hope to build soon a real

plant.

REFERENCES Dias, V.D. (2009). Design of an Intensified Hybrid Wetland System for the Wastewater Treatment of an abattoir

in Fornalhas Velhas, Odemira, Portugal; WETPOL Conference, Barcelona .

Levine, A.D., Tchobanoglous, G. and Asano, T. (1985). Characterization of the size distribution of contaminants

in wastewater; Treatment and reuse implications. Journ. WPCF, 57, 2, p. 805 Munch, R., Metcalf and Eddy Inc. (1998). Wastewater Engineering, Treatment, Disposal, and Reuse. Tchobanoglous G,

Burton FL, Stensel HD (eds.), 4th edition, McGraw-Hill, New York, New York.



322

Species-specific effects of natural and commercial macrophytes

on methane and nitrous oxide emissions from wetlands (PO.20)

Sheng Zhoua,*

, Xiangfu Songa, Huifeng Sun

a, Zishi Fu

a, Guifa Chen

a, chang’e

Liua, Qi Pan

a

a Eco-environmental Protection Research Institute, Shanghai Academy of Agricultural

Sciences, 1000 Jinqi Road, Shanghai, 201403, China ([email protected])

INTRODUCTION

Natural wetland ecosystems with macrophytes play an important role in the global carbon

budget and have a great potential for exchange of the greenhouse gas (carbon dioxide (CO2),

nitrous oxide (N2O) and methane (CH4)) with the atmosphere. On the other hand, some

species of macrophytes are utilized in constructed wetland for wastewater treatment, which

might enhance greenhouse gas emission due to high loading of carbon and nitrogen in

constructed wetland. Furthermore, some macrophytes species are also cultivated widely for

commercial cash crop purpose, which are fertilized by synthesized nitrogen fertilizer.

However, the characteristics of greenhouse gas emission of most commercial macrophytes

are little known except rice plant.

It is of vital importance to understand how individual macrophytes plant species affect

greenhouse gas emissions in wetland ecosystems. This will in future promote an advanced

understanding of the possible feedback on the global climate and future climatic change due

to vegetation changes in species composition in wetlands or commercial cultivation. Thus,

the major objective of this study was to respectively investigate the individual effects of

macrophytes species on the greenhouse gas fluxes in a single specie wetland. Focusing

mainly on (1) How individual plant species affect the fluxes of greenhouse gas; (2) How

different nitrogen and carbon loading levels affect the fluxes of greenhouse gas as well as the

response of biomass production of reed.

METHODS

Study site and treatment

The site was positioned in the Zhuanghang Experimental Field of Shanghai Low-carbon

Agriculture Engineering Technology Research Centre (SLAERC), which located at the south

of Shanghai, China. We collected eight macrophyte species, which including Canna indica,

Typha orientalis, Phragmites australis, Acorus calamus, Scirpus validus, Thalia dealbata,

Iris wilsonii, Zizania latifolia. Besides these eight species, we also collected four

macrophytes that widely cultivated as commercial cash crop, including Sagittaria sagittifolia,

Eleocharis dulcis, Zizania latifolia (edible), Oryza sativa. Each specie was transplanted into a

separated experimental wetland plot (4 m×5 m) at approximately 20 tills/m2. One plot

without any macrophytes was constructed as control. Besides natural wetland plots for all

species, swine manure was applied into four additional Phragmites australis plots at different

loading rates to investigate the CH4 and N2O emissions and CO2 uptake under different

carbon and nitrogen loading rates.

Sampling and analysis

Leaf area and biomass production were investigated during vegetation period. The closed

transparent chamber method was used for gas sampling which was done in triplicate in each

plot. The chambers had a pressure-adjusting bag, a fan and a three-way stopcock. Gas

samples inside the chamber were collected at 0, 6, 12, and 18 min intervals after chamber

placement through an automatic sampling system into a 1000 mL bag with aluminum liner.


323

Gas sampling was conducted once a month. During gas sampling, a soil Eh measurement at 5

cm depth was taken with a platinum electrode and an Ag/AgCl reference electrode. During

the experimental period, the water level was controlled at 10-15 cm. Gas samples were

analyzed by a gas chromatography (Agilent 7820A GC system) equipped with an AGS-1201

autosampler and N2 as the carrier gas. We used an ECD detector for N2O measurements

while an FID detector used for CH4 measurement. The CO2 was reduced into CH4 by H2

through nickel catalyst and then detected by the same FID detector.


The GWP (Global Warming

Potential) of N2O flux in each

species was significantly lower than

the CH4 emission. Compared with

the control plot (Fig.1), all of the

plots with macrophytes increased

CH4 emission fluxes, suggesting that

macrophytes could be a gas

transport channel. Additionally, the

CH4 fluxes are significantly

different among species. The

Zizania latifolia (edible) shows the

highest CH4 flux (25.6 mg-C/m2/h)

while the Canna indica has the

lowest CH4 flux (0.5 mg-C/m2/h).

The CH4 flux (13.8 mg-C/m2/h) of

Oryza Sativa is similar with other

rice varieties in the literature.

On the other hand, the CO2 assimilation fluxes showed different trends with CH4 fluxes.

The highest CO2 fluxes of five species (Canna indica, Typha orientalis, Phragmites australis,

Scirpus validus, Thalia dealbata) also obtained relative higher leaf area and biomass

production than other species. On the contrary, Zizania latifolia and Zizania latifolia (edible)

have the highest CH4 fluxes while relative lower CO2 assimilation fluxes, which resulted in

the highest percentages of emitted CH4-C to assimilated CO2-C of Zizania latifolia.

CONCLUSIONS

The N2O fluxes of most species are lower while the CH4 fluxes are higher and

significantly different among species. The Zizania latifolia shows the highest CH4 fluxes and

the highest percentage of emitted CH4-C to assimilated CO2-C.

ACKNOWLEDGEMENTS

This research was supported in part by a project (2012ZX07101-009) in National Science

and Technology Major Project-Water body pollution control and treatment, China.

REFERENCES Hendrikus J. Laanbroek (2010) Methane emission from natural wetlands: interplay between emergent

macrophytes and soil microbial processes. A mini-review. Annals of Botany 105:141-153.

Strom L., Mastepanov M. and Christensen T. R. (2005) Species-specific effects of vascular plants on carbon

turnover and methane emissions from wetlands. Biogeochemistry 75:65-82.

0

10

20

30

CH

4-C

flu

x

(mg/m

2/h

)

-900

-600

-300

0

Contro

l

Canna in

dica

Typ

ha o

rienta

lis

Phra

gm

ites austra

lis

Aco

rus ca

lam

us

Scirp

us va

lidus

Sagitta

ria sa

gittifo

lia

Thalia

dea

lbata

Iris wilso

nii

Eleo

charis d

ulcis

Oryza

sativa

Ziza

nia

latifo

lia

Ziza

nia

latifo

lia (ed

ible)

CO

2-C

flu

x

(mg

/m2/h

)

0

5

10

CH

4-C

/CO

2-C

(%)

Fig. 1. CH4-C emission fluxes, CO2-C assimilation fluxes,

and the percentages of emitted CH4-C to assimilated CO2-C

of each macrophyte specie.


324

Preliminary results on methane emission from horizontal

subsurface flow treatment wetlands as function of primary

treatment (PO.107)

Clara Corbellaa and Jaume Puigagut

a

a GEMMA – Group of Environmental Engineering and Microbiology, Department of Hydraulic, Maritime and

Environmental Engineering, Universitat Politècnica de Catalunya-BarcelonaTech, C/Jordi Girona, 1-3,

Building D1, E-08034, Barcelona, Spain (Email: [email protected], [email protected])

INTRODUCTION

Horizontal subsurface flow treatment wetlands (SSF TW) are bioreactors where the

organic matter contained in domestic wastewater is degraded mainly by anaerobic reactions

(Calheiros et al., 2009). Therefore, methane is emitted in SSF TW during wastewater

treatment. Recently, Hydrolytic up-flow sludge blanket (HUSB) reactor is being considered

as a suitable primary treatment for SSF TW (Pedescoll et al. 2011). However, effluents from

a HUSB reactor are of more reduced nature when compared to conventional settling and may,

therefore, enhance anaerobic pathways of organic matter degradation (such as

methanogenesis) when compared to wetlands coupled to conventional primary settling. The

purpose of this study was to determine whether anaerobic primary treatment of domestic

wastewater increases methane emissions from constructed wetlands when compared to

wetlands in which primary treatment is that of conventional settling.

METHODS

Emissions were measured from a constructed wetland pilot plant that consisted of 4

wetlands of 0,4 m2 each treating a flow of 21 L day

-1 of urban wastewater. All four wetlands

were planted with common reed a year before. The HUSB line was set in operation in May

2012 and had been fed with settler wastewater the year before. Two of the wetlands were fed

with settled wastewater whereas the remaining two were fed with the effluent of a HUSB

reactor. Methane emissions measurement was carried out in July, September and October

2012 following the closed chamber method (Livingston and Hutchinson, 1995). The closed

chamber employed consisted of a PVC cylindrical reservoir of 5 litres of effective volume.

Methane emissions measurements as well as chamber design were carried out following

Livingston and Hutchinson (1995). Once the chamber was located on the wetland, samples

were extracted after 0, 10 and 20 minutes and immediately analysed by gas chromatography

(Agilent Technologies, 7820A GC System). Methane emission rates were calculated

assuming a linear emission pattern. Physico-chemical analyses (such as COD and ammonia)

were also analyzed on a mass balance basis at the influent and effluent of the wetlands and

carried out according to Standard Methods (APHA-AWWA-WEF, 2005).


Preliminary results indicate that methane emissions are higher in those wetlands with the

HUSB reactor as a primary treatment than those fed with primary settled wastewater. This

was especially evident for the September and October campaigns (Figure 1).

Estimated methane flux densities during the last two campaign for the HUSB line were ca.

70% and ca. 90% higher than the settler line, whereas for the first sampling campaign (July)

no significant differences were recorded between wetlands. This was probably due to the fact

that the wetlands of the HUSB line were fed until May with settled wastewater and the

system was probably not very different from the settler line during the first sampling

campaign.


325

July September October

Flu

x d

ensity (

mg C

H4

/ m

2-

day)

0

100

200

300

400

500

600

HUSB Line

SETTLER Line

The higher emissions detected for the HUSB line were probably due to the reduced

effluents typically found in such reactors (Pedescoll et al. 2011). Both redox potentials and

physico-chemical data (ammonia removal) confirmed the higher anaerobic environment for

the HUSB line. To this regard, redox measures at 15 cm depth of the HUSB line were

significantly lower than for the settler line (-227,72 ± 77,06 mV and -90,79 ± 111,80 mV, to

the HUSB line and the settler line, respectively). Furthermore, COD removal was not

significantly different among treatment lines, whereas ammonia concentrations at the effluent

of the HUSB line were systematically higher than those of the settler line (Table 1). Lower

redox conditions and higher ammonia concentrations at the effluent of the HUSB line

confirm the higher importance of anaerobic pathways (such as methanogenesis) when

compared to the settler. Fig. 1. Flux densities obtained as function of the sample campaign.

Table 1. COD and ammonia removal for the HUSB and settler line - Mean (SD)

IN OUT % removal

COD HUSB (mg O2 L-1

) 329,81 (140,64) 148,47 (85,98) 55,0

SETTLER (mg O2 L-1

) 279,28 (102,42) 87,57 (70,45) 68,6

AMMONIA HUSB (mg L-1

) 41,91 (20,59) 2,49 (2,76) 94,0

SETTLER (mg L-1

) 34,51 (17,45) 0,96 (0,69) 97,2

CONCLUSIONS

The preliminary results obtained in this study indicate that methane emissions in wetlands

are influenced by the of type primary treatment applied. Accordingly, a wetland fed with

HUSB effluents not only shows lower redox conditions and lower ammonia removal but also

shows methane emissions between 70 to 90% higher than those of a wetland fed with primary

settled wastewater.

ACKNOWLEDGEMENTS This study was funded by the Spanish Ministry of Science and Innovation (MICINN) (projectCTM2010-

17750).

REFERENCES Calheiros, C., Duque, A., Moura, A., Henriques, I., Correia, A., Rangel, A., Castro, P. (2009) Substrate effect on

bacterial communities from constructed wetlands planted with Typha latifolia treating industrial wastewater.

Ecological Engineering 35: 744-753.

Livingston, G.P., Hutchinson, G.L.(1995) Enclosure-based measurement of trace gas exchange: applications and

sources of error. In: Matson, P.A., Harris, R.C. (Eds.) Biogenic Trace Gases: Measuring Emissions from Soil

and Water. Blackwell Science Ltd Oxford. pp. 14-51.


326

Methane emissions from Russian wetlands: the state of the

problem (P.134)

Verissimo N. Diasa, Mikhail V. Glagolev

b,c,d, Ilya V. Filippov

c, Irina

E. Kleptsovac, Shamil S. Maksyutov

e, Evgeny Shein

b

aIndependant Consultant, PORTUGAL ([email protected])

bMoscow State University, 1 Leninskiye Gory, Moscow 119991, Russia

([email protected])

cYugorsky State University, 16 Chehova Street, Chanty-Mansyisk, Tyumen region 628012,

Russia ([email protected])

dInstitute of Forest Science, Uspenskoe, Moscow region, 143030, Russia

eNational Institute for Environmental Studies, 16-2 Onogava, Tsukuba, 305-8506, Japan

INTRODUCTION

Methane is an important component of atmospheric photochemistry and the climate

system. The inventory showed by Cicerone and Oremland [1988] indicated that the main

natural soil’s sources of methane are wetlands. The Russia is likely an important source of

methane because of its large area of wetlands [Andronova and Karol, 1993].

METHODS

[Glagolev and Filippov, 2011] point out that regional methane flows evaluation methods

can be subdivided among three categories: simple inventory methods, direct mathematical

modeling methods and inverse modeling. For the evaluation of regional methane flows,

regardless of the mathematical tools employed, results should be given in whatever

carthographical basis is chosen. Particularly, in order to evaluate the regional methane flows

in wetlands, we use the GLWD3 database [Lehner and Döll, 2004], GlobCover v. 2.3

[Bontemps et al., 2011], “Peatland Ecosystems of Russia” [Vompersky et al., 2011] and the

wetlands carthography system we developed, PeatMap1.


Andronova and Karol [1993], using simple mathematical models related to soil carbon

flows, obtained the value 5.6 TgC/yr-1

. However, our calculations using the same

mathematical model show that emissions vary significantly (up to 100%) depending on the

chosen carthography, reaching for the highest-precision maps (PeatMap1, PER) values of 9.7

and 10.1 TgC/yr-1

. Therefore, different methods applied to the same maps produce much

smaller variations (20-30%). Generally, CH4 emissions in russian wetlands, as calculated by

us in PeatMap1 and PER maps, using 5 simple models, lie in the range of 9.7-13.5 TgC/yr-1

.

Attempts to inventariate wetlands methane emissions in Russia were also made by

Rozanov [1995] and Zelenev [1996]. These two authors defined for the whole Russian area

21 different kinds of methane-releasing soils. However, the underlying experimental dataset

was shown to be completely insufficient: in the first stage of the work only results from 43

CH4 emissions measurements in Russia and 99 outside it were included, and in the second

stage measurements totaled slightly over 500 (comprising both Russia and its outside

regions). These measurements address the issue of soil variability in a very unbalanced way,

given that [Rozanov, 1995] for 7 kinds of soils no measurements were taken and for 6 of

them only 1-2 data samples were gathered [Zelenev, 1996]. As a result of this work,



327

[Rozanov, 1995], considers that methane emissions in Russia are, on average, 2.7-82.3

TgC/yr-1

.

Mikaloff Fletcher et al. [2004] evaluate the CH4 flow in Russia to be of around

29.9 TgC/yr-1

. Considering that these results were obtained using inverse modeling, these

flows refer to all sources. Taking also into consideration the calculations of

[Kondratyev et al., 2003], who consider that wetlands release between 35-50% of all methane

emissions in Russia, one obtains the value of 10.5-15.0 TgC/yr-1

. This same author presents

the value 12.3-17.6 TgC/yr-1

, without any reference to what method was applied. Slightly

greater values can be found in the work of [Dolman and Shvidenko, 2013], considering that

Russian wetlands release 68% of all methane within the boundaries of the former Sovietic

Union [Andronova and Karol, 1993].

CONCLUSIONS

Current data for CH4 emissions in Russian wetlands (considering both our and other

researchers’ calculations) and resorting to different methods do not diverge significantly,

varying between 13.1-13.5 TgC/yr-1

.

ACKNOWLEDGEMENTS

The authors acknowledge the financial support by the European Union FP7-ENV project

PAGE21 under contract number GA282700.

REFERENCES Andronova, N.G. and Karol, I.L. (1993) The contribution of USSR sources to global methane emission.

Chemosphere. 26:111-126.

Bontemps, S., Defourney, P., Van Bogaert, E., Arino, O., Kalogirou, V. and Perez, J.R (2011) GLOBCOVER

2009: products description and validation report URL: http://due.esrin.esa.

int/globcover/LandCover2009/GLOBCOVER2009_Validation_Report_2.2.pdf

Cicerone, R.J and Oremland, R.S. (1988) Biogeochemical aspects of atmospheric methane. Global

Biogeochemical Cycles. 2:299-327.

Dolman, H. and Shvidenko, A.(2013) The carbon balance of Russia. Geophys. Res. Abstracts. 15:EGU2013-

1888. URL: http://adsabs.harvard.edu/abs/2013EGUGA..15.1888D

Glagolev, M.V. and Filippov, I.V. (2011) Inventory of soil methane consumption. Environmental Dynamics and

Global Climate Change. 2:EDCCrev0002. URL: http://www.ugrasu.ru/uploads/files/EDCC_2_2_Glagolev.pdf.

(In Russian).

Kondratyev, K.Ya., Krapivin, V.F. and Savinykh, V.P. (2003) Perspectives of civilization development:

multidimensional analysis. Logos Moscow. 576p. (in Russian)

Lehner, B. and Döll, P. (2004) Development and validation of a global database of lakes, reservoirs and

wetlands. Journal of Hydrology. 296:1-22.

Mikaloff-Fletcher, S.E., Tans, P.P., Bruhwiler, L.M., Miller, J.B. and Heimann, M. (2004) CH4 sources

estimated from atmospheric observations of CH4 and its 13

C/12

C isotopic ratios: 2. Inverse modeling of CH4

fluxes from geographical regions. Global Biogeochem Cycles. 18:GB4005.

Rozanov, A.B. (1995) Methane Emission from Forest and Agricultural Land in Russia (WP-95-31).

International Institute for Applied Systems Analysis Laxenburg. 73p.

Vompersky, S.E, Sirin, A.A, Sal’nikov, A.A, Tsyganova, O.P. and Valyaeva, N.A. (2011) Estimation of forest

cover extent over peatlands and paludified shallow-peat lands in Russia. Contemporary Problems of Ecology.

4:734-741.

Zelenev, V.V. (1996) Assessment of the Average Annual Methane Flux from the Soils of Russia (WP-96-51).

International Institute for Applied Systems Analysis Laxenburg. 45p.


328

Evaluation of commercially valuable halophytes for use in

constructed wetlands for mariculture wastewater remediation. (PO.51)

J.M. Webba, R. Quintã

a, D.N. Thomas

b, R. Santos

c, L. Le Vay

a

aCentre for Applied Marine Sciences – Bangor University, Menai Bridge, Anglesey, LL59

5AB, UK ([email protected] – [email protected] – [email protected])

bSchool of Ocean Sciences, Bangor University, Menai Bridge, Anglesey, LL59 5AB, UK

([email protected])

cAlgae-Marine Ecology Research Group, Centre of Marine Sciences, University of Algarve,

Campus of Gambelas, 8005-139 Faro, Portugal ([email protected])

INTRODUCTION

The use of commercially valuable halophyte species as emergent macrophytes in

constructed wetlands (CWs) and hydroponic systems for treatment of saline wastewater is a

novel approach offering dual outcomes: cost effective wastewater treatment and an additional

income from plant crops. It offers treatment solutions for intensive land-based mariculture

systems producing nitrogen rich effluent. The annual halophyte Salicornia europaea and the

perennial Aster tripolium are suitable candidates, valuable as gourmet vegetables, and also

used in animal feeds and in the nutraceuticals industry (Ventura and Sagi, 2012).

This study set out to evaluate the role of both S. europaea and A. tripolium in remediation

of total dissolved inorganic nitrogen (TDIN) from nitrogen rich mariculture wastewater.

METHODS

Triplicate pilot CWs were installed in a poly-tunnel, on an intensive marine fish farm in

North Wales, UK. Each CW measured 1m x 14.5m x 0.3m, W x L x H. Construction

consisted of rubber-lined timber frames filled with 40 mm limestone pebbles overlaid with a

layer of ≤6 mm quarry sand (Fig. 1). The two layers were separated by semi-permeable

barrier. Two-month old S. europaea plants were transplanted into the filter beds at a density

of 90 m-2

. The CW received wastewater from the fish farm and operated on a batch-

treatment, flood and drain system, retention time was 24 h. Water samples were taken at 0

and 24h after filling, three times a week from each of the 3 filter beds over 88 days and

underwent analysis for dissolved nutrients. After 58 days operating under ambient N loading

N levels in wastewater were artificially increased by adding ammonium nitrate fertiliser.

Figure 1. Cross-section of pilot filter bed

In addition, over a six month period, a study was conducted into N uptake and growth in S.

europaea and A. tripolium in a hydroponic floating raft filter bed system. Plants (density:

100m-2

) were supplied with artificial mariculture wastewater where N concentration was kept

above 1000µmol l-1

. In the hydroponic system, mid-season plant N uptake was measured

using a 15

N isotope enriched solution.






329

Every 3 weeks plants were removed from the CW and filter beds for biomass and C:N

analysis, in addition all S. europaea growth 10cm above the CW surface was harvested and

termed yield, whilst for A. tripolium part of the leaves were removed for the yield.


When processing fish farm wastewater at ambient concentrations (93 to 439 µmol l-1

) the

CW planted with S. europaea removed 97 to 100% TDIN. This compares well to Lin et al.,

2002 in which a CW planted with Phragmites australis removed 95 to 98% of the 11 to 1537

µmol TDIN l-1

and is in excess of that recorded by Zachritz et al., 2008 who saw removal of

37% of influent TDIN. During the period of increased N loading (2391 to 8185 µmol l-1

)

although efficiency decreased to 30 to 58% overall uptake increased to 2894 ± 408µmol N l-1

.

At this time, the highest removal rate observed (263 mmol N m-2

d-1

) greatly exceeded those

reported in previous CWs studies (Lin et al., 2002, Zachritz et al., 2008). By comparison the

estimated daily N uptake rates in the hydroponic filter bed system was 200 mmol N m-2

d-1

for S. europaea and 62 mmol N m-2

d-1

for A. tripolium.

Over the entire growth season the CW removed 1.3 ± 0.1 mol N m-2

and over the same

period total estimated N accumulation in plant tissue was 1.1 mol N m-2

. This would indicate

that 85% of N removed by the CW was assimilated by S. europaea. This is low in

comparison to a greenhouse experiment where S. europaea plants receiving N levels in

excess of 300µmol l-1

removed an estimated 6.53 mol N m-2

in a growth season (Quintã,

2012).

Over the experimental period the CW produced a mean yield of 0.9 ± 0.5 kg m-2

. Yield

fluctuated widely, with the lowest yield of 0.4 ± 0.1 kg m-2

observed under ambient N loading

and the maximum yield of 1.7 ± 0.2 kg m-2

observed following the period of high N loading

this is low compared to the yields achieved by Ventura and Sagi, 2012. In the hydroponic

system S. europaea yields varied between 0.2 and 2.9 kg m-2

whilst A. tripolium achieved

yields of between 1 and 2 kg m-2

.

CONCLUSIONS

CWs planted with the annual S. europaea represent a cost effective and efficient seasonal

solution to the problem of nitrogen loaded wastewater produced by intensive land-based

mariculture. Hydroponic culture indicates that inclusion of the perennial A. tripolium in the

CW may allow year round remediation. Regular plant harvests may provide a useful

secondary income from sale of fresh yield.

ACKNOWLEDGEMENTS

CW work was supported by a EU FP6 CRAFT project, Envirophyte (COOP-CT-2006-

032167) and hydroponic work by the SEAFARE project, EU Atlantic Area Transnational

Programme (2007 - 2013) under grant agreement no2009-1/123. RQ was supported by FCT

Portugal PhD grant (SFRH/BD/43234/2008)

REFERENCES Lin, Y.F., Jing, S.R., Lee, D.Y. and Wang, T.W. (2002) Nutrient removal from aquaculture wastewater using a

constructed wetlands system. Aquaculture 209, 169-184.

Quintã, R.F. (2012) Effectiveness of halophytic plants in the treatment of marine aquaculture wastewater. PhD

Thesis.

Ventura, Y. and Sagi, M. (in press) Halophyte crop cultivation: The case for Salicornia and Sarcocornia.

Environmental and Experimental Botany.

Zacharitz, W. H., Hanson, A.T., Sauceda, J.A. and Fitzsimmons, K.M. (2008) Evaluation of submerged surface

flow (SSF) constructed wetlands for recirculating tilapia production systems. Aquaculture Engineering 39:16-

23.


330

Effects of hydraulic loading rates and planting on the treatment

of organic matter and nutrients in tropical constructed wetlands (PO.90)

CF Gutiérrez a, MR Peña

a, EJ Peña

b

a Instituto Cinara, Universidad del Valle, A.A 25157, Cali, Colombia

([email protected]; [email protected])

b Departamento de Biología, Universidad del Valle, A.A. 25360, Cali, Colombia

([email protected])

INTRODUCTION

In constructed wetlands some authors report that the direct assimilation of nutrients by

plants is not representative, since in the absence of plants substrate itself and micro biota

provide a significant treatment of wastewater. In contrast, recent findings reported an

improved removal when plants are present, being this significantly higher in systems

operating at low loading rates. On the other hand, vegetation display features which are

specific to each species, and are also associated with the nature of the effluent and the

maturity of the wetland; vegetation features even vary according to environmental conditions.

Thus, the aims of this research were to investigate the effects of three different hydraulic

loading rates on the removal efficiencies of organic matter and nutrients in three experimental

units of subsurface flow constructed wetlands-SSCW. Moreover, also compare the effects of

the three hydraulic loading rates on the physiological responses of he macrophytes grown in

each SSCW.

METHODS

Three pilot-scale SSCW units (i.e., each one 27 m2) were built at the Research Station on

Wastewater Treatment and Reuse of ACUAVALLE, in the town of Ginebra, Southwest

Colombia. One SSCW was planted with the native tropical flower species Heliconia

psittacorum; the second SSCW with the foreign species Phragmites australis, and the third

SSCW had no plants and was the control unit. The SSCW units were filled with three

different gravel types: the support medium used was composed of a bottom layer of medium

gravel (3/4") 0.5 m depth, a middle layer of fine gravel (3/8") 0.05 m depth, and an upper

inert layer of fly-ash of 0.05 m depth. The SSCW units were loaded randomly with domestic

wastewater in three trials (Table 1), everyone lasted in average 6 months, with hydraulic

loading rates of 1.73, 3.46 and 5.18 m3 d

-1 (treatments: 1, 2, and 3, respectively).

Table 1. Hydraulic loads randomly applied in the SSCW units.

SSCW Unit Trial 1* Trial 2* Trial 3*

Heliconia sp. Treatment 1 Treatment 3 Treatment 2

Unplanted Treatment 2 Treatment 1 Treatment 3

Phragmites sp. Treatment 3 Treatment 2 Treatment 1

* Treatment 1: 1.73 m3d

-1 Treatment 2: 3.46 m

3 d

-1 Treatment 3: 5.18 m

3 d

-1

Each system received average concentrations (mg L-1

) of 157.2 (± 37.8) COD, 119.7 (±

26.5) BOD5, 48.9 (± 11.3) N-NH4+ and 4.3 (± 1.3) P-PO4

-3, respectively. The influent came

from an anaerobic pond working as primary treatment unit.

We made statistical comparison (both on loads and removal efficiencies for each

parameter) among SSCW units to find significant differences (p > 0,05). Respect to loads

removed (Table 2), which reached the highest results in each CW unit during the treatment 3,

we found that the COD were difference between the unplanted unit (highest average) and


331

other ones, which did not differ between them; in the case of BOD5 there were no differences

(highest averages) between the unplanted and Phragmites units; to N-NH4+

we only found

differences between Phragmites (highest average) and Heliconia units; finally, in the case of

P-PO4-3

there were differences between Phragmites (higher average) and other units.

Table 2. Summary of average loads removed (g m2 d

-1) in each of the SSCW units during each treatment.

Parameter Heliconia sp. Unplanted Phragmites sp.

1 2 3 1 2 3 1 2 3

COD 5.56

(1.40)

18.89

(8.33)

15.25

(5.48)

6.58

(2.74)

10.53

(1.88)

31.43

(10.28)

11.54

(3.88)

10.72

(5.81)

19.50

(6.65)

BOD5 5.21

(0.96)

14.03

(5.07)

11.72

(4.69)

5.01

(1.32)

9.61

(1.47)

20.15

(6.49)

8.23

(2.91)

10.32

(2.91)

16.23

(2.38)

N-NH4+ 0.89

(0.58)

0.34

(1.30)

1.04

(1.80)

0.43

(0.69)

0.71

(0.98)

0.81

(3.01)

1.28

(0.64)

2.46

(2.14)

2.87

(1.27)

P-PO43-

0.05

(0.09)

–1.74

(2.16)

-2.01

(2.48)

0.07

(0.13)

-4.13

(0.48)

0.07

(0.12)

0.06

(0.07)

0.21

(0.22)

-4.69

(0.98)

Regarding removal efficiencies (Table 3), SSCW units performed better during treatment

1, with the exception of COD in the unplanted unit (treatment 3). In contrast, in terms of

COD there were no significant differences between the unplanted and the Phragmites SSCW.

For BOD5 there were differences between Phragmites SCCW and the other units. In the case

of N-NH4+, although Phragmites SSCW showed the highest average removal, there were no

significant differences amongst the SSCW systems. Finally, for P-PO4-3

there were

significant differences between the Phragmites (highest average) and the Heliconia SSCW

units. Table 3. Summary of average removal efficiencies (%) in each SSCW unit during each treatment.

Parameter Heliconia sp. Sin vegetación Phragmites sp.

1 2 3 1 2 3 1 2 3

DQO 65.98

(11.18)

71.50

(24.73)

53.25

(17.52)

63.36

(19.66)

65.01

(5.90)

81.24

(17.27)

85.90

(12.87)

53.01

(20.93)

73.07

(9.42)

DBO5 71.19

(9.5)

75.53

(6.41)

57.91

(13.68)

72.58

(10.07)

68.48

(5.17)

74.42

(5.66)

87.63

(4.15)

75.52

(11.46)

73.81

(6.82)

N-NH4+ 29.60

(13.49)

6.02

(19.38)

8.18

(18.12)

9.61

(19.10)

11.19

(14.96)

9.96

(31.57)

43.40

(21.21)

33.56

(25.30)

33.16

(10.31)

P-PO43-

14.69

(45.59)

–331.60

(401.28)

-238.11

(294.96)

18.29

(40.09)

-750.21

(186.26)

-2.82

(47.44)

10.49

(84.01)

30.72

(31.93)

-545.56

(157.47)

The results gathered suggest important effects on the performance of the SSCW primarily

related to hydraulic loading rates and its concomitant relationship to plant presence and

species. Additionally, previous data (not shown here) also suggest that as operating time

increases both the rhizospheric and plant developments gradually turn the hydraulic regime of

the SSCW from an arbitrary pattern into a CSTR reactor (Ascuntar et al., 2009). This has

important implications for substrate distribution and contact with biomass, and hence removal

efficiencies, as the SSCW moves into maturity.

Last but no least, the more stable environmental conditions in the tropics (i.e.,

photoperiod, temperature, and energy flows) may play a more important role in the ecology

of the SSCW and thus biodiversity, function and performance of the biota may shift to higher

metabolic rates as a result.

REFERENCES D. Ascuntar-Ríos, A.F. Toro Vélez, M.R. Peña. & C.A. Madera Parra. (2009). Changes of flow patterns in a

horizontal subsurface flow constructed wetland treating domestic wastewater in tropical regions. Ecol. Eng. 35,

274-280.


332

The Effects of Salinity on Reeds (Phargmites australis) in the

Treatment of High Salinity Landfill-Leachates using Horizontal

Subsurface Flow Constructed Wetlands (PO.13)

Tokuo YANO Mika OKANUMA, Yoshiki KUMAGAI, Kazuaki SATO, Akiko

INOUE-KOHAMA and Keijiro ENARI

Department of Environmental Information Engineering, Tohoku Institute of Technology

35-1 Yagiyama-kasumicho Taihaku-ku, Sendai , 982-8577, Japan (E-mail: yano-

[email protected])

INTRODUCTION

Various kinds of plants are planted in the constructed wetlands. There are several roles of

the wetland plants on the constructed wetlands (Brix, 1977). One of the most important roles

of the wetland plants is evapotranspiration, especially in the horizontal subsurface flow

constructed wetlands. Evapotranspiration in the constructed wetland has a close relationship

to water budget, and it influences both the HRT (Hydraulic Retention Time) and the

purification process (Rozkosny et al., 2006). In Japan, most landfill-leachates contain a

salinity which is higher than that of sea water. Although the high salinity remarkably impedes

the growth of many plants, it is thought that reeds can tolerate a high degree of salinity.

Unfortunately, there is little information concerning the growth characteristic of reeds in the

treatment of high salinity landfill-leachates in constructed wetlands. The objective of this

study was to investigate the effect of salinity on reeds under high salinity conditions in the

treatment of a high salinity landfill-leachate using a horizontal subsurface flow constructed

wetland.

METHODS

The pilot-scale horizontal subsurface flow constructed wetlands were located in the

Miyagi prefecture of Japan. The experimental approaches consisted of three runs: Run A was

a raw leachate with reeds, Run B was a double-diluted leachate with reeds and Run C was a

double-diluted leachate without reeds The three pilot-scale constructed wetlands were

identical in size and construction (2m long × 1m wide with a 0.55m water depth). Inflow,

outflow and precipitation were measured in order to evaluate the water budget of the

constructed wetlands.

The flow rate was 55 L/day, giving a theoretical HRT of 10 days. Five sampling wells

which were constructed to enable water extraction from the upper, middle and lower layers of

the water column were placed at equal intervals between the inlet and outlet devices.

The measured parameters were pH, air temperature, EC (Electrical Conductivity), BOD,

COD, T-N, NH4-N and Chloride. The air temperature every 30 min and the amount of daily

precipitation were measured. An investigation of reed vegetation (shoot lengths and shoot

numbers) was completed twice a month. The experimental period was from April, 2010 to

December, 2012.

RESULTS AND DISCUSIONS

The salinity in the constructed wetlands was evaluated. The average salinity of the Run A

inflow was 19.3 g･Cl-/L and that of the Run B inflow was 10.5 g･Cl

-/L during the

experimental periods. The Run B inflow salinity was doubly diluted compared to that of Run

A. The salinity of the inside of the Run A constructed wetland was varied between the ranges


333

of 4.7 to 20.0 g･Cl-/L, with the average being 14.8 g･Cl

-/L, and that of Run B varied between

the ranges of 5.4 to 13.5 g･Cl-/L, with the average being 9.3 g･Cl

-/L. High precipitation

reduced the salinity of the inside of the constructed wetlands. It is reported that the salinity of

the survival limit of reed is within the range of 12-15g･Cl-/L(Barr and Robinson, 1994).

In this study, the obtained results indicated that the salinity of the inside of the constructed

wetlands of Run A and Run B were 14.8 g･Cl-/L and 9.3 g･Cl

-/L, respectively. It seemed that

it was difficult for reeds to grow or survive in both runs under the high salinity conditions.

Table1 shows the growth change

of the shoot lengths and the shoot

numbers from Run A and Run B in

2010, 2011 and 2012. As shown in

the table, the growth of the reeds

from Run A and Run B increased

year-by-year, and vegetation of Run

B was much better than Run A. The average salinity of the inside of Run A was 14.8g Cl-/L

which was in the range of a survival limit of salinity of reed. However, the Run A reeds

remained alive for three years. On the other hand, although the salinity of the inside of Run B

was 9.3 g･Cl-/L, which was in the vicinity of 12g Cl

-/L, the vegetation of Run B was quite

well. High precipitation reduced the salinity of the inside of both Run A and Run B

constructed wetlands, and the drastic change in salinity caused by high precipitation might

enable the reed to survive.

The coefficient of correlation (R2) of salinity to the RGR (Relative Growth Rate) of the

shoot extension was 0.5789 and that of the shoot increase was 0.0391 in the vegetation

periods from April to June. The influence of salinity was different in both shoot extension and

the shoot increase in the early stage of the vegetation periods.

The water budget showed that the ratio of evapotranspiration to total-inflow was 0.74 by

Run B, 0.27 by Run A and 0.19 by Run C. The water loss by the evapotranspiration in Run B

was much more than in Run A and Run C. The load reduction efficiencies of COD, BOD, T-

N, NH4-N of Run B were much higher than those of Run A and Run C.

CONCLUSIONS

・The salinity of the inside of the Run A constructed wetland was 14.8g Cl-/L and that of

Run B was 9.3g Cl-/L. Although, the growth of Run A reed was impeded remarkably

compared to Run B under the salinity conditions, the vegetation of reed from both runs

increased year- by- year.

・The influence of salinity was different in both shoot extension and the shoot increase in the

early stage of the vegetation periods. It was suggested that the growth characteristic of the

reeds might be different in the shoot extension and the shoot increase.

・The dense bed of vegetation provided a high rate of evapotranspiration and the loss of

water, which made great contributions to reduce the pollutant load.

REFERENCES Barr M.J.and Robinson H. D. (1994) Constructed wetlands for landfill leachate treatment, Waste Management &

Research, 17, 498-504.

Brix H. (1997) Macrophytes play a role in constructed wetlands?, Wat.Sci.Tec., 35(5), 11-17.

Rozkosny M., et al. (2006) Water Balance of the Constructed Wetlands-A Study of

the macrophytes evapotranspiration, Proceeding of 10th

International

Conference on Wetland Systems for Pollution Control, 123-129, Lisbon,

Portugal

Table 1. G rowth change of reed for 3 years2010 2011 2012

Run A 65.2 83.2 96.3Run B 111.5 172.4 222.2Run A 16.5 49.5 139Run B 108 420 556

shootLengths(cm )

shoot

num bers(m-2)


334

COD, TKN, NH4+ and NO3

- removal in polyculture constructed

wetlands at pilot scale treating landfill leachate (PO.75)

A.C. Cortes-Sandovala, C.A. Madera-Parra

a, M.R. Peña-V

b, E.J, Peña-S

c

aUniversidad del Valle, EIDENAR School, AA 25360, Cali, Colombia

bUniversidad del Valle, Cinara Institute, AA 25360, Cali, Colombia

c Universidad del Valle, Biology Department, AA 25360, Cali, Colombia

([email protected]; [email protected];

[email protected], enrique.peñ[email protected])

INTRODUCTION

Sanitary landfills are still the most widely used method for solid waste disposal around the

world, and they release a wide range of chemical compounds due to waste degradation along

their entire life cycle. Landfill leachate (LL) may contain large amounts of organic matter,

both biodegradable and refractory, as well as considerable ammonia-nitrogen, heavy metals,

chlorinated organics and inorganic salts. The discharge of untreated LL into surface and

ground waters is a common problem in many developing countries. Therefore, there is a clear

need for cost-effective and reliable technologies for LL treatment. Thus, Constructed

Wetlands (CW), have been recently reported to having a high potential in this respect.

However, experiences up to now are mostly limited to developed countries with seasonal or

temperate climates and using mainly cosmopolitan plants. Therefore, the aim of this research

was to study the performance of COD, TKN, NH4 and NO3 removal from LL using pilot-

scale Sub Surface Constructed Wetlands (SSCW) planted with polyculture varieties of the

tropical native plants Gynerium sagittatum (Gs), Colocasia esculenta (Ce) and Heliconia

psittacorum (He).

MATERIALS AND METHODS

The experiment was carried out during six months in the Presidente regional landfill (3º

56`01.54” N y 76º 26`26.05”O) at San Pedro village, in southwest Colombia. Four sub-

surface CW tanks units (7.80 x 2.30 x 0.60 m in length, width and depth, respectively), were

fitted and run in parallel. Each tank was filled out to a depth of 0.50m with gravel (φ=25 mm

and porosity (η)=40%). Three bioreactors were divided into three equal sections, each one 2.6

x 2.3 m in length and width, respectively. At each section of one SSCW unit, 36 healthy

cuttings (0,10-0,15 m height) of one single species were placed in a chosen order.

Meanwhile, in the other CW unit, 36 cuttings of each species were randomly planted

throughout the whole length of unit, setting in all CW a equivalent average plant densidity of

6 transplants or cuttings m-2

. Both, experimental units and plants allocation in the setting

were randomly done. The final distribution of plant species in the bioreactors were: CW1

(He-Ce-Gs); CW2 (randomly), CW3 (Ce-Gs-He), CW4 (Gs-He-Ce). The SSCW were daily

fed by gravity under continuous regime (24 hr d-1

) with a water inflow of 0,5 m3 d

-1 each,

and the theoretical HRT was set at 7 d. All CW received the effluent from a high-rate

anaerobic pond (BLAAT®). The influent and effluent from each reactor were analyzed for

COD, DTOC, TKN, NH4+ and NO3

- weekly, and BOD5 monthly according with APHA

(2005). Temperature, pH, ORP, EC and DO were measured twice a week.


Table 1 shows the average figures of parameters monitored during the study. The pH in

the inlet and outlet was alkaline, but no differences between units were observed. The

temperature ranged between 26 and 27 ºC, keeping mesophilic conditions for the

development of biological processes in the liquid-solid matrix. DO values in the SSCW




335

effluents were a least 5-fold higher when compared to the influent. This suggests the plants

influence on the oxygen balance in the water column. Meanwhile, EC did not show

significant differences between units. The ORP reached negative values after the first week

(figures ranging between -30 and -7 mV), thus, indicating the onset of a weak anoxic

condition in the rizosphere. This was probably caused by the production of organic exudates

jointly with the alternation of dark-light process that switch between photosynthesis and

respiration, which also affect the DO balance. In relation with COD, DTOC and BOD5, the

removal efficiencies were relative good with higher performances in SSCW4 for all

parameters (50%). However, there were no differences between SSCWs. The BOD5 /COD

ratio was below 0,3 indicates that the available organics are difficult to degrade by

microorganisms (Tanveer Saeed, 2012), and almost 80% of the COD was under soluble

form, thus, indicating mostly the predominance of refractory organic matter.

In general, all SSCWs showed good removal efficiencies for all parameters with higher

performance in CW4 (Table 1). Nitrate removal for CW1 to 3, was low, effluent of CWs was

higher than influents, indicating that are being subserved by the nitrification process and

doubtless, the ammonium is transformed into nitrate ion. Likewise, according with COD and

BOD data, the LL do not have enough biodegradable carbon source and an external organic

source to carry out heterotrophic denitrification, this may be contributing with the high NO3- -

N values in the effluent. Table 1. Averages results of physical-chemical parameters monitored on CW`s reactors.

Parameters Influent CW1 CW2 CW3 CW4

mean SD Mean SD Mean SD Mean SD Mean SD

COD total (mg L-1

)* 681,0 187,7 409,0 147,1 441,4 112,8 426,2 124,8 384,7 120,6

COD filtered (mg L-1

)* 546,3 117,2 318,2 142,4 340,1 112,0 331,7 119,1 288,6 102,2

TOC dissolved (mg L-1

)* 253,4 81,2 169,3 62,5 189,3 85,2 168,0 67,3 145,4 63,1

BOD5 (mg L-1

)** 151,7 94,5 70 10 46,7 11,5 63,3 25,2 60,0 45,8

TKN (mg L-1

)* 286,7 88,4 204,4 53,6 194,8 45,3 181,6 51,1 164,5 60,3

NH4+

-N(mg L-1

)* 214,8 70,0 140,1 45,0 142,3 47,1 119,1 43,0 97,1 54,2

NO3−

-N(mg L-1

)* 13,1 18,5 12,8 12,0 13,1 12,5 13,8 14,6 11,1 11,0

pH+ 7,8-8,4 0,1 7,9 0,2 7,9 0,2 7,9 0,2 7,7 0,2

Temperature (oC)+ 28,1 1,7 26,3 1,9 26,3 1,6 26,9 1,8 26,4 1,8

EC (dS m-1

)+ 5,2 0,9 3,7 0,9 3,67 0,9 3,6 0,9 2,9 1,1

DO (mg L-1

)++ 0.5 0,3 3,8 1,5 2,9 0,8 4,7 4,2 4,9 4,2

ORP (mV)+++ -22,6 106,0 -10,8 90,2 -8,5 93,8 -6,2 91,2 13,3 76,0

(*: N=26. **: **: N= 10. +: N=18. ++: N=14. +++: N=11)

Regarding with TKN and NH4+-N, all CWs shows good performance with an avarege

removal eficienciy of 43 and 53%; 43 and 61% espectively, but effluent from CW4 presented

the higher removal capacity. The decrease of N species in SSCWs migh also be a

consequence of microbial interactions with nitrogen, sedimentation, chemical adsorption,

and plant uptake as a pointed out by Chang-gyun et al., (2009).

The results indicate that the polyculture CW with tropical plants can be used for treat of

LL with good removal potentials for COD, DTOC, BOD5, TKN, NO3, NH4+. SSCW4 showed

the best behaviour indicating that distribution of the plants within the reactor can positively

influence the performance of CW.

CONCLUSIONS

This work showed that SSCWs planted with polyculture of tropical plants are able to treat

leachate with good removal efficiencies (between 42 to 70%) for COD, BOD, DTOC, TKN,

NH4+ and NO3


336

Effect of water level variation in the removal of pathogens and

nitrogen in vertical subsurface flow constructed wetlands to treat

domestic wastewater under tropical conditions. (PO.124)

Marcela Gonzáleza, Diego Paredes

a, Carlos A. Arias

b

a Water and Sanitation Research Group, Universidad Tecnológica de Pereira, A.A. 97,

Pereira, Colombia. ([email protected] – [email protected])

b Plant Biology, Department of Biological Sciences, Aarhus University, Aarhus, Denmark,

([email protected])

INTRODUCTION

Vertical subsurface flow constructed wetlands have been used exclusively in the treatment

of nitrogen, due them posses a higher ability to oxidize the ammonia nitrogen (Vymazal,

2007) if are compared with horizontal subsurface flow constructed wetlands. That ability has

prompted the use of vertical flow constructed wetlands in the treatment of wastewater with

high contents of nitrogen (Stefanakis y Tsihrintzis, 2012). The effectiveness of treatment in a

vertical flow constructed wetland depend mainly on design and operating variables, such as

hydraulic load, filter material, source and quality of the wastewater and plant species

associated to the system (Kadlec y Wallace, 2009). A successful treatment depends, greatly

on an adequate hydraulic load and a correct waste water supply. Likewise, the aeration of the

wetland bed is related with the performance of the system, which can be induced by

intermittent loads for re-establishment of aerobic conditions or forced aeration (Stefanakis y

Tsihrintzis, 2012). To maximize the efficiency of nitrogen removal in vertical flow

constructed wetlands, it is necessary to increase the aeration by means of oxygen transfer that

is why it becomes necessary to evaluate the effect of variation of domestic wastewater level

over the nitrogen and pathogen removal efficiency in subsurface flow constructed wetlands.

METHODS

In order to evaluate the nitrogen removal efficiency (ammonia nitrogen, nitrites and

nitrates) and pathogens (Total and Fecal Coliforms) in vertical flow constructed wetlands, it

was used as unique factor the level of domestic wastewater inside the filter media, being

monitored at three different depths (0 – 40 – 65 cm), due to water level in a wetland can

increase or reduce the aeration inside the filter media, hence interfering in the pollutant

reduction. The configuration of the assessed wetlands, consisted on two concrete-made units

(5 m width, 8.65 m length and 0.80 m depth), whose superficial area was 43.3 m2 each, which

contained middle and coarse gravel as filter media and were planted with papyrus (Cyperus

sp.). The water flow of each wetland was supplied by means of an automatic pumping

system.

The vertical flow constructed wetlands were evaluated under three scenarios. In the first

scenario, one of the experimental units was operated with 0 cm of water level (without

accumulation of wastewater inside the filter media) – VSSF1 and the other was operated with

65 cm of water level, both of them supplied with an average influent of 314 Lh-1

; in the

second scenario it was maintained the same wetland configuration but it was presented an

influent reduction, whit an average value of 202 Lh-1

; and finally in the third scenario both

wetlands were operated with the same conditions, it means with a water level of 40 cm each

and an average influent of 255 Lh-1

. The water flow treated by the vertical flow constructed

wetlands came from the wastewater treatment plant of a manufacturer of electrical

transformers, located in coffee region of Colombia.



337

The performance of the constructed wetlands were monitored taking weekly grab samples

in the influent and effluent of each unit for the subsequent determination in laboratory of

bacteriological parameters such as total coliforms and E. Coli (membrane filtration method of

Standard Methods APHA, 2005), organic matter (BOD5, COD, TSS) and nutrients (Standard

Methods APHA, 2005). The statistical analysis of the obtained data was executed by means

of application of a variance analysis (ANOVA), comparing the means found in the analyzed

parameters in each wetland and for that it was used the statistical package SPPS version 19.


In Figures 1, 2 and 3 are presented the removal percentages achieved for total coliforms,

E. Coli and total nitrogen (measured as ammonia nitrogen, nitrites and nitrates). The lowest

concentrations of total coliforms at the effluent were found at 40 cm of water level, removing

between 1.4 and 1.6 log units. Likewise occurred for E. Coli, were the wetlands with a water

level of 40 cm showed removal values between 1.1 and 1.2 log units, being them superior to

those achieved with water levels of 0 cm and 65 cm. The ANOVA analysis applied for

bacteriological parameters determined that exist significant differences (p<0.05) for removal

of total coliforms and E. Coli, indicating that at 40 cm of water level in the filter media

presented the lowest concentrations at the effluent for bacteriological parameters. Some

researches have found that the removal efficiency of E.Coli is around 2 log units in vertical

subsurface flow systems (Molleda et al., 2008; Reinoso et al., 2008), being that type of

wetland effective for pathogen removal, such as indicator organisms of the presence of

intestinal parasites of human origin (Reinoso et al., 2008).

Figure 1. % coliforms mean removal in

influent and effluent per VSSF Figure 2. % E. coli mean removal in

influent and effluent per VSSF Figure 3. % Total nitrogen mean removal in

influent and effluent per VSSF

In general, constructed wetlands at 0, 40 and 65 cm, achieved a removal rate of organic

matter close to 50% for COD and TSS (18 and 3 g/m2d of removed load, respectively).

Regarding to BOD5, it was obtained an average removal rate of 60% that corresponded to a

load reduction of 6 g/m2d. The variance analysis of the organic matter removal did not show

significant differences between the results obtained with the different water levels (p>0.05).

The VSSF1 with 0 cm of water level in the first and second scenario removed the highest

ammonia nitrogen load (between 10 and 13 g/m2d). The vertical wetlands with water levels

of 40 and 65 cm shown average reductions between 6 and 5 g/m2d of ammonia nitrogen.

With respect to total nitrogen, the wetlands presented a removal rate between 6 and 5 g/m2d.

The variance analysis (ANOVA) for this parameter concluded that exist significant

differences (p<0.05) for removal of total nitrogen, at different water levels in the filter media.

Some researches indicate that the percentage of load reduction in vertical systems in terms of

TSS and COD can be higher than 90%, whereas for ammonia nitrogen can be reached a

reduction of 90% (Langergraber et al., 2009; Prochaska y Zouboulis, 2009).


338

The results of this research show that the design and operating parameters such as

hydraulic load and influent concentration are factors that affect the performance of a vertical

wetland, which is reflected in the reduction of ammonia nitrogen, finding a strong difference

between the water levels of 0 cm and 40 – 60 cm, possibly due to a higher oxygen

transference of oxygen at 0 cm. In pathogen organisms, the wetlands had a similar behavior,

reaching removal values close to 2 log units. It is necessary to optimize the aeration in the

vertical wetlands from operating parameter such as hydraulic load.

CONCLUSIONS

The behavior of a vertical system depends largely on design and operating parameter. The

hydraulic load and quality of the wastewater to treat are factors that influenced the efficiency

of ammonia nitrogen removal, since it was an incidence of the oxygen transfer in each

operating scenario. For microbiological parameter, there was a significant effect in the

variation of water level, while for removal of organic matter there were no significant

differences in the applied treatments. It can be said that when a lower accumulation of

wastewater exist, based on a level of 0 cm can be promoted the aeration of the vertical

wetland bed, easing the aerobic processes such as nitrification.

REFERENCES APHA, (2005). Standard methods for the examination of water and wastewater, 21

st Edition.

Langergraber, G., Lerunch, K., Pressl, A., Sleytr, K., Rohrhofer, R., Haberl, R., 2009. High – Rate Nitrogen

Removal in a Two Stage Subsurface Vertical Flow Constructed Wetland. Desalination 246, 55 – 68.

Kadlec, R.K., Wallace, S.D. (2009). Treatment Wetlands, Second Edition, CRC Press, Taylor & Francis Group,

New York.

Molleda, P., Blanco, I., Ansola, G. and De Luis, E., (2008) Removal of wastewater pathogen indicators in a

constructed wetland in Leon, Spain. Ecological Engineering 33 (3-4): 252 – 257.

Prochaska, C.A., Zouboulis, A.I. (2009). Treatment performance variation at different depths within vertical-

flow experimentel wetlands fed with simulated domestic sewage. Desalination 237, 367 – 377.

Stefanakis, A.I., Tsihrintzis, V.A. (2012). Effects of Loading, Resting Period, Temperature, Porous Media,

Vegetation and Aeration on Performance of Pilot-Scale Vertical Flow Constructed Wetlands. Chemical

Engineering Journal 181 – 182, 416 – 430.

Reinoso, R., Torres, L.A., Bécares, E. (2008). Efficiency of natural systems for removal bacteria and pathogenic

parasites from wastewater. Science of the Total Environment 395, 80 – 86.

Vymazal, J., 2007. Removal Nutrients in Various Types of Constructed Wetlands. Science of the Total

Environment, 380, 48 – 65.


339

What Design Requirements for an Efficient Removal of Total

Nitrogen by Constructed Wetlands? (P.156)

Y. MILLOTa,d

, P. MOLLEb, S. TROESCH

a, D. ESSER

c, D. ROUSSEAU

d

aEpur Nature, 12 rue Toussaint Fléchaire, Caumont-sur-Durance, 84510, FRANCE

([email protected] - [email protected]) bIRSTEA (formerly Cemagref), 5 rue de la Doua, Villeurbanne, 69626, FRANCE

([email protected]) cSINT, La Chapelle du Mont du Chat, 73370, FRANCE, ([email protected])

dDepartment of Analytical Chemistry Ghent university, Department of Industrial Biological

Sciences, Graaf Karel de Goedelaan 5, Kortrijk, 8500, BELGIUM

([email protected])

INTRODUCTION

More than 2,500 constructed wetland plants are presently in operation in France and an

average of 150 supplementary units are build every year. The French design consists of two

successive stages of vertical flow filters. While the first stage, dimensioned at 1.2 to 1.5 m²

per P.E., is divided into three parallel cells of VF alternatively fed with raw wastewater for

3.5 days, the second, dimensioned at 0.8 to 1 m² per P.E. is divided into 2 cells alternatively

fed for 1 week. These cycles are capital for treatment (oxygen transfer, mineralization of

surface sludge and biomass control).

This system allows reaching very good removal of organic matter, suspended solids and

Kjeldhal nitrogen (up to 90%, 95% and 85% respectively) (Troesch & Esser, 2012). Higher

hydraulic loads than 0.7 m/d decrease aeration which is detrimental for nitrification (Molle &

Prost-Boucle, 2012). While depth increase positively influences nitrification process in VF

systems, some of designs use filtering material with a high cationic exchange capacity (CEC)

in order to fix ammonia and improve nitrification rate during the aerated rest period.

However, the French system is not suitable when there are discharge constraints on total

nitrogen as it does not provide anoxic conditions for denitrification. This implies the

construction of a complementary treatment unit when total nitrogen removal is needed. This

leads to an increase of surface area requirements. Nevertheless, this design is limited by the

organic carbon available for total denitrification.

The INNOPUR project aims to improve our comprehension of total nitrogen treatment and

to determine the influence of design and operation parameters on treatment performances.

METHODS

The INNOPUR research program is divided into two parts which respectively deal with

nitrification and denitrification knowledge improvement.

Study of nitrification

Six pilots will enable to monitor the effect of different parameters on nitrification. Five

first stage and one second stage VF filters of 2.25m² each, will allow studying different

configurations. These units differ in terms of design (depth of filtration, material with high

CEC, granulometry, intermediate aeration) but also operational modus (standard versus high

load operation, recirculation). Table 1 summarizes the different designs which will be

assessed:


340

Table 1. Summary of vertical flow filter’s design.

Pilot unit Filtration layer Transition layer Drainage layer

VF1G+ Gravel (100cm) - Pebble (15 cm)

BiHo Gravel (50cm) Pebble (15 cm) + aeration Coarse Pebble (50 cm)

VF1Z Gravel + Zeolite (30 cm) - Pebble (15 cm)

VF1S Gravel (30cm) - Pebble (20 cm)

VF1HL Gravel (30cm) Pebble (10 cm) + aeration Coarse Pebble (15 cm)

VF2Z Sand + Zeolite (40cm) Gravel (10 cm) + aeration Pebble (15 cm)

A continuous monitoring of temperature and dissolved oxygen at different depths is

implemented inside each filter in order to assess oxygen consumption during treatment and

the reoxygenation of filter during the rest period. pH, redox and nitrogen (NH4, NO3) will be

continuously monitored (inlet and outlet) in order to gain more insight in the functioning of

the filter during the feeding period. COD, BOD5, TSS and alkalinity will be measured on the

basis of 24h average samples for each pilot. Finally, more intensive measurements will be

punctually done (each day of feeding), including monitoring of removal performances at

different depths for a better understanding of the treatment mechanisms and in order to

develop a simplified modeling tool (See Morvannou et al., 2013). Indeed, as a new necessity

in order to overcome the simple consideration of CW as a “black-box”, several numeric

models have been developed for the last few years (Langergraber et al., 2009).

Study of denitrification

Three pilots will allow monitoring of parameters influencing denitrification. The first

consists of a VF filter with a saturated layer at its bottom while the two others are saturated

second stage VF filters. The latter two filters are filled with different materials (pebbles or

plastic media) in order to assess their influence on performances. Moreover, several heights

of saturated layer, residence times and ratios of organic carbon / nitrate will be assessed. This

will provide knowledge on denitrification kinetics. Each pilot will be monitored with redox

sensors in order to evaluate the denitrification potential.


The pilot units are currently being constructed. No results are available at this point in

time, but the poster presented at WetPol will include first results from the start-up phase.

ACKNOWLEDGEMENTS

We thank everybody who provided help during design and building step of these pilot

units, in particular Philippe Roche, Virginie Buisson, Luc Canavese and Christophe Put.

REFERENCES Langergraber, G., Rousseau, D.P.L., Garcia, J. & Mena, J. (2009). CWM1: a general model to describe

biokinetic processes in subsurface flow constructed wetlands. WaterSci. Technol.. 59 (9):1687-97.

Molle, P., Prost-Boucle, S. (2012). Recirculation on a single stage of vertical flow constructed wetland:

Treatment limits and operation modes. Ecol. Engin.. 43, 81–84

Troesch, S., Esser, D. (2012). Constructed Wetlands for the Treatment of raw Wastewater: the French

Experience. Sustainable Sanitation Pratice. (12):9-15 (www.ecosan.at/SSP)

Morvannou, A., Forquet, N., Troesch, S., Molle, P. (2013). How modeling improves the design of French

vertical flow CW, WetPol, Nantes, FRANCE, October 13 - 17, 2013


341

Selection of Iron and Aluminium Oxyhydroxides based

Adsorbents with Enhanced Phosphorous Adsorption Capacity for

Use in Wetland and Fixed Bed Type Systems (PO.83)

Yoann Glocheuxa, Stephen J. Allen

a and Gavin M. Walker

a,b

aSchool of Chemistry and Chemical Engineering, Queen’s University Belfast, David Keir

Building, Stranmillis Road, Belfast BT9 5AG, UK ([email protected])

bMaterials Surface Science Institute, Department of Chemical and Environmental Sciences,

University of Limerick, National Technological Park, Limerick, Ireland

INTRODUCTION

Nutrients removal is the key step for efficient working processes in wetland systems.

Pollutants removal in wetland systems can be divided into three main processes: plant uptake,

biomass consumption and fixation/adsorption onto substrate. The selection of materials being

used in wetland systems can influence greatly the adsorption efficiency; especially for

phosphorous fixation (Barca et al., 2012; Cucarella and Renman, 2009).

This study focuses on the synthesis of different materials for the adsorption of phosphate

from water. The selection of the best performing material for continuous process is presented.

The best material produced was then tested in removing P in continuous system using the

Rapid Small Scale Column Test technique.

Adsorbent synthesis

Iron, aluminium and mixed iron-aluminium oxides were produced in this study using

industrial grade coagulants. The three different technical grade coagulants used are the

commonly named chemicals ferric, alum and FAS. These three solutions were produced by

Clinty Chemicals, Ballymena NI.

Adsorbent materials were produced by a precipitation process using a concentrated sodium

hydroxide solution (30 % w/w). Part of the resulting powder was post-washed in distilled

water to remove any remaining weakly-bonded chemical surface groups. The materials were

named as a function of the metal solution used, pH at equilibrium in the synthesis process and

the presence of pre-washing and post-washing process (ex: Alum-Y-Y-10).

Batch and dynamic P removal studies

The phosphate removal capacity of the materials produced was investigated in adsorption

experimental studies. A first a screening study was carried out in order to select most efficient

materials. Concentration studies of best performing materials were then performed. All

experiments were carried out at pH 7; adsorbent dosage ratio was 1 g.L-1

and starting

phosphorus concentration in screening experiments was 100 ppm. Adsorbent particle size

range was 180-100 µm. Distilled water was used in experiments, NaH2PO4.2H2O was used as

the phosphorus source, 100 mg.L-1

of NaHCO3 and 2 mM of BES was used as pH buffer.

Equilibrium time is 48 hr. Column studies were carried out using 355-500 µm particle size of

the most efficient material produced based on a scaled down approach of wetland system.

This approach allowed a fast breakthrough of the dynamic system. Experimental set up is

presented in Figure 2 a. Phosphorous measurements were carried out by ICP-AES.


Figure 1 a presents the results from the screening experiments while Figure 1 b shows the

isotherms of the 3 most efficient materials selected. Figure 2 b shows the results of the

column study. Key results are listed below.


342

Figure 3 Screening experiments of Al and Fe oxyhydroxides produced at different pH and post-washed

(b) isotherm of 3 selected adsorbents

1) Higher P removal performances of materials produced using ferric and increase of P

removal in function of synthesis pH of materials

2) Washing process can remove chemical surface groups; thus reducing PRC

3) Ferric ¼-Y-Y-10 showed a PRC of 22.34 mg.g-1

at 10 ppm in batch

Figure 4 Experimental set-up for column study (a) and results of columns run with Ferric ¼-Y-Y-10 at

different Empty Bed Contact Time treating a P solution of 10 ppm (b)

CONCLUSIONS AND FUTURE WORK

Materials produced have shown a P removal capacity of 7.05 to 19.01 mg P.g-1

in column

studies. This gives a prediction of similar performance for a continuous system using larger

particle size (10-25 mm), similar Hydraulic Loading Rate (600 - 1200 L.m2.d

-1) and higher

Empty Bed Contact Time (24 h). Full scale system is under investigation.

ACKNOWLEDGEMENTS

EU Framework 7 project “ATWARM” (Marie Curie ITN, No. 238273)

REFERENCES Barca, C., Gérente, C., Meyer, D., Chazarenc, F., Andrès, Y., 2012. Phosphate removal from synthetic and real

wastewater using steel slags produced in Europe. Water Res. 46, 2376–2384.

Cucarella, V., Renman, G., 2009. Phosphorus Sorption Capacity of Filter Materials Used for On-site

Wastewater Treatment Determined in Batch Experiments–A Comparative Study. J. Environ. Qual. 38, 381.

pH synthesis

4 6 8 10 12

qe in

mg P

.g-1

0

10

20

30

40

50

60

Alum oxides washed

FAS oxides washed

Ferric 1/4 oxides washed

Ce in ppm

0 20 40 60 80

qe in m

g P

.g-1

0

10

20

30

40

50

60

Alum-Y-Y-10

FAS-Y-Y-4

Ferric 1/4-Y-Y-10

Langmuir models

Freundlich models

Volume in mL

0 10000 20000 30000 40000

Ct/C

0

0.0

0.2

0.4

0.6

0.8

1.0

EBCT is 1.5 min

EBCT is 3 min

EBCT is 6 min

Inlet P concentration

Inlet standard deviation

Rational model

BDST model weighted by y-2

FC

T

50 L tank

GF

GB

SorbentPP

Waste

GB: Glass BeadsGF: Glass FritPP: Peristaltic PumpT: Electronic Timer3-WV: 3 Ways ValveFC: Fraction Collector

3-WV


343

Phosphorus retention and sediment resuspension in constructed

wetlands – a method comparison. (PO.123)

Pia Kynkäänniemia, Karin Johannesson

b, Barbro Ulén

a & Karin Tonderski

b

a

Swedish University of Agricultural Sciences, Department of Soil and Environment, P.O.

Box 7014, SE-750 07 Uppsala, Sweden. ([email protected]) bLinköping University, Department of Physics, Chemistry and Biology, SE-581 83

Linköping, Sweden.

INTRODUCTION

Three wetlands (Bergaholm, Skilleby and Wiggeby) constructed in agricultural

catchments in central Sweden were investigated for their function as sediment and

phosphorus (P) traps. The wetlands had similar area (0.06-0.08 ha) but varied in shape and in

relative size to catchment area (0.05-0.32 %). Sedimentation of particles and associated P has

been shown to be the main retention process in wetlands that receive high load of particulate

P. The aim was to compare two methods of estimating particle and P retention; I) inflow-

outflow balances and II) P in accumulated sediment. In addition resuspension of accreted

sediment was investigated.

METHODS

Water flow was measured and water samples were taken at each wetlands inlet and outlet.

Sedimentation on plates that represented net sedimentation was sampled ones a year and

sedimentation in traps (gross sedimentation) three or four times a year. Particle and P

retention was estimated for Aug 2010 - Aug 2012.


The hydraulic load and sedimentation varied between wetlands and years. Average

particle retention based on inflow-outflow balances were approximately 80, 150 and 50 tons

ha-1

yr-1

in Bergaholm, Skilleby and Wiggeby respectively, while the particle retention based

on accumulated sediment was lower approximately 50, 20 and 10 tons ha-1

yr-1

. Net

sedimentation increased with increasing gross sedimentation. Between 70 and 89 % of the

sediment was resuspended in these small wetlands. The estimation of average P retention was

more similar with the two methods; P net balance from water sampling (approximately 80,

60, 10 kg ha-1

yr-1

) and sediment plates (approximately 70, 20 and 10 kg ha-1

yr-1

).

This paper will provide useful information, pros and cons, for choosing monitoring

method for constructed wetlands.


344

Sulfur amount and distribution in the soil-matrix of a pilot-scale

horizontal subsurface flow constructed wetland (PO.25)

Rania A. B. Saada, Peter Kuschk

a, Heinz Köser

b

aDepartment of Environmental Biotechnology, Helmholtz Centre for Environmental Research

– UFZ, Permoserstraße 15, Leipzig, D-04318, GERMANY ([email protected] -

[email protected])

bDepartment of Environmental Engineering, Martin-Luther-University Halle-Wittenberg,

Geusaerstraße 135, Merseburg, D-06217, GERMANY ([email protected])

INTRODUCTION

The bigger part of the research on the inorganic sulfur transformations in horizontal

subsurface flow constructed wetlands (HSSF CWs), limited as it is, was conducted by

analyzing the pools of sulfur in the pore-water (e.g. Wießner et al., 2010). Therefore, it was

relevant and interesting to investigate the inorganic sulfur pools in the soil-matrices of these

systems, to augment our understanding of the sulfur transformation processes, and their

significance.

We conducted soil sampling in a HSSF CW, for which the results for pore-water

parameters were available for ~ the last 10 years.

METHODS

The pilot-scale research facility was situated in Bitterfeld in the state of Saxony-Anhalt,

Germany; and contained four CW beds. The investigated HSSF CW was planted with

Phragmites australis and received high-sulfate-containing contaminated ground water. The

main influent contaminants were: monochlorobenzene (mean conc. 12 mg/L); sulfate (900

mg/L); and ammonia (50 mg/L).

Triplicate soil core samples (width-wise) were taken from the HSSF bed at distances: 0.5,

1.0, 2.0, 3.0, 4.0 & 6.0 m from inflow (total number of soil cores: 18), using a 10 cm

diameter, 40 cm deep stainless steel cylinder. Each core was sliced depth-wise to up to 4

segments ~10 cm each. The soil samples were immediately placed in sealable plastic bags

with air extruded, and maintained in dry ice in the dark until delivery to the laboratory, where

it was stored at -20°C until further analysis. All sample take and pre-handling was performed

according to University of Queensland (2004).

Prior to analysis, the samples were dried at 105°C to a constant weight, and the plant root

material was separated manually. The soil material (sand and fine gravel) was sieved, and

the fraction < 200 µm was analyzed using X-ray fluorescence (XRF) for sulfur, iron and

other relevant elements.


Previous investigation of the sulfur transformations in the pore-water of the same HSSF

CW (Wu et al., 2011) reveled that sulfur transformations (sulfate reduction and sulfide

oxidation processes) took place in this bed; and they calculated 70% of the reduced sulfate as

disappeared from the pore-water (the difference in the balance between the removed sulfate-

sulfur and the sum of detected sulfide and elemental sulfur). Following their findings, it was

hypothesized that this sulfur missing from the sulfur balance was to the bigger extent

immobilized in the soil-matrix and to lower extent volatized as hydrogen sulfide.

Contrary to our hypothesis, we found no sulfur accumulation in the soil-matrix. In

general, the sulfur in all the samples was much less than the control sample (of the pristine

soil that was kept intact and was available for analysis); see Fig. 1.


345

In addition, the sulfur did not show high spatial variation, and seemed to have reached

some sort of steady-state concentration in the soil. However, it is important to conduct sulfur

speciation, as there may be spatial distribution of the different sulfur species. Currently,

separation of chromium reducible sulfur, elemental sulfur and acid-extractable sulfate-sulfur

is being conducted.

As plant matter distribution clearly correlated with the depth (the samples of higher depths

contained much more plant root material that the lower depths; data not shown), it is

estimated that the distribution of oxidized vs. reduced sulfur species also correlates with

depth, and that the higher depths contain more oxidized species, while the lower depths

contain more reduced sulfur species, due to the rhizoshperic effect. This hypothesis will be

tested by means of sulfur speciation. It should be considered however, that the plant matter

distribution alone does not conclusively describe the regions affected by the rhizosphere.

Fig. 1. Concentration of sulfur in the control (pristine soil; horizontal dotted line) and the different depth

fractions (see legend) of one of the triplicate sets of the soil samples

CONCLUSIONS

Sulfur was not found to be accumulating in the soil-matrix, and did not show significant

spatial variations. It is important to conduct sulfur speciation, to elaborate on the distribution

of the different sulfur species. It is also relevant to investigate the other processes that

assemble the fate of sulfur in constructed wetlands (e.g. volatilization, plant uptake, etc.) in

addition to pore-water and soil-matrix processes; in order to have an overall understanding of

the sulfur transformations in CWs.

ACKNOWLEDGEMENTS

This research was sponsored by the German Federal Ministry of Education and Research

‘BMBF’, International Bureau, IPSWaT program; the Helmholtz Centre for Environmental

Research – UFZ; and the Helmholtz Interdisciplinary Graduate School ‘HIGRADE’.

REFERENCES University of Queensland (2004): Acid sulfate soils laboratory methods guidelines, version 2.1

Wießner, A, Rahman, K. Z., Kuschk, P, Kästner, M, Jechorek, M (2010): Dynamics of sulphur compounds in

horizontal sub-surface flow laboratory-scale constructed wetlands treating artificial sewage. Water Research 44:

6175-6185

Wu, S, Jeschke, C, Dong, R, Paschke, H, Kuschk, P, Knöller, K (2011): Sulfur transformations in pilot-scale

constructed wetland treating high sulfate-containing contaminated groundwater: A stable isotope assessment.

Water Research 45: 6688-6698

0

2

4

6

8

10

12

14

0 1 2 3 4 5 6

Distance from inflow (m)

g s

ulf

ur/

kg

dry

so

il

0-10 cm

10-20 cm

20-30 cm

30-40 cm

Control


346

Modeling of Phosphorus Transformation and Removal in

Constructed Wetland: Case of Constructed Wetland in

Gaborone, Botswana (PO.33)

Richard J. Kimwagaa and Baboloki Autlwetse

b

aUniversity of Dar es Salaam, Water Resources Engineering Department, P. O. Box 35131,

Dar es Salaam, Tanzania ([email protected] and [email protected]) bDepartment of Water Affairs, Gaborone, Botswana

INTRODUCTION

Department of Water Affairs (DWA) of Botswana has piloted a constructed wetland to

treat its wastewater in order to demonstrate how low cost technologies can be used to treat

wastewater. All the wastewater from the DWA offices is collected into a septic tank and from

there it flows into the constructed wetland for treatment.

Constructed Wetlands (CW) have been used to treat raw sewage the world over and

different components of it have been studied, now this study focused on the removal of

phosphorus simply because the larger component of the wastewater produced in DWA is

from the restrooms, cleaning of the floors and washing machinery in mechanical workshops

using chemicals which might contain phosphates that are eventually released into the

environment and end up causing eutrophication.

Since no research has been carried out on the processes taking place of DWACW, it is in

this regard that this study was carried out to study the transformation and removal processes

for phosphorus removal taking place in Constructed wetlands through modeling.

METHODS

Study Site Characteristics, Wastewater Sampling and Analysis

The Constructed Wetland under study was in Gaborone, Botswana within the Department

of Water Affairs treating wastewater generated by about 1000 employees from restrooms,

cleaning the floors and washing the machinery. All the wastewater is collected into a septic

tank and flow into each of the cells for treatment.

The size of the cells was designed and constructed with the theory of plug flow in the

mind. The dimensions of each cell in the DWACW are: Length, L =25m, Width, W = 4m,

Media depth (m) = 0.6m, surface area, A = 100m2, Volume, V =60m

3. River sand media of

varying sizes ranging from 2-7mm was used as a substrate to fill up each cell. Media

porosity, n=0.44, HRT, t= 5 days.

Wastewater samples were analyzed according to Standard Methods for Analysis (APHA,

1989).

Model Development

STELLA® 6.0, software was used to simulate the processes that take place in the CW

during phosphorus removal. Firstly a conceptual model was developed on the major

mechanisms of phosphorus removal in the wetland and then followed by identifying the

major mathematical equations which govern the processes.


A mass balance through modeling for the major processes (transformation and removal)

taking place in the wetland was done so as to see the ones that have greater percentages in

phosphorus removal. Figure 1 below shows the mass balance of different processes that take

place in CW for the transformation and removal of phosphorus quantitatively.


347

Figure 1: Mass balance of phosphorus removal processes in a CW cell

The major removal of the phosphorus in the constructed wetlands was through sand

adsorption which accounted for 4.563 mg/l and plants uptake for 2.335 mg/l. This shows that

phosphorus removal is mainly through adsorption and followed by plants uptake, this is in

line with other reported studies elsewhere (Mann, 1996).

CONCLUSIONS

Based on the model results, it can be concluded that substratum adsorption of the wetland

plays a very important role in the removal of phosphorus in Constructed Wetlands.

ACKNOWLEDGEMENTS

The authors would like to thank WaterNet for funding this study through the Master

Programme in Integrated Water Resources Management at the University of Dar es Salaam.

REFERENCES APHA 1989 Standard methods for Examination of Water and Wastewater. American Public Health association,

American Water Works Association, Water Control Federation: Washington.

Mann, R.A., 1996, Phosphorus Removal by Constructed Wetlands: Substratum Adsorption. Ph D Thesis,

Faculty of Science and Technology, University of Western Sydney (Hawkesbury).


348

The multifunctional role of constructed urban wetlands in the

Nummela Community, Finland (PO.62)

Outi Salminen1, Pasi Valkama

2, Sami Haapanala

3, Hannele Ahponen

1, Kari

Rantakokko4, Teuvo Vessman

5, Anne Ojala

6, Leena Linden

7, Veli-Matti

Väänänen1, Kirsti Lahti

2, Harri Vasander

1, Timo Vesala

3 and Eero Nikinmaa

1

1University of Helsinki, Department of Forest Sciences ([email protected];

[email protected]; [email protected]; [email protected];

[email protected])

2Water Protection Association of the River Vantaa and Helsinki Region (VHVSY)

([email protected])

3University of Helsinki, Department of Physics; (Sami [email protected])

4Uusimaa Centre for Economic Development, Transport and the Environment (UUDELY)

([email protected])

5Municipality of Vihti ([email protected])

6University of Helsinki, Department of Environmental Sciences ([email protected])

7University of Helsinki, Department of Agricultural Sciences ([email protected])

INTRODUCTION

Urbanization and associated imperviousness changes water balance causing increased

flooding and draught. Runoff washes pollutants from urban surfaces degrading water quality

in receiving waters. Climate change is expected to increase rainfall intensities and duration,

as well as intensify heat and drought periods in Southern Finland. Habitats become degraded

and fragmented, and urban dwellers distanced from local nature.

Urban wetlands are constructed primarily as mitigation tools to reduce changes in water

balance and to improve water quality. The impact of wetlands on climate change is a balance

composed by carbon (C) bound to fast growing and slowly decomposing vegetation, and the

release of greenhouse gases (GHGs) from microbial decomposition. In our ongoing studies

we investigate the role of constructed urban wetlands and their design on water environment

mitigation, GHG balance, vegetation establishment, and habitats.

METHODS

Our two study wetlands are located within an urbanized 550 hectare watershed, in the

catchment of Lake Enäjärvi in the Nummela Community, Municipality of Vihti, Southern

Finland. The Nummela ”Gateway” and the Nummela ”Niittu” wetlands are constructed as

water environment mitigation landscapes and as urban parks. The two wetlands vary in

design and have been monitored since establishment in 2010 and 2013 respectively. Holistic

understanding of design and function relationships as well as public awareness rising are

sought.

To measure water environment mitigation services by the wetlands, water quality is

monitored both continuously and with grab sampling at the inflow and outflow of the

wetlands. To elucidate the wetland C dynamics, CO2 and CH4 exchanges are measured year

round with the micrometeorological eddy covariance (EC) technique, footprint area covering

the constructed wetland, and biomass bound C (above and below ground) determined. The

CO2 and CH4 gas concentrations are also monitored continuously in water at the inlet and

outlet of the constructed wetland. Vegetation establishment is monitored at 0,5 m2 plots.

Wildlife monitoring has included nesting avian pairs and amphibians.


349

RESULTS AND DICUSSION

Vegetation self-establishment and wildlife The wetlands were excavated on abandoned

crop fields. Vegetation was allowed to self-establish. Annual monitoring for species and

vegetation coverage in summers 2010, 2011 and 2012 at the Gateway wetland revealed that

vegetation self-establishment was rapid, rich in taxa, and dominated by native wetland

species. Only two alien plant species were identified: Elodea canadensis in deep water and

Epilobium adenocaulon in dryer meadow areas. Amphibians (frogs and newts) and nesting

water fowl, wading birds, and small gulls found the wetlands already the first spring

following winter time construction. The public found the constructed wetland parks very

appealing due to the diversity of plants and animals seen, and because these native landscapes

``changed every visit`` providing ``endless surprises`` and ´´pride´´ of own neighborhood.

Water quality Nummela Gateway Wetland reduces the entrance of pollutants such as

phosphorus rich clay particles into the Lake Enäjärvi. Observed pollutant reductions vary and

depend on season, inflow concentration, characteristics of the preceding hydrological events

(both recent and over the ongoing hydrological year) as well as design and maturity of the

constructed wetland. The Gateway wetland water surface composes only 0,1 % of its

watershed area. While event reductions have proven a strong positive impact on water

quality, monitored two month snowmelt period averages are modest. Long term monitoring is

underway to investigate how the densely vegetated yet modest in size wetland will perform in

a full hydrological year scale. Design of the ``Niittu`` wetland includes repeated wetland

sections intercepting flow, and a flood meadow area.

Greenhouse gases GHGs have been continuously monitored at the Gateway wetland by

EC from air (measures fluxes) and directly from water (measures concentrations).

Measurements of GHG concentration in water during winter, spring, and summer 2012-2013

indicate that the site has been a slight source of CO2 and CH4 into the atmosphere in winter.

The beginning of growth season caused a strong peak in CH4 emissions, yet the fluxes soon

leveled down close to the winter time levels. The GHG concentrations in the water have been

sensitive to changes in flow rates. A mid-winter snowmelt event caused strong CH4 peak.

Polluted spills within the urbanized areas have impacted water quality as well as GHG levels

in the water (Graph 1.).


350

Graph 1. Turbidity reduction is demonstrated at the wetland with associated impact on water oxygen

content. Right: The turbidity peak coinciding CH4 concentration peak on 13 March2013 in water is a

result of an urban spill of unknown contamination. The CH4 flux measurement at the frozen wetland

show a slight steady source. Snowmelt occurred later in April in 2013.

CONCLUSIONS

Monitoring of constructed wetlands for vegetation has shown rapid and rich self-

establishment with native species. Birds, frogs and newts rapidly found the new habitats. The

public recognized biodiversity as a source of local pride in the constructed wetland parks.

Water quality is improved by the Nummela Gateway wetland at the event scale yet long term

benefit estimation requires full hydrological year monitoring, which is underway. GHGs

presence in water is impacted by flows and urban spills. Seasons impact the observed fluxes.

The established parks are oases of biodiversity within their urbanized watershed.

ACKNOWLEDGEMENTS The project is kindly funded by the EC Life+11 ENV/FI/991 Urban Oases.

Continuous monitoring for water quality was conducted by the skilled staff of the Luode Consulting Oy.

REFERENCES Salminen, O., Ahponen, H., Valkama, P., Vessman, T., Rantakokko, K., Vaahtera, E., Taylor, A., Vasander, H.,

& Nikinmaa, E. (2012) TEEB Nordic case: Benefits of green infrastructure – socioeconomic importance of

constructed urban wetlands (Nummela, Finland). In Kettunen et al. Socio-economic importance of ecosystem

services in the Nordic Countries – Synthesis in the context of The Economics of Ecosystems and Biodiversity

(TEEB). Nordic Council of Ministers, Copenhagen, p. 247-254.


351

Land based sources pollution management in a sub-basin

catchment area of a freshwater lake (PO.65)

aKemal Gunes,

bFabio Masi,

aSelma Ayaz,

aHuseyin Tufekci

aTUBITAK Marmara Research Center, Environment Institute, Gebze, Kocaeli, 41470

Turkey ([email protected])

bIRIDRA, Via La Marmora 51, 50121 Florence, Italy

ABSTRACT

This study was performed in Hoyran sub-basin of Eğridir Lake which is the second largest

freshwater lake of Turkey. There are 8 settlement units, total pollution is nearly 35 000 in

Hoyran sub-basin and all domestic wastewaters are discharged to Eğirdir Lake. The lake is

used as potable water source and the wastewaters directly discharged to the lake by means of

a drainage channel without being subjected to any treatment. Additionally, an intense cherry

production is carried out in the sub-basin. The diffuse pollution which originates from

agricultural areas also reaches to the lake through the same drainage channel. Field and

laboratory studies were conducted within the scope of this study and constructed wetland or

riverine constructed wetland systems were designed for each settlement unit. With the

designed systems, it was aimed to treat both domestic wastewaters and agriculture diffuse

pollution sources through the riverine constructed wetland system. Thus, the most suitable

treatment systems would be designed for the municipalities with sufficient economical

opportunities and the treatment of the diffuse polluters which is one of the most important

polluting sources will have been provided by using the results. Additionally, maximum

disposal methods were assessed before the diffuse and point polluters reach to the lake by

sampling and analyzing wastewater from certain distances until the drainage channel reach to

the lake. . Constructed wetland and riverine constructed wetland designs were prepared

based on BOD5 removal, and the stipulated BOD5 removal target varied between 76-99,9%

according to the systems designed. One of the riverine wetlands designed has a length of

2500m which is considered as a large system as compared to similar implementations.

INTRODUCTION

Eğirdir Lake is the second largest freshwater lake of Turkey and the lake is utilized as

irrigation and potable water source. Intensive agriculture is carried out around the lake.

Various studies have been conducted since 1999 with regard to determining and preventing

the domestic, industrial and agriculture pollutants (Ugurlu et al., 1999; Gunes et al., 2001,

2004, 2006, 2007).

Constructed wetland systems are ecological treatment methods their success particularly in

the treatment of domestic wastewaters is proven. Riverine wetland systems are one of the

ecological treatment methods which are rather used in the diffuse pollution treatment.

However, riverine wetland systems were assessed both in domestic and diffuse pollution

treatment in this study and the treatment target will have reached the maximum level when

several stream bed plants are ued. Besides, the channel will provide further treatment of the

treated waters which are discharged from the riverine wetland systems.

The difference of this study from the previous ones is that it covers the studies where

different ecological treatment methods are assessed together and sustainable treatment

methods are planned which can be considered as model for the areas with similar properties

such as Eğridir Lake.


352

METHOD

Primarily, the domestic wastewater characteristic which originates from the settlement

units in Hoyran which is a sub-basin of Eğridir Lake was determined. Accordingly, the

average main daily flow was determined at the main sewage discharge points which are under

the responsibility of the municipality. Furthermore, sampling studies were done in the certain

distances of the drainage channel where lake domestic waters and agriculture run-off waters

are discharged. The most suitable treatment systems were designed by analyzing the

socioeconomic structure of the region. The per capite daily flow in the settlement units where

population is the most does not exceed 100 liters. BOD5 and COD average values which

were analyzed in 8 settlement units in the sub-basin were taken into consideration and these

values were selected as 250-500 mg/l for the design.

RESULT AND CONCLUSION

With this study, a current drainage channel was designed to convert the domestic waters

and agriculture run-off waters to be treated in Hoyran which is one of the most important 3

sub-basins of Eğridir Lake sub-basin. Thus, a low cost treatment system (riverine constructed

wetland) was turned into an applicable project. Additionally, constructed wetland systems

were designed to the 6 settlement units whose population is between 500 and 10500. It is a

remarkable issue that the imhoff tanks which are designed for constructed wetlands are in a

size to address a population of 10500.

As a result, the ecological treatment systems which are meticulously prepared and

managed in freshwater lake basins which are used as a potable water source where the

construction and operation of advanced treatment technologies is not economically possible

will be effective in the protection of the sensitive areas.

ACKNOWLEDGEMENT

The authors thank to the Governorship of Isparta for their support. The study was

conducted in TUBITAK MRC.

REFERENCES Ugurlu, A., Latifoglu, A., Akin, B., Onocak, T., 1999. Conservation of Lake Egirdir as a Potable Water

Source. Hacettepe University, Environment Applications and Research Center, Ankara.

Gunes, K., Tufekci, H., Karakas, D., Morkoc, E., Tufekci, V., Okay, O., Tolun, L., Karakoc, F.T., 2001.

Monitoring of Lake Egirdir Surface Waters Qualitiy. TUBITAK MRC. Energy Systems and

Environmental Research Institute, Gebze, Kocaeli.

Gunes, K., Ayaz, S., Akca, L., Tuncsiper, B. 2004. Natural treatment application technologies in Lake

Egirdir Basin (I. Stage). TUBITAK MRC, Energy Systems and Environment Institute, Gebze,

Kocaeli/Turkey.

Gunes, K., Ayaz, S., Tufekci, H. 2006. Lake Egirdir Hoyran Basin domestic wastewater treatment by

natural treatment systems. TUBITAK MRC, Chemistry and Environment Institute,

Gebze, Kocaeli/Turkey.

Gunes, K., Ayaz, S., Tufekci, H. 2007. Gelendost and Yaka settlements’ domestic wastewater

treatment by natural treatment technologies in Lake Egirdir Basin. TUBITAK MRC, Chemistry

and Environment Institute, Gebze, Kocaeli/Turkey.


353

Performance of Constructed Wetlands for CSO treatment: an

pilot scale study in Portugal (P.87)

Ana Galvãoa, Joana Pisoeiro

a, Filipa Ferreira

a, José Matos

a

aCEHIDRO, Instituto Superior Técnico, Technical University of Lisbon, Av. Rovisco Pais,

1049-001 Lisbon, Portugal ([email protected], [email protected],

[email protected], [email protected])

INTRODUCTION

The discharge of non-treated overflows during wet weather conditions is a problem being

faced by many countries of Europe, due to the pollution introduced into the receiving waters.

The control of this type of pollution is therefore essential to ensure the protection of aquatic

ecosystems. The use of constructed wetlands to reduce pollution from combined sewer

overflows (CSOs) has been applied with success (Uhl and Dittmer, 2005) and several studies

have demonstrated good performances (Van de Moortel et al., 2009; Fournel et al., 2012).

The intermittent nature of the operation conditions of these systems can lead to very long

inundation times and also to very long drought periods (Henrich et al, 2007). The influence of

these factors in the behaviour of CW for CSO treatment is still not fully understood and more

work is needed to evaluate the extent to which they influence performance.

In the present study a pilot scale experimental installation was set in a wastewater

treatment plant (WWTP) to simulate treatment of combined sewer overflows. Performance

was evaluated during the second year of operation in two different feeding regimes.

METHODS

The experimental setup was installed in Frielas WWTP, located in Lisbon, Portugal. Each

bed has a surface area of 0.2 m2 with 40 cm depth and a porosity of 30%. Beds were divided

into two groups, A (CW1 and CW2) and B (CW3 and CW4), to evaluate the effect of

different hydraulic loads. Each group had one of the beds planted with Phragmites australis

while the other was left without vegetation to act as control. The beds Group A received 10 l

each and feed flow was doubled for the beds of Group B. Each feeding was conducted as a

batch-feed, using the effluent from the screening chamber of the WWTP, in order to prevent

clogging. When there were no rain events prior to feeding, CSO was simulated by a dilution

with potable water (approximately 1/3 sewage and 2/3 water). The water used had previously

been stored in order to ensure the absence of free chlorine.

The study was conducted in two different phases: Phase I, from April to June 2012, where

beds were fed once per week; Phase II, from November 2012 to January 2013, where beds

were fed considering a random pattern, to simulate the stochastic nature of overflows that

usually occur in WWTP.

Samples were collected once to twice between feedings and analysed for Chemical

Oxygen Demand (COD), Total Suspended Solids (TSS) and Enterococcus. Experimental

conditions such as temperature, redox potential, pH and dissolved oxygen were also

measured in situ.


During Phase I removal efficiencies were of 74-90% for COD, 88-97% for TSS and 4.3-

4.8 log for enterococcus. A strong decay in COD and TSS concentrations was observed in the

first 24h, as can be observed in Fig.1 for COD concentrations. Enterococcus decrease showed

a more linear decrease over a 7 day period. No significant differences were found in the COD

removal efficiencies of beds in group A, while in Group B the planted bed had a lower


354

removal efficiency than the unplanted control. This behaviour could have been due to

clogging of the filter media, possibly due to a very dense root system.

Fig. 1. COD concentrations (CW1 to CW4 beds) (April 3 to June 8, 2012).

During Phase II only COD was measured with removal efficiencies in group A of 77% for

both beds, 69% for the unplanted control in group B and 59% for the planted bed. Phase II

had several consecutive days of feeding and a reduction in the removal efficiency of COD

was observed after more than 8 days of daily feeding.

CONCLUSIONS

The results obtained in this second year showed that the main reduction in COD and TSS

concentration occurred in the first 24h, suggesting that most CWs intended for CSO treatment

could be designed for 1 day retention time, thus allowing significant land reduction.

Results revealed that the planted bed with the highest hydraulic loading had poorer

performance, which could have been due to very dense root system that developed in the

second year of operation. Feeding in consecutive days is possible but more studies are needed

to determine a minimum resting time between loads.

ACKNOWLEDGEMENTS

This work was supported by project SIMAI – PTDC/AAC-AMB/102634/2008, funded by

FCT – Fundação para a Ciência e Tecnologia and by project TRUST (http://www.trust-i.net),

funded under the Seventh Framework Programme.

REFERENCES Fournel, J., Millot, Y, Grasmick, A. and Molle, P. (2012) Treatment performances of vertical flow constructed

wetland treating urban runoff: design comparison. 13th International Conference on Wetland Systems for Water

Pollution Control, November 25–29, Perth, Australia.

Henrichs, M., Langergraber, G. and Uhl, M. (2007) Modelling of organic matter degradation in constructed

wetlands for treatment of combined sewer overflow. Science of the Total Environ., 380: 196-209.

Uhl, M. and Dittmer, U. (2005) Constructed wetlands for CSO treatment: an overview of practice and research

in Germany. Water Science and Techology, 51 (9): 23–30.

Van de Moortel, A., Rousseau, D., Tack, F. and Pauw, N. (2009) A comparative study of surface and subsurface

flow constructed wetlands for treatment of combined sewer overflows: A greenhouse experiment. Ecological

Engineering, 35: 175-183.

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CW4

Feeding


355

The effect of reclamation on water environment of coastal

wetlands (P.101)

Yu Zhanga, Baoshan Cui

a

aSchool of Environment, Beijing Normal University, State Key Joint Laboratory of

Environmental Simulation and Pollution Control, Beijing 100875, China

([email protected])

INTRODUCTION

Reclamation is one of the important and effective ways to ease the contradiction between

supply and demand of land and expand the social development. Science the foundation of

New China, the area of reclamation has reached 12000 km2 [2]. With the development of

social economy and population growth, land demand has increased rapidly, and the

reclamation activities are increasingly frequent. Though reclamation brings the great social

and economic benefits, it has irreversible effects on water environment of coastal wetlands,

such as salinity, temperature and chemical oxygen demand, polycyclic aromatic hydrocarbon.

METHODS

Data acquisition of the study is based on the method of literature research and sampling

data.

Literature research data obtained by the Elsevier website, including the Yellow River

Delta, the Liaohe River Delta, the Pear River Delta, the Yangtze River Delta. Sampling data

was collected in the water of Yellow River Delta in 2013.


The effect of reclamation on the salinity

The regional areas that salinity was lower than of 27 were respectively 1680, 2240, 8250

and 8370 square kilometers. Compared with the previous year, low salt area expanded, and

low salt area of the Yangtze River Delta decreased.

Fig.1. The area where salinity is lower than 27

The effect of reclamation on the chemical oxygen demand

The chemical oxygen demand test, which is widely used as an indicator to identify the

characteristics of water, could be disturbed by artificial disturbance such as reclamation.

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Yangtze River

Pear River

Area 1680 2240 8250 8370

Are

a (K

m2)


356

Chemical oxygen demand was the lowest in the yellow, and that of Pear River Delta was the

highest.

The effect of reclamation on polycyclic aromatic hydrocarbon

The concentration of polycyclic aromatic hydrocarbon (PAHs) was the lowest in the

Yellow River Delta, and concentration of PAHs was from 65 ng L-1

to 345 ng L-1

with a mean

value of 205 ng L-1

. PAHs concentrations of the Yangtze River Delta and Pearl River Delta

were respectively 944 ng L-1

-6655 ng L-1

with a mean value is 3800 ng L-1

, 242 ng L-1-6235 ng

L-1

with a mean value of 3239 ng L-1.

Table 1 PAHs concentration in water of delta

Location ∑PAHs (ng L-1

) References

The Pear River Delta 944-6655 Luo et al., 2004

The Yangtze River Delta 242-6235 Feng et al., 2007

The Yellow River Delta 65-345 Wang et al., 2009

The Liaohe Delta 430-660 Han et al., 2009

CONCLUSIONS

According to the above analysis, we could reach the following conclusions. The

investigation data showed that the effects of the reclamation of coastal wetland on salinity,

COD and polycyclic aromatic hydrocarbons. The biggest influence was the Pearl River Delta

with the rapidly economic development. This change is related to different uses of the

reclamation.

ACKNOWLEDGEMENTS

This research was funded by China National Funds for Distinguished Young Scientists

(51125035) and National Natural Science Foundation of China (41071330).

REFERENCES Luo, X.J., Mai, B.X., Yang, Q.S., Fu, J.M. Sheng, G.Y., Wang, Z.S. (2004) Polycyclic aromatic hydrocarbons

(PAHs) and organochlorine pesticides in water columns from the Pearl River and the Macao harbor in the Pearl

River Delta in South China. Mar Pollut Bull. 48:1102-1115

Feng, C.L., Xia, X.H., Shen, Z.Y., Zhou, Z. (2007) Distribution and sources of polycyclic aromatic

hydrocarbons in Wuhan section of the Yangtze River, China. Environ Monit Assess.133:447-458.

Wang, L.L., Yang, Z.F., Niu, J.F., Wang, J.Y. (2009)Characterization, ecological risk assessment and source

diagnostics of polycyclic aromatic hydrocarbons in water column of the Yellow River Delta, one of the most

plenty biodiversity zones in the world. J Hazard Mater.169:460-5.


357

Calibrating a simulation tool for constructed wetlands for

combined sewer overflow treatment with field data (PO.155)

Katharina Tonderaa, Daniel Meyer

b, Johannes Pinnekamp

a

aInstitute of Environmental Engineering of RWTH Aachen, 52056 Aachen, Germany

([email protected])

bIRSTEA Lyon (formerly Cemagref), 5 rue de la Doua - CS70077, 69626 Villeurbanne,

France ([email protected])

INTRODUCTION

Combined sewer overflows (CSOs) can release enormous loads of critical substances into

surface waters. Numerous pollutants can be retained or even eliminated with retention soil

filters (RSFs) in order to reduce negative impacts on surface water bodies (Dittmer &

Schmitt, 2011; Tondera et al., 2013a,b). In German combined sewer systems, RSFs are

located in series with stormwater tanks to their overflows. In the Federal State of North

Rhine-Westphalia, about 1,870 stormwater tanks for CSO are operated - 120 of them are

combined with RSFs. Currently several research projects in European countries deal with

specific national adaptations of RSFs for CSO treatment (Meyer et al., 2013a).

Dynamic simulations of the sewer systems are strictly required to design fitting RSF sizes

under highly varying operational conditions due to the stochastic nature of rain events. The

simplified modelling tool called RSF_Sim was developed to prevision load limits in terms of

hydraulics and pollutants (Meyer et al., 2013b). To validate the given model data from full-

scale plants are necessary, especially from events under critical operational conditions. This

article shows results of a simulation study focussed on NH4-N in comparison to other filters.

METHODS

In the recent research project “Optimisation of retention soil filters in combined sewer

systems”, a RSF with a surface area of 2,210 m2 and a retention volume of approximately

4,200 m3 in North Rhine-Westphalia was monitored. Beside flow measurements, one focus

was set on NH4-N-retention. Inflow and outflow concentrations were continuously recorded

(interval 5 min, details in Tondera et al., 2013b). Out of 11 events observed between October

2011 and July 2012, a selection of usable ones had to be made: During 5 events with

complete data sets breakthroughs could be detected under ponding conditions. This means

that the outflow concentration passed a low level before a strong increase due to adsorption

limits. Simulation methods of the model RSF_Sim are given in Meyer et al. (2013) – as a key

function NH4-N adsorption is calculated by a two-stage linear isotherm with a critical

retention load correlated to the beginning of breakthrough.


The variation of hydraulic loads (tab.1) shows comparatively low values for events with

NH4-N-breakthroughs. This can be explained due to the relatively high inflow concentrations.

Calibration values for the slope of first linear isotherm stage (A1) are relatively high,

resulting in high retention values and indicating high treatment performances. The slope A2

(describing retention after the beginning of breakthrough) varies within a narrow range.

The example of an outflow concentration curve calibration (fig.1) shows a good match of

simulated and measured values after about 6 h. Before, only the measurements signalize a

peak. This can be explained on one hand by the permanently dipped online probes. On the

other hand, this phenomenon was observed on other filters (with lower intensities). Dittmer &

Schmitt (2011) suggested that it might be a result of wash-outs from mineralised sediment.


358

Tab. 1. Feeding event characteristics and simulation results.

event 10/12/2011 12/16/2011 12/20/2011 12/30/2011 01/02/2012 RSF EH*

Hyd. load [m3/m

2] 1.40 1.52 0.93 0.53 0.56 1.97 – 15.8

Inflow conc. [g/m3] 9.3 8.7 11.2 10.1 21.5 1.45 – 5.93

Slope A1 [-] 95 75 95 50 110 35 - 60

Conc. C1 [g/m3] 0.1 0.1 0.1 0.1 0.1 0.1

Slope A2 [-] 0.6 0.7 0.3 0.9 1.0 0.5 - 2

Retention** [g/m2] 5.7 4.5 5.7 3.0 6.6 3.1 – 5.3

* data RSF Saarbrücken-Ensheim (Dittmer & Schmitt, 2011), simulation results from Meyer et al., 2013

** Simulated mass per filter surface when effluent concentration equal to C1 (before breakthrough)

Fig. 1. Measured / simulated inflow and outflow NH4-N concentrations over time (10/12/2011)

CONCLUSIONS

The simulation study gives plausible results for all selected feeding events. Compared to

the dataset from the RSF Ensheim, the investigated filter shows higher NH4-N retentions due

to higher inflow concentrations and removal performance. By increasing the simulation

database, the potential prediction of treatment performances by RSF_Sim was improved.

Nevertheless, the number of simulated RSF is still too small to give guarantees.

ACKNOWLEDGEMENTS

The RSF investigation project was funded by the Ministry for Climate Protection,

Environment, Agriculture, Nature Conservation and Consumer Protection of the German

Federal State of North Rhine-Westphalia.

REFERENCES Dittmer U., Schmitt T.G. (2011). Purification Processes in Biofilter Systems for CSO Treatment. Proceedings

12th Int. Conf. on Urban Drainage, Porto Alegre, Brazil

Meyer, D., Molle, P., Esser, D., Troesch, S., Masi, F., Dittmer, U. (2013a). Constructed Wetlands for Combined

Sewer Overflow Treatment – Comparison of German, French and Italian Approaches. Water, 5, 1-12, ISSN

2073-4441

Meyer, D., Dittmer, U., Forquet, N., Molle, P. (2013b). Simplified modelling of constructed wetlands for

combined sewer overflow treatment - results from German systems and discussion of adaptation in France. this

issue

Tondera K., Koenen S., Pinnekamp J. (2013a). Survey monitoring results on the reduction of micropollutants,

bacteria, bacteriophages and TSS in retention soil filters. WST, in press.

Tondera K., Koenen S., Pinnekamp J. (2013b). Combined Sewer Overflow Treatment: Removal of oxygen-

depleting parameters through Retention Soil Filters. Proceeding of the 8th

International Conference

NOVATECH, Lyon, France.

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impact of global climate change on wetland systems · 2013. 10. 11. · poster abstract . abstracts...

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