advanced systems for the enhancement of the environmental
TRANSCRIPT
Advanced systems for the enhancement of the
environmental performance of WINEries in
Cyprus (WINEC)
Deliverable 20
Evaluation of the long term performance of the WWWT system:
robustness of the overall system, photocatalyst activity with
extended use, performance, effluent quality
First Edition Nicosia, September 2012
2
Table of Contents
1. Summary ................................................................................................................................................. 5
2. Winery wastewater treatment plant (WWWTP) ..................................................................................... 6
2.1 Membrane Bioreactor (MBR) - operation ......................................................................................... 6
3. Characterization of influent and effluent of WWWTP ........................................................................... 9
3.1 Sampling............................................................................................................................................ 9
3.2 Methods of characterization .............................................................................................................. 9
3.2.1 Chemical oxygen demand (COD) .............................................................................................. 9
3.2.2 Biological oxygen demand (BOD5) ......................................................................................... 10
3.2.3 pH ............................................................................................................................................. 10
3.2.4 Total nitrogen ........................................................................................................................... 10
3.2.5 Total phosphorus ...................................................................................................................... 11
3.2.6 Total solids (TS) ....................................................................................................................... 11
3.2.7 Total suspended solids (TSS) ................................................................................................... 11
3.2.8 Total volatile solids (TVS) and Volatile suspended solids (VSS) ............................................ 12
3.2.9 Oil and grease ........................................................................................................................... 12
3.3 Characterization of Tsiakkas winery wastewater (assessment of the influent and effluent of the
WWWTP).............................................................................................................................................. 12
3.4 PLC/Scada System - Modifications for further optimization of the process .................................. 18
4. Solar Fenton operation in industrial scale ............................................................................................. 20
4.1Experimental set up in industrial scale ............................................................................................. 20
4.2 Winery effluents - Characterization of winery wastewater ............................................................. 22
4.3 Analytical equipment and methods for solar Fenton experiments .................................................. 22
A) Daphtoxkit FTM magna toxicity test ........................................................................................... 23
B) Phytotestkit microbiotest toxicity test ........................................................................................ 24
4.4 Industrial scale solar Fenton treatment using effluents treated by MBR ........................................ 24
4.4.1 Solar Fenton treatment .............................................................................................................. 24
4.4.2 Evaluation of the toxicity ......................................................................................................... 26
3
(A) D. magna species .................................................................................................................... 26
(B) Phytotoxicity ........................................................................................................................... 27
5. Conclusions ........................................................................................................................................... 31
6. References ............................................................................................................................................. 32
4
Abbreviations
AOPs Advanced Oxidation Processes
APHA American Public Health Association
BOD5 Biochemical Oxygen Demand
COD Chemical Oxygen Demand
DO Dissolved Oxygen
HF Hollow Fibre
FS Flat Sheet
KHP potassium hydrogen phthalate
MBR Membrane Bioreactor
MLSS Mixed Liqueur Suspended Solids
MF Microfiltration
MT Multi-Tubular
NF Nanofiltration
TN Total Nitrogen
TP Total Phosphorus
TS Total Solids
TSS Total Suspended Solids
TVS Total Volatile Solids
VSS Volatile Suspended Solis
PMB phosphomolybdenum blue
UF UltraFiltration
WWWTP Winery WasteWater Treatment Plant
5
1. Summary
In this deliverable the technical characteristics of the membrane bioreactor (MBR) and the solar
photocatalytic plant, operating Tsiakkas winery are presented. In addition, the basic parameters of the
characterization of Tsiakkas winery wastewater i) influent and ii) effluent of winery wastewater
treatment plant (WWWTP), from September 2011 to September 2012, are listed. Online measurements
were electronically retrieved from a PLC/Scada system in the WWWTP of Tsiakkas; and the unit
modifications that were undertaken by the manufacturing company, S.K. Euromarket Ltd, in order to
optimize further the process are also described. The final aim of this report is also to investigate the
efficiency of the solar-Fenton for the removal of the organic content of pretreated effluent by MBR at
the industrial scale. The work focused on the COD - DOC removal and the evaluation of the toxicity
(Daphnia magna, Sinapis alba, Lepidium sativum, Sorghumm saccharatum).
6
2. Winery wastewater treatment plant (WWWTP)
The technology used in the present study was a Membrane Bioreactor (MBR) followed by Advanced
Solar Oxidation (SOLAR). In Schematic 1, the WWWTP that was installed at Tsiakkas winery, in
Pelendri, Limassol, Cyprus, is shown.
Schematic 1: Winery WasteWater Treatment Plant (WWWTP) in Tsiakkas winery
The WWWTP consists of the following 3 parts:
Preliminary treatment (screening, equalization / balancing tank, pH adjustment)
Biological Treatment (pre-aeration /nitrification, membrane reactor, storage / irrigation tank)
Advanced Oxidation Process - Solar Fenton (compound parabolic collectors)
2.1 Membrane Bioreactor (MBR) - operation
Membrane Bioreactor is an acknowledged key treatment process for wastewater reclamation and water
recycling, as it offers the advantages of biomass separation and concentration (Hai et al. 2011). The
membrane bioreactor is an absolute barrier to solids and microorganisms thus providing a removal
system of a high Mixed Liqueur Suspended Solids (MLSS) concentration, which can reach 30 g L-1 in
industrial applications.
The MBR process is a suspended growth activated sludge system that utilises microporous membranes
for solid/liquid separation in lieu of secondary clarifiers. The typical arrangement shown in Schematic 2,
MBR
Solar photocatalytic
plant
7
includes submerged membranes in the aerated portion of the bioreactor, an anoxic zone and internal
mixed liquor recycle.
Schematic 2: Schematic description of the Membrane Bioreactor system
The performance of the MBR process is determined by the configuration of the membranes, which is
determined by the geometry (planar or cylindrical), mounting and orientation in relation to the flow of
water. Membranes can be immersed into the biological tank of the wastewater treatment plant (WWTP)
or can be located in a different container directly linked to the tank. The feed to the aeration tank is
pressurized and circulated through the tank module with the use of a pump. A valve assists in the
accumulation of the wastewater constituents on the membranes. Floc forming and dispersed
microorganisms are kept in the MBR system which biodegrade and transform pollutants.
Membrane processes include microfiltration (MF) (0.1-10 μm), ultrafiltration (UF) (0.005-0.1 μm),
nanofiltration (NF) (0.001-0.1 μm), reverse osmosis (0.001-0.0001 μm), dialysis and electrodialysis.
(Metcalf and Eddy, 2003). The range of actual wastewater filtration size lies in the range of 0.0001 to
1μm, in order to include dissolved wastewater constituents.
The commercial configuration of MBR membranes has three principal set-ups, the flat sheet (FS), the
hollow fibre (HF) and the multi-tubular (MT). The choice of membrane and system configuration is
optimised when the factors of minimizing clogging and deterioration are considered.
The constituent material of MBR is ceramic or polymeric, and organic. The main materials of
membranes include polypropylene, cellulose acetate, aromatic polyamides and thin-film composite.
Composite membranes have thin cellulose acetate bonding, polyamide or another active layer (mainly
0.15-0.25 μm) and a thicker porous substrate which provides stability.
8
The highest efficiency has been noted in MBR with HF configuration operating in the UF range, with an
efficiency of >90%, as they are most efficient in comparison to NF and MF in the removal of
biodegradable organics, hardness, heavy metals, nitrates, synthetic organic compounds and viruses.
More attention is given to the HF membranes, and FS MBRs are not so common in the market, both in
the UF and MF range (Metcalf and Eddy, 2003).
The initial concentration and removal efficiency of pollutants are not directly associated, but chemical
and physical properties of pollutants have been linked to their removal efficiency (Metcalf and Eddy,
2003).
The primary removal of particles from wastewater in MBR is achieved by sieving with the application
of hydraulic force on the wastewater through the membrane. All large molecules are gathered by the
membrane as they cannot pass through, and can be collected. In this way the separation of suspended
solids is not restricted only to the sludge settling characteristics but to filtration characteristics of the
membrane bioreactor, which will define the separation efficiency. The membrane has to be strong to
hold the hydraulic pressure exerted by the wastewater shear force and the pore size and membrane
material will determine filtration efficiency. Generally, the pore size used is under 0.1 μm, so that the
MBR produces a clarified and disinfected effluent. It also concentrates the biomass, which results in a
reduced necessary tank size and increase in the efficiency of the bio-treatment process. This moreover,
removes the need for sedimentation removal of solids. The treated water is of high purity in respect to
dissolved constituents such as organic matter and ammonia, which are significantly removed (Metcalf
and Eddy, 2003). To assess the effectiveness of MBR removal, the effluent can be analysed with regard
to its physical parameter qualities. As a result, due to the lack of biomass washout from the reactor the
effluent is of high quality regarding its DOC, BOD, COD, NH4, TOC and TSS measurements
(Radjenovic et al. 2007).
9
3. Characterization of influent and effluent of WWWTP
Sample testing was frequently conducted for the control of the operating conditions of the WWWT
plant. Since the fabrication of the plant (September 2011) quality analyses were periodically conducted
from the inlet and outlet of the membrane bioreactor, in order to ensure the proper operation of the plant.
3.1 Sampling
Influent and effluent samples were collected from Tsiakkas WWWTP, every month since the installation
and operation of the unit. The physicochemical characteristics of wastewater produced from the wine
production were identified, as well as the same characteristics of the winery wastewater after MBR
treatment. Specifically, the following parameters have been determined: pH, Total Solids (TS), Total
Volatile Solids (TVS), Total Suspended Solids (TSS), Suspended Volatile Solids (SVS), Biochemical
Oxygen Demand (BOD5), Chemical Oxygen Demand (COD), Total Nitrogen (TN), Total Phosphorus
(TP) and oils and grease. All samples were analyzed (characterized) according to standard methods that
are given below (APHA, 1998).
3.2 Methods of characterization
3.2.1 Chemical oxygen demand (COD)
Chemical oxygen demand (COD) is defined as the quantity of oxygen which is required to oxidize the
organic matter present in a sample under controlled conditions (temperature, time, oxidizing agent).
Merck®Spectroquant kits were used for the COD determination. The measurement range for the samples
analysed was between 25 and 10000 mg O2 L-1. An appropriate volume of sample, which was filtered
with 0.22 μm filters (Millipore), was mixed with the reaction solution in the test tube and heated for two
hours at 148 oC in a thermo block. After cooling down to room temperature the test tube was introduced
into the photometer (Photolab S6) and measured at 445 nm. The calibration was made from a standard
aqueous solution of potassium hydrogen phthalate (KHP) over the range 25-10000 mg L-1. The method
is analogous to EPA 410.4, US Standard Method 5220D and ISO 15705.
10
3.2.2 Biological oxygen demand (BOD5)
The BOD test measures the molecular oxygen utilized during a specified incubation period for the
biochemical degradation (in presence of microorganisms) of organic material (carbonaceous demand)
and the oxygen used to oxidize inorganic material such as sulfides and ferrous iron.
The method consists of filling with sample, to overflowing, an airtight bottle of the specified size and
incubating it at the specified temperature (20 oC) for 5 days. Dissolved oxygen (DO) is measured
initially and after incubation, and the BOD is computed from the difference between initial and final
DO. Because the initial DO is determined shortly after the dilution is made, all oxygen uptake occurring
after this measurement is included in the BOD measurement. BOD measurements in a 5-day test period
are known as BOD5. BOD was determined using the 444406 OxiDirect meter. The aforementioned
analytical determination (expect 5210B) was conducted according to APHA (American Public Health
Association), Standard Methods.
3.2.3 pH
Laboratory pH measurements were carried out using a PL-600 lab pH meter (EZDO pH/mV/Temp
meter) equipped with a standard glass electrode. A calibration of the pH-meter was performed using two
standard buffer solutions at pH 4.00 and pH 7.00 (obtained from Panreac).
3.2.4 Total nitrogen
Total nitrogen (TN) can be determined through oxidative digestion of all nitrogenous compounds to
nitrate according to the persulfate method. Alkaline oxidation at 100 oC to 110 oC converts organic and
inorganic nitrogen to nitrate. Total nitrogen is determined by analyzing the nitrate in the digestate. A
standard curve is prepared by plotting the absorbance of the standard nitrate solutions carried through
the digestion procedure against their concentrations. The TN of the sample is computed by the standard
curve. For this method, Merck®Spectroquant kits were used. The method used is the Standard Method
4500N C Persulfate method.
11
3.2.5 Total phosphorus
Total phosphorus (TP) is measured by the persulfate digestion procedure. The sample is digested with a
sulfuric acid solution containing ammonium persulfate. Ammonium molybdate and potassium
antimonyl tartrate react in acidic medium with orthophosphate ions to form a phosphomolybdic acid.
Ascorbic acid reduces this acid to phosphomolybdenum blue (PMB) that is determined photometrically.
A standard curve is prepared by plotting the absorbance of the standard P solutions carried through the
digestion procedure against their concentrations. The TP of the sample is computed by the standard
curve. For this method, Merck®Spectroquant kits were also used. The method used is the EPA method
365.3.
3.2.6 Total solids (TS)
To determine the total solids (TS), a well-mixed sample is evaporated in a weighed dish and dried to
constant weight in an oven at 103-105oC. The increase in weight over that of the empty dish represents
the total solids. The aforementioned analytical determination (expect 2540B) was conducted according
to APHA, Standard Methods.
𝑚𝑔𝑇𝑆/𝐿 = (𝐴−𝐵)×100𝑠𝑎𝑚𝑝𝑙𝑒 𝑣𝑜𝑙𝑢𝑚𝑒,𝑚𝐿
(1)
A is the weight of dried residue + dish, (mg) and B is the weight of dish, (mg).
3.2.7 Total suspended solids (TSS)
Total suspended solids (TSS) refer to matter suspended in water or wastewater. A well-mixed sample is
filtered through a weighed standard glass-fiber filter (Sartorius Stedim Biotech) and the residue retained
on the filter is dried to a constant weight at 103 oC to 105 oC. The increase in weight of the filter
represents the TSS.
𝑚𝑔𝑇𝑆𝑆/𝐿 = (𝐴−𝐵)×100𝑠𝑎𝑚𝑝𝑙𝑒 𝑣𝑜𝑙𝑢𝑚𝑒,𝑚𝐿
(2)
where A is the weight of filter with the dried residue (mg) and B is the weight of filter (mg). The
aforementioned analytical determinations (except 2540D) were conducted according to APHA.
12
3.2.8 Total volatile solids (TVS) and Volatile suspended solids (VSS)
To determine the Total Volatile Solids (TVS) and Volatile Suspended Solids (VSS), the residue after
drying at 103-105 oC taken from the implementation of the method for Total Solids and Total Suspended
Solids is ignited to constant weight at 550 oC. The remaining solids represent the fixed total or
suspended solids, while the weight lost on ignition is the volatile solids, as shown in Eq (3). The
aforementioned analytical determination (expect 2540E) was conducted according to APHA, Standard
Methods.
𝑚𝑔𝑉𝑇𝑆&𝑉𝑆𝑆/𝐿 = (𝐴−𝐵)×100𝑠𝑎𝑚𝑝𝑙𝑒 𝑣𝑜𝑙𝑢𝑚𝑒,𝑚𝐿
(3)
where A is the weight of residue + dish or filter before ignition, (mg) and the B is the weight of residue
+ dish or filter after ignition, (mg).
3.2.9 Oil and grease
“Oil and grease” is defined as any material recovered as a substance soluble in the solvent. It includes
other material extracted by the solvent from an acidified sample (such as sulfur compounds, certain
organic dyes, and chlorophyll) and not volatilized during the test. The aforementioned analytical
determination (expect 5520B Participation-Gravimetric method) was conducted according to APHA,
Standard Methods.
Dissolved or emulsified oil and grease is extracted from water by intimate contact with an extracting
solvent (e.g. n-hexane). Some extractable, especially unsaturated fats and fatty acids, oxidize readily;
hence, special precautions regarding temperature and solvent vapor displacement are included to
minimize this effect. Organic solvents shaken with some samples may form an emulsion that is very
difficult to break, but this method includes a means for handling such emulsions.
3.3 Characterization of Tsiakkas winery wastewater (assessment of the influent and effluent of the
WWWTP)
Table 1 shows the basic parameters of the characterization of Tsiakkas winery wastewater i) influent and
ii) effluent of WWWTP, from September 2011 to September 2012. These values were obtained from
multiple sample analyses (3 different samples at the same period) and are the average values of the
13
parameters measured. Sampling of the influent and the effluent of the MBR, took place every month,
since September 2011.
As it can be observed, the first samples taken in September 2011 were only from the influent due to the
fact that the MBR had just started working and the commissioning of the WWWTP was on going. Since
the beginning of October 2011 both influent and effluent samples were taken for characterization. Extra
samples (October 2011, November 2011, and February 2012) of the effluent were taken when required
or deemed necessary from the scientific team of UCY and the manufacturing company S.K. Euromarket.
The green columns of the Table 1 contain the characteristics of the influent and the blue columns of the
characteristics of the effluent of WWWTP.
14
Table 1: Characteristic parameters of Tsiakkas winery wastewater (influent and effluent) of MBR
Parameters MBR
influent
(2/9/11)
MBR
influent
(5/9/11)
MBR
influent
(20/9/11)
MBR
influent
(5/10/11)
MBR
effluent
(5/10/11)
MBR
effluent
(19/10/11)
MBR
influent
(7/11/11)
MBR
effluent
(7/11/11)
pH 6.1 6.53 6.21 5.8 7.34 7.2 5.15 8.6
COD (mg L-1) 11670 12200 7620 9835 200 31 5640 53
BOD5 (mg L-1) 8106 7230 2691 1910 <5 <5 240 <5
TS (mg L-1) 7752 7375 7362 5807 2830 50 3900 35
TVS (mg L-1) 5250 5002 5100 2543 585 27 2721 17
TSS (mg L-1) 1197 1680 1810 1485 73 <7 700 11
VSS (mg L-1) 972 1022 1120 1078 36.5 - 570 -
TN (mg L-1) 10.8 15.5 9 11.3 1.7 <2 (1.28) 18 5.7
TP (mg L-1) 13.2 14 10.2 3.3 0.4 0.88 3.3 0.5
Oil and grease
(mg L-1)
4 5.2 10.2 2.4 <0.5 0.2 2 ~ 0
15
Parameters MBR
effluent
(14/11/11)
MBR
influent
(15/12/11)
MBR
effluent
(15/12/11)
MBR
effluent
(19/12/11)
MBR
influent
(20/1/12)
MBR
effluent
(20/1/12)
MBR
influent
(2/2/12)
MBR
effluent
(2/2/12)
MBR
influent
(12/3/12)
MBR
effluent
(12/3/12)
pH 8.31 5.5 8.6 8.3 5.7 7.5 5 6.5 6 7.5
COD (mg L-1) 35 4950 36 53 5650 158 6910 185 4200 245
BOD5 (mg L-1) <5 210 - <5 250 <5 290 <5 152 22
TS (mg L-1) 70 3100 270 310 4570 785 5900 897 2150 725
TVS (mg L-1) 51 2070 138 212 3189 518 4120 672 1852 516
TSS (mg L-1) 8 500 3 5 920 8 1288 6.2 145 10
VSS (mg L-1) - 279 - - 724 - 985 - 101 -
TN (mg L-1) 1.5 12 5 4 12.9 0.9 4.2 0.5 1.9 0.2
TP (mg L-1) 0.17 4 0.5 0.4 5.2 0.4 4.4 0.4 9.8 0.4
Oil and grease
(mg L-1)
0.2 2.1 0.2 0.1 2.4 0.2 3 0.1 4 ~0
16
Parameters MBR
influent
(5/4/12)
MBR
effluent
(5/4/12)
MBR
influent
(8/5/12)
MBR
effluent
(8/5/12)
MBR
influent
(27/6/12)
MBR
effluent
(27/6/12)
MBR
influent
(3/7/12)
MBR
effluent
(3/7/12)
pH 5.5 8.2 5.7 8.5 6.2 8.3 6 8.2
COD (mg L-1) 1250 81 3810 185 1085 87 2750 114
BOD5 (mg L-1) 107 <5 372 25 75 10 150 7
TS (mg L-1) 1756 270 4378 2789 1555 1410 1785 1250
TVS (mg L-1) 1025 138 3210 1980 975 758 1125 985
TSS (mg L-1) 426 7 1200 - 980 17 1200 15
VSS (mg L-1) 217 - 724 - 498 - 850 -
TN (mg L-1) 0.7 0.4 2.1 1.4 2.4 0.5 45 19
TP (mg L-1) 2.1 0.2 0.4 0.1 0.7 0.1 5.2 0.3
Oil and grease
(mg L-1)
10.9 ~0 12.4 0.4 17 ~0 30.4 ~0
17
Parameters MBR
influent
(9/8/12)
MBR
effluent
(9/8/12)
MBR
influent
(3/9/12)
MBR
effluent
(3/9/12)
MBR
influent
(15/9/2012)
MBR
effluent
(15/9/2012)
pH 5.6 8.1 5.7 7.8 4.8 8.0
COD (mg L-1) 5020 120 4830 108 4150 150
BOD5 (mg L-1) 725 <5 954 15 500 <5
TS (mg L-1) 3472 230 3270 - 2750 200
TVS (mg L-1) 2810 150 2420 - 2014 -
TSS (mg L-1) 2075 8 1507 11 1352 10
VSS (mg L-1) - - - - - -
TN (mg L-1) 3.7 0.9 5.7 2.6 5.2 3.6
TP (mg L-1) 2.0 0.5 2.3 0.7 0.9 0.3
Oil and grease
(mg L-1)
12.7 0.2 11.7 0.3 11.2 ~0
18
The above mentioned results, from the characterization of winery wastewater before and after biological
treatment (MBR) show the strength of the biological treatment and the difficulty in reducing the organic
load of winery wastewater by a biological process.
3.4 PLC/Scada System - Modifications for further optimization of the process
PLC/Scada system allows sophisticated system control of operation according to the process control
philosophy and also allows the collection of data in relation to the equipment and measurements from
the instrumentation. These data can be used for assessment of operation and modification of the
operation parameters for optimization.
1. PH measurement system
pH values were recorded by the PLC/Scada System, and system performance was evaluated. The system
response was not as expected and following an investigation the installation of pH sensor on to a factory
made holder was found regularly blocked. It was then decided to install a sensor on the main feed pipe
for direct pH measurement and correction. Following an additional data analysis, it was confirmed that
the response of the pH correction system was satisfactory.
2. Permeate flow adjustment
The system design with reference to the membrane surface area was based on an estimation of the
maximum daily flow. The flow to the WWWT (winery wastewater treatment) plant was measured and
recorded via the PLC/Scada system. In addition, throughout regular on-site visits and measurement of
DO level into MBR reactor, it was found that DO level in period of low flows was <1.0 mg L-1. This
value in comparison to the design DO level (2 mg L-1) was below the expected value, in contradiction to
the fact that lower flows reveal lower organic loadings and therefore lower oxygen demand.
After investigation and review of the control philosophy it was found that during low flow periods, the
permeate pump was required to work at short intervals on the basis of initial set flow rate 240 L hr-1.
During no permeate flow, the operation of the submerged membrane unit’s (SMU) air scouring blower
was set through frequency inverter to work at lower speed. This affected the overall oxygen transfer rate
since the air supplies to membrane scouring was also taken into account to contribute in oxygen transfer
19
during the design stage. After the modification of the rotation speed of air scouring blower to higher
level during no permeate flow period, the DO level raised to the expected optimal level.
3. Adjustment for seasonality
Further to the above findings and modifications and after observations by the end user concerning high
power consumption during periods of no flow or minimum activity in the wastewater production, the
operation of the system was gradually adjusted to reduce overall power consumption by reducing
operation hours of the aeration blower. After monitoring the system performance and recording
operating parameters and optimum operational strategy mode was establish whereby main air blower
was set into ON/OFF operation at regular intervals. This data was given to the end user to enable future
adjustment of operation during no or low flow conditions.
The fluctuations in the hydraulic and organic loading of WWWT plan (see Table 1) require adjustment
and optimization of the operation. The adjustments were necessary to insure that final effluent quality is
maintained within the set limits and at the same time achieve minimum possible running cost that is
primarily related to the operation of the air blowers.
Having the submerged membrane unit (SMU) as the main solid separation process after the aerobic
biological stage, gave the system another advantage. This is the fact that minimal particulate residual
organic load was measured during the periods where high COD values were measured from the samples
received.
All samples with higher COD concentration were directly related to the low availability of dissolved
oxygen in the process reactor. After adjustment of the operation of both air blowers (oxidation and air
scouring of SMU) the system performance in terms of organic pollutants reduction was reinstalled.
No other mistaken were observed and after the aforementioned technical alternations and adjustments
the system operated smoothly.
20
4. Solar Fenton operation in industrial scale
4.1Experimental set up in industrial scale
The solar Fenton treatment were carried out in a compound parabolic collector (solar photocatalytic
plant) installed at the premises of Tsiakkas winery in Limassol (Pelendri), (Schematic 3).
Schematic 3: Solar photocatalytic plant
The solar photocatalytic plant comprised glass tubes mounted on a fixed platform tilted at the local
latitude (35o) and through a meander flow, was operated in batch mode. The reflecting surface is
constructed of resistant and highly reflecting polished aluminium. The contaminated water flows
directly from one tube to the other and finally to a reservoir tank. A centrifugal pump returns the water
to the collectors in a closed circuit. The overall capacity of the reactor VT consists of the total irradiated
volume Vi (tubes volume) and the dead reactor volume (tank, piping and valves). Storage tank, air
blower, control panel, pipes, and fittings complete the installations, shown in Table 2.
21
The UV solar radiation was continuously recorded, with a UV radiometer. During the loading of the
reactor with the chemicals, the collectors were covered with a thick plastic sheet to avoid any
photoreaction during preparation. At the beginning the reactor was filled with the biologically treated
winery wastewater (MBR). Then a sample was taken representing the initial concentration of the
effluent. The pH was then adjusted with dilute H2SO4 2M and the appropriate volume of ferrous iron
solution was added. Mixing was following for 15 min. Then the hydrogen peroxide was added, a sample
was taken after 15 min of dark Fenton process (zero-illumination time) and the collectors were
uncovered. That time is consider time-zero for the photo-Fenton process. Samples were withdrawn
during the process, at periodic intervals and were further analyzed.
Table 2: Main characteristics of the solar photocatalytic plant
Characteristics Solar photocatalytic plant
Platform latitude (o) 35
Coordinates Latitude: 35° N
Longitude: 33.25 E
Modules 2
Total volume VT (L) 250
Irradiated volume Vi (L) 85.4
Number of tubes 24
Tube material Borosilicate
Tube length (mm) 1500
Diameter (mm) 50
Storage tank material Stainless Steel
Cover material Thick grey plastic sheet
22
4.2 Winery effluents - Characterization of winery wastewater
The biologically treated winery samples used for the experiments were collected after the MBR stage of
the winery wastewater treatment plant of Tsiakkas winery in Limassol, Cyprus. Samples after MBR
treatment were collected between September - October 2012. The samples were analyzed before use for
a number of quality characteristics, which are summarised in Table 3. These values were obtained from
multiple sample analyses (at least triplicate for each sample) and are the average values of the
parameters measured. All parameters were measured according to standard methods (APHA, 1998).
Table 3: Quality characteristics of winery wastewater effluent after biological treatment used in
industrial scale experiments
Parameter After biological treatment
pH (20 oC) 7.8 - 8.1
Total Solids (mg L-1) 200 - 230
Suspended Solids (mg L-1) 8 - 10
Total Nitrogen (mg L-1) 0.9 - 3.6
COD (mg L-1) 120 -150
Soluble BOD5 (mg L-1) <5
Total Phosphorous (mg L-1) 0.36 - 0.5
Fats and oils (mg L-1) 0 - 0.2
4.3 Analytical equipment and methods for solar Fenton experiments
For the solar-Fenton experiments, mineralization was monitored by measuring the chemical oxygen
demand (COD) with Merck®Spectroquant kits and dissolved organic carbon (DOC) by direct injection
of filtered samples into a Shimadzu TOC-VCPH/CPN, TOC analyser calibrated with standard solutions
of potassium hydrogen phthalate. The pH was measured using a multi-parameter measurement probe
23
(WTW InoLap Multilevel 3). Quantofix Peroxide-Test sticks (0-100 mg L-1 H2O2) were used to monitor
the elimination of unreacted hydrogen peroxide. These analytical test strips are used for the detection
and semiquantitative determination of residual concentrations of hydrogen peroxide (colorimetric
method).
Toxicity measurements were carried out in samples withdrawn at various times of the photocatalytic
treatment using: (a) the Daphtoxkit FTM magna toxicity test and (b) the Phytotestkit microbiotest toxicity
test. The toxicity tests were conducted according to the standard testing protocols for Daphnia magna
and the phytotoxicity with 3 species of plant seeds: (i) the monocotyl Sorgho (Sorghum saccharatum)
(ii) the dicotyls garden cress (Lepidium sativum) and (iii) the mustard (Sinapis alba).
It is important to mention that H2O2 present in solar Fenton treated samples can affect toxicity
measurements and therefore had to be eliminated. The residual H2O2 was removed from the treated
samples with catalase solution ((17000 U mL-1), Micrococcus lysodeikticus, Fluka). Catalase is an
enzyme which catalyzes the decomposition of H2O2 to water and molecular oxygen.
A) Daphtoxkit FTM magna toxicity test
This test, which is currently used in many laboratories worldwide for toxicity monitoring purposes, is
based on the observation of the freshwater species Daphnia magna immobilization after 24 and 48 hours
of exposure in the samples.
The experimental procedure for conducting this assay was based on the ISO 6341 standard protocol. The
water used to activate and hatch the organisms (72-90 h) was synthetic freshwater containing NaHCO3,
CaCl2, MgSO4 and KCl (dilution solution). Sufficient amount of dissolved oxygen (~5 mg L-1) was
achieved by aeration. The dilution water was prepared a day prior to its use, in order to provide oxygen
saturation and ensure complete salts dissolution and homogenization. Cultures were grown under
continuous illumination of 6000 lux at a constant temperature of 20-22 ºC. Appropriate adjustment of
the pH value of the samples in the range of 7±0.5 was carried out with 1M solution of NaOH or HCl.
Two hours before testing, the neonates were fed using a dilution of Spirulina microalgae in order to
preclude mortality by starvation, thus avoiding biased test results. Analysis was carried out on specific
test plates which were filled with the examined samples. For statistically acceptable evaluation of the
effects, each test sample as well as the control, was tested in quadruplicate. After the transfer of five
Daphnia neonates into the cells, the test plates were covered and incubated at 20 ºC in the dark.
24
Observations of test populations were made at 24 and 48 hours of exposure and any dead or
immobilized neonates were recorded. The neonates were considered immobile, if after 24 or 48 h of
incubation with the toxicant they remained settled at the bottom or did not resume swimming within the
observation period. It should be noted that tests in which the control survival was less than 90% were
invalid and were repeated.
B) Phytotestkit microbiotest toxicity test
The Phytotestkit microbiotest is measuring the decrease (or the absence) of germination and early
growth of plants which are exposed directly to the samples spiked onto a thick filter paper. A control test
was performed using tap water. The plants used for the Phytotestkit microbiotest were: the monocotyl
Sorgho (Sorghum saccharatum), the dicotyl garden cress (Lepidium sativum) and the dicotyl mustard
(Sinapis alba). These species are frequently used in phytotoxicity analyses due to their rapid
germination and growth of roots and shoots and their sensitivity to low concentrations of phytotoxic
substances.
Seeds of the selected test plant(s) are positioned at equal distance near the middle ridge of the test plate,
on a black filter paper placed on top of the spiked filter paper (20 mL sample). After closing the test
plates with their transparent cover, the test plates are placed vertically in a holder and incubated at 25 oC
and for 3 days. At the end of the incubation period a digital picture was taken of the test plates which the
germinated plants can clearly be seen underneath the transparent cover. The pictures were stored in a
computer file and the length measurements of the roots and the shoots were performed using the Image
Tool 3.0 for Windows. Measurements of roots and shoots length were also performed manually using a
ruler. The bioassays were carried out in three replicates for each sample and for each type of plant.
4.4 Industrial scale solar Fenton treatment using effluents treated by MBR
4.4.1 Solar Fenton treatment
Solar Fenton operation was carried out using 3 mg L-1 of Fe2+ and 500 mg L-1 H2O2 for MBR effluent,
which were the optimum concentrations found in pilot scale experiments.
Figure 1 shows the COD removal for the pretreated by MBR effluent vs. the normalized time, t30W,n
(optimum conditions: [Fe2+]=3 mg L-1, [H2O2]=500 mg L-1). After 180 min of treatment (t30W 65 min)
25
the COD removal of the pretreated by MBR effluent was 84%; this was in agreement with the maximum
degradation observed in the pilot scale experiment (85%) (Deliverable 37). It must be noted that the
degradation of the organic compounds in the effluent at the industrial scale plant, started 15 min before
uncovering the reactor (texp=-15 min, dark Fenton reaction) thus reducing the initial COD value by
40%. In the case of industrial scale plant, the time before uncovering the reactor was higher than in the
pilot scale, due to the fact that the tube volume was bigger, and was needed more time for recirculation
of the effluent.
Figure 1: COD removal of MBR effluent during solar Fenton oxidation in the solar photocatalytic plant;
[Fe2+]0=3 mg L-1 and [H2O2]0=500 mg L-1, pH=2.8-3.0.
DOC determination showed that moderate mineralization of the organics occurs during the solar Fenton
process. The DOC was reduced to 58% after illumination for 180 min (t30W 65 min) as shown in Figure
2. A slight reduction of the DOC (10%) was observed 15 min before uncovering the reactor (texp=-15
min, dark Fenton reaction). The COD removal (84%) was found to be higher than the DOC removal
(58%), which suggests that the remaining organics, after the end of the solar Fenton treatment, have the
carbon at higher oxidation state. The corresponding DOC removal of MBR effluent, in the case of pilot
experiment (Deliverable 37), was slightly higher (68%) than in the industrial scale experiment, probably
due to the different composition of the initial effluent.
26
Figure 2: DOC removal of MBR effluent during solar Fenton oxidation in the solar photocatalytic plant;
[Fe2+]0=3 mg L-1 and [H2O2]0= 500 mg L-1, pH=2.8-3.0.
4.4.2 Evaluation of the toxicity
From the above findings it is obvious that complete mineralization was not achieved. Hence, it was
imperative to investigate the possible toxicity of the oxidation products formed during the photo Fenton
process. This would enable a more complete evaluation of the efficiency and environmental safety of the
applied technology. Ecotoxicological evaluations include the fate of the toxicant in the aquatic and
terrestrial environment, since winery wastewater will be used mostly for irrigation of vineyards and/or
will be disposed of into surface water.
(A) D. magna species
The toxicity tests were performed using D. magna species. Young daphnies, aged less than 24 hours at
the start of the test, were exposed to the test substance at a range of concentrations for a period of 24 and
48 hours. Immobilization was recorded at 24 and 48 hours and compared with control values. A set of
control toxicity tests were performed by exposing D. magna to the wastewater samples.
The toxicity test was further conducted on samples taken from the solar Fenton process (for both
biologically pretreated winery effluents) at various times of treatment (0-240 min). It should be noted
that the results are presented as a function of the actual experimental time (texp) instead of the
27
normalised illumination time (t30WT,n) for practical and comparison purposes, in order to be the same
experimental time for all toxicity experiments.
As shown in Figure 3, the raw pretreated by MBR effluent was found to be relatively non toxic to D.
magna (13% and 20% immobilization after 24 and 48 h of exposure). The toxicity to D. magna do not
decreased, possibly due to the formation of toxic by-products immobilization after the first 30 min of 48
h of exposure. After 60 and 90 min of solar treatment the toxicity decreased to 7 and 0% after 48 h of
exposure. It is important though to highlight that after 180 min the toxicity decreased to zero after 24 h
and 48 h of exposure.
Figure 3: Evolution of toxicity to D. magna during the photocatalytic degradation in solar
photocatalytic plant, of the pretreated by MBR effluent; [Fe2+]0=3 mg L-1 and [H2O2]0=500 mg L-1.
(B) Phytotoxicity
Phytotoxicity testing was conducted according to the standard testing protocols using 3 type of plant
seeds: (i) the monocotyl Sorgho (Sorghum saccharatum) (ii) the dicotyls garden cress (Lepidium
sativum) and (iii) the mustard (Sinapis alba). The test results were evaluated comparing the mean
number of germinated seeds and the mean root and shoot length for the three replicates in the control
and in each of the examined sample. The percentage effect of the chemical compounds on seed
germination inhibition (GI), root growth inhibition (RI) and shoot growth inhibition (SI) was calculated
applying the formula showing by Eq. (5).
28
100% ×−
=A
BAeffect (5)
The phytotoxicity test was further conducted on samples taken from the solar Fenton process (for both
biologically pretreated winery effluents) at various times of treatment (0-180 min). It should be noted
that the results are presented as a function of the actual experimental time (texp) instead of the
normalised illumination time (t30WT,n) for practical and comparison purposes, in order to have the same
experimental time for all toxicity experiments.
A. Germination Inhibition
As shown in Figure 4, the raw pretreated by MBR effluent caused inhibition of the order of 0 to 10% on
the germination for the three plants, Lepidium sativum (0%), Sinapis alba (10%) and Sorghum
saccharatum (5%). The solar Fenton process did not exert any significant influence on seed germination
and the inhibition level was altered from 0 to 15%, for the pretreated by MBR effluent. As shown in
Figure 7, after 90 and 120 min of solar Fenton treatment, the GI to Sinapis alba was the highest (15%),
due to the subsequent formation of by-products which were toxic to these seeds. After 180 min of
treatment, the GI decreased to zero for all three plants.
Figure 4: % effect of the pretreated by MBR effluent during solar Fenton process in the solar
photocatalytic plant, on seed germination; [Fe2+]0=3 mg L-1 and [H2O2]0=500 mg L-1.
29
B. Shoot Inhibition
The shoot growth inhibition profile vs. the photocatalytic time is shown in Figure 5 for the pretreated by
MBR effluent. As shown in Figure 8, the highest SI was 10% for Sinapis alba while the lowest SI was
3.9% for Lepidium sativum at the raw pretreated by SBR effluent. The shoot inhibition for all three plant
species increased the first 30 and 60 min, due to the subsequent formation of by-products which were
toxic, and the highest values were for Sinapis alba (30%), Lepidium sativum (17.4%) and Sorghum
saccharatum (50.1%). After 90 min the SI decreased and finally after the end of the treatment (180 min)
was almost eliminated at the end of the treatment, Sinapis alba (1.1%), Lepidium sativum (2.3%) and
Sorghum saccharatum (7.6%).
Figure 5: % effect of the pretreated by MBR effluent during the solar Fenton process in the
photocatalytic plant, on shoot inhibition; [Fe2+]0=3 mg L-1 and [H2O2]0=500 mg L-1.
C. Root Inhibition
As shown in Figure 6 the raw pretreated by MBR effluent, caused inhibition of the order of 5.9 to 18.7%
on root growth for the three plants. After 30 min the RI of the two plants increased rapidly from 8.9 to
42.3% for Sinapis alba and from 5.9 to 39% for Lepidium sativum, due to the subsequence formation of
toxic by-products, while the RI for Sorghum saccharatum was the same as the raw wastewater. After 60
min of treatment the RI of the three plants decreased and at the end of the treatment decreased to 29.2%
for Sinapis alba, to 20.2% for Lepidium sativum and to 22.4% for Sorghum saccharatum. At the end of
30
the treatment (240 min), the RI was almost eliminated for Sinapis alba (6.7%), for Lepidium sativum
(3.8%) and Sorghum saccharatum (1.6%).
Figure 6: % effect of the pretreated by MBR effluent during the solar Fenton process in the solar
photocatalytic plant, on root inhibition; [Fe2+]0=3 mg L-1 and [H2O2]0=500 mg L-1.
31
5. Conclusions
This study aims at the evaluation of the WWWTP performance, containing quantified information on
the photocatalyst activity and the overall system robustness and performance. The physicochemical
characteristics of wastewater produced from the wine production process were identified, as well as the
same characteristics of the winery wastewater after MBR treatment.
The organic content removal of winery wastewater effluent, after biological treatment (MBR), was
studied by means of industrial scale solar Fenton oxidation process. The industrial scale solar operation
was carried out at the optimum experimental conditions found in the pilot scale experiments (prototype
photocatalytic reactor) (Deliverable 37), in order to ensure the efficiency of solar Fenton at a bigger
scale too. The study included the determination of the mineralization of the effluent organic load (COD
and DOC), and the evaluation of the toxicity (Daphnia magna, Sinapis alba, Lepidium sativum,
Sorghumm saccharatum). The conclusion drawn from the present study can be summarized as follows:
Biological treatment (MBR) proved to be a good solution for organic load removal of winery
wastewater.
Chemical oxidation (solar Fenton) can be used for complete mineralization
Solar Fenton oxidation at industrial scale, proved to be efficient in organic content removal of
MBR effluent. Organic matter degradation increases with increasing treatment time and can
reach COD removal value as high as 84%, after 180 min of solar Fenton treatment.
Solar Fenton oxidation is able to reduce the toxicity of pretreated by MBR effluent, to the
microorganism D. magna and phytotoxicity.
Combined biological treatment and AOPs (solar Fenton oxidation), proved to be promising
alternative for the removal of organic load of winery wastewater.
32
6. References
Anastasiou, N., Monou, M., Mantzavinos, D., Kassinos, D., 2009. Monitoring of the quality of winery
influents/effluents and polishing of partially treated winery flows by homogeneous Fe(II) photo-
oxidation, Desalination 248, 836-842.
Arienzo, M., Christen, E.W., Quayle, W.C., 2009. Phytotoxicity testing of winery wastewater for
constructed wetland treatment. Journal of Hazardous Materials 169, 94-99.
Evgenidou, E., Konstantinou, I., Fytianos, K., Poulios, I., 2007. Oxidation of two organophosphorous
insecticides by the photo-assisted Fenton reaction. Water Research 41, 2015-2027.
Garcia-Montano, J., Torrades, F., García-Hortal, J.A., Domènech, X., Peral, J., 2006. Degradation of
Procion Red H-E7B reactive dye by coupling a photo-Fenton system with a sequencing batch reactor.
Journal of Hazardous Material 134, 220-229.
Gernjak, W., Fuerhacker, M., Fernandez-Ibanez, P., Blanco, J., Malato, S., 2006. Solar photo-Fenton
treatment-Process parameters and process control. Applied Catalysis B: Environmental 64, 121-130.
Hai, F.I., Yamamoto, K., Nakajima, F., Fukushi, K., 2011. Bioaugmented membrane bioreactor (MBR)
with a GAC-packed zone for high rate textile wastewater treatment. Water Research 45, 2199-2206.
Lucas, M.S., Mosteo, R., Maldonado, M.I., Malato, S., Peres, J.A., 2009. Solar photochemical treatment
of winery wastewater in a CPC reactor. Journal of Agriculture and Food Chemistry 57, 11242-11248.
Lucas, M.S., Peres, J.A., 2006. Decolorization of the azo dye reactive black 5 by Fenton and photo-
Fenton oxidation. Dyes Pigments 71, 236-244.
Lucas, M.S., Peres, J.A., Li Puma, G., 2010. Treatment of winery wastewater by ozone-based advanced
oxidation procesess (O3, O3/UV and O3/UV/H2O2) in a pilot-scale bubble column reactor and process
economics. Separation and Purification Technology 72, 235-241.
Malato, S., and Caceres, J., 2001. Degradation of Imidacloprid in Water by Photo-Fenton and TiO2
Photocatalysis at a Solar Pilot Plant: A Comparative Study. Environmental Science Technology 35,
4359-4366.
33
Malato, S., Fernandez-Ibanez, P., Maldonado, M.I., Blanco, J., Gernjak, W., 2009. Decontamination
and disinfection of water by solar photocatalysis: Recent overview and trends. Catalysis Today 147, 1-
59.
Maldonado, M.I., Passarinho, P.C., Oller, I., Gernjak, W., Fernández P., Blanco, J., Malato, S, 2007.
Photocatalytic degradation of EU priority substances: A comparison between TiO2 and Fenton plus
photo-Fenton in a solar pilot plant. Journal of Photochemistry and Photobiology A: Chemistry 185, 354-
363.
Metcalf, Eddy, 2003. Wastewater Engineering: Treatment and Reuse, fourth Edition. McGraw-Hill, Inc.,
New York.
Mosteo, R., Sarasa, J., Ormad, M.P., Ovelleiro, J.L., 2008. Sequential Solar Photo-Fenton-Biological
System for the Treatment of Winery Wastewaters. Journal of Agricultural and Food Chemistry 58,
7333-7338.
Navarro, P., Sarasa, J., Sierra, D., Esteban, S., Ovelleiro, J.L., 2005. Degradation of wine industry
wastewaters by photocatalytic advanced oxidation. Water Science and Technology 51 (1), 113-120.
Nunez, L., Garcıa-Hortal, J.A., Torrades, F., 2007. Study of kinetic parameters related to the
decolourization and mineralization of reactive dyes from textile dyeing using Fenton and photo-Fenton
processes. Dyes and Pigments 75, 647-652.
Pariente, M.I., Martınez, F., Melero, J.A., Botas, J.A., Velegraki, T., Xekoukoulotakis, N.P.,
Mantzavinos, D., 2008. Heterogeneous photo-Fenton oxidation of benzoic acid in water: Effect of
operating conditions, reaction by-products and coupling with biological treatment. Applied Catalysis B:
Environmental 85, 24-32.
Perez, M., Torrades, F., Garcıa-Hortal, J.A., Domènech, X., Peral, J., 2002. Removal of organic
contaminants in paper pulp treatment effluents under Fenton and photo-Fenton conditions. Applied
Catalysis B-Environmental 36, 63-74.
Radjenovic, J., Petrovic, M., Barceló, D., 2007. Analysis of pharmaceuticals in wastewater and removal
using a membrane bioreactor. Analytical and Bioanalytical Chemistry 387, 1365-1377.