5.copy of ecosan-grey water

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S u s t a i n a b l e

S a n i t a t i o n

P r a c t i


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Sustainable Sanitation Practice 2 issue 1 /2009

Combined greywatereuse and rainwatharvesting in an

Greywater use inperi-urban

Greywater treatmein apartment

Combined greywate

treatment using a

Household greywatreatment

Issue 1


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Greywat

ertreatment andreuse


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Impressum

published by/ Medieninhaber, Herausgeber und Verleger

EcoSan ClubSchopenhauerstr. 15/8A-1180Vienna

Austriawww.ecosan.at

Editors/ RedaktionElke Mllegger, Gnter Langergraber, Markus Lechner EcoSan Club

Journal Manager/ Journal ManagementIsabelle Pavese

Contact/ [email protected]

Disclaimer/ Haftungsausschluss

The content of the articles does not necessarily reflect the views of EcoSan Club or theeditors and should not be acted upon without independent consideration andprofessional advice. EcoSan Club and the editors will not accept responsibility forany loss or damage suffered by any person acting or refraining from acting upon anymaterial contained in this publication.Die in den Artikeln vertretenen Standpunkte entsprechen nicht notwendigerweise der Haltung undAnsichten des EcoSan Clubs oder des Redaktionsteams. Der praktischen Anwendung dargestellter Inhaltemuss eine unabhngige Begutachtung und professionelle Beratung vorausgehen. EcoSan Club und dasRedaktionsteam haften in keiner Weise fr Schden (Sachschaden oder Personenschaden), die durch dieAnwendung, oder Nichtanwendung der in dieser Publikation vermittelten Inhalte, entstehen.

Reproduction/ ReproduktionPermission is granted for reproduction of this material, in whole or part, for education,scientific or development related purposes except those involving commercial sale,provided that full citation of the source is given. Cover photo excluded.Die Reproduktion, bernahme und Nutzung der Inhalte von SSP, vollstndig oder teilweise, frBildungszwecke, fr die Wissenschaft und im Zusammenhang mit Entwicklung ist unter Voraussetzung dervollstndigen Quellenangabe gestattet und erwnscht. Titelbild ausgenommen.

aim and scope/ Offenlegung der Blattlinie gem 25, Abs. 4 MediengesetzSustainable Sanitation Practice (SSP) aims to make available high quality informationon practical experiences with sustainable sanitation systems. For SSP a sanitationsystem is sustainable when it is not only economically viable, socially acceptable andtechnically and institutionally appropriate, but it should also protect the environmentand the natural resources. SSP is therefore fully in line with SuSanA, the SustainableSanitation Alliance (www.susana.org). SSP targets people that are interested insustainable sanitation systems and the practical approach to it. Articles are publishedafter blind review only. Sustainable Sanitation Practice is published quarterly. It isavailable for free on www.ecosan.at/ssp.Sustainable Sanitation Practice (SSP) hat zum Ziel praxisrelevante Information in hoher Qualitt im Zusammenhang mit sustainable sanitation bereit zu stellen. sustainable also nachhaltig ist einSanitrsystem fr SSP wenn es wirtschaftlich machbar, soziokulturell akzeptiert, technisch als auchinstitutionell angemessen ist und die Umwelt und deren Ressourcen schtzt. Diese Ansicht harmoniert mitSuSanA, the Sustainable Sanitation Alliance (www.susana.org). SSP richtet sich an Personen, die sich frdie praktische Umsetzung von sustainable sanitation interessieren. Artikel werden nur nach einerBegutachtung verffentlicht. Sustainable Sanitation Practice erschient vierteljhrlich, kostenlos unter:www.ecosan.at/ssp.

Information on the publisher / Offenlegung gem 25 Mediengesetzpublisher: EcoSan Club, Schopenhauerstr. 15/8, A-1180 Vienna, Austria chairperson: Gnter Langergraber website: http://www.ecosan.at/ scope: EcoSanClub was funded as a non profit association in 2002 by a group of people active inresearch and development as well as planning and consultancy in the field of sanitation.The underlying aim is the realisation of ecological concepts to close material cycles insettlements.Medieninhaber: EcoSan Club, Schopenhauerstr. 15/8, A-1180 Vienna, Austria Obmann: Gnter Langergraber Gegenstand des Vereins: Der EcoSan Club wurde 2002 als gemeinntziger Verein von einerGruppe von Personen gegrndet, die in Forschung, Entwicklung, Planung und Beratung in der

Siedlungshygiene - Sammlung, Behandlung oder Beseitigung flssiger und fester Abflle aus Siedlungen -ttig waren und sind. Das Ziel des EcoSan Clubs ist die Umsetzung kreislauforientierterSiedlungshygienekonzepte (EcoSan Konzepte) zu frdern, um einen Beitrag zum Schutz der Umwelt zu leisten.
http://www.ecosan.at/mailto:[email protected]://www.susana.org/http://www.ecosan.at/ssp.http://www.susana.org/http://www.ecosan.at/ssp.http://www.ecosan.at/mailto:[email protected]://www.susana.org/http://www.ecosan.at/ssp.http://www.susana.org/http://www.ecosan.at/ssp.http://www.ecosan.at/http://www.ecosan.at/


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fotolia. http://de.fotolia.com
http://de.fotolia.com/http://de.fotolia.com/


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E tor

With Sustainable Sanitation Practice (SSP) we try to make available high qualityinformation on practical experiences with available sustainable sanitation systems. SSP

should fill a gap that we have identified in the last few years in which sustainablesanitation has become an important issue that is discussed among many disciplines. ForSSP a sanitation system is sustainable when it is not only economically viable,socially acceptable and technically and institutionally appropriate, but it should alsoprotect the environment and the natural resources. SSP is therefore fully in line withSuSanA, the Sustainable Sanitation Alliance (www.susana.org).SSP is planned to be published quarterly, it will be available online from the journalhomepage at the EcoSan Club website (www.ecosan.at/ssp/) for free. Thematic issuesshall tackle selected fields of sustainable sanitation systems.Issue 1 is dedicated to "Greywater". Five contributions showing results from projects, inwhich members of the EcoSan Club Austria have been involved. The papers highlightexperiences from East Africa, the Middle East and Europe. Each manuscript has beenreviewed by two reviewers. By following this procedure we think that we could meet ourexpected quality standards.Greywater is wastewater generated from domestic processes such as dish washing,laundry and bathing, i.e. the part of the wastewater that was not in contact with humanexcreta. The general quality of greywater can be characterised by low contents ofnutrients (nitrogen and phosphorus) and low microbiological contamination (indicatororganisms and pathogens). Greywater can be treated effectively and is a good qualitysource to be reused for various purposes. However, if greywater is not treated anddischarged in the environment it can cause serious problems. Greywater issues aretherefore an important part within sustainable sanitation systems.The second issue is currently under preparation. The topic of Issue 2 will be "Successfulmodels for operation and maintenance of sanitation systems" and will be published inJanuary 2010. For this issue also experiences from outside EcoSan Club Austria will be

presented.person for the SSP editorial office, Ms. Isabelle Pavese (Email: [email protected]). We think

With best regards,Mllegger EcoSa n Club Austria(www.ecosan.at/ssp)

on e

- Combined greywater reuse and rainwater harvesting in anoffice building in Austria: analyses of practical operation

- Household greywater treatment for peri-urban areas ofNakuru Municipality, Kenya

....................................................................................................................................10

- Greywater use in peri-urban households in Kitgum, Uganda

16
http://www.susana.org/http://www.ecosan.at/ssp/)mailto:[email protected]).mailto:[email protected]).http://www.ecosan.at/ssp)http://www.susana.org/http://www.ecosan.at/ssp/)mailto:[email protected]).http://www.ecosan.at/ssp)


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overall project:

NASPA

Combined greywater reuse andrainwater

arvest n n an o ce u nn ustr a:

stractcombined system of greywater treatment and reuse in a multi storey office buildingbeen investigated over one year of operation. The system consists of an indoor

structed wetland, rainwater harvesting and water saving measures. The analysesered quantitative and qualitative aspects like the water saving potential andsico-chemical and microbiological parameters. The existing system has beenpared to three other water use scenarios by the calculation of capital costestments, re-investments) and operating costs (materials, labour and energy). Thelts showed that the system was capable to fulfil the physicochemical requirements

gest by different guidelines but could not ensure the hygienic quality for all

rating conditions. In comparison to a conventional system the combined system wasable to reduce the fresh water demand by more than 60%. The economic comparisonaled that the installed system is more expensive than rainwater harvesting only but

aper than greywater treatment only. The difference to the conventional system wasnly due to the additional labour costs for maintenance and operation. Non-monetary

IntroductionModern water use concepts forbuildings aim on saving naturalresources ensuring minimumemissions like carbon dioxideandwastewater.Beside theecologicalbenefits, economic but also additionalbenefits arise: using the internal watercycle as a visible design element andimproving the climate withinthe

building at the same time. In contrastto easily accountable benefitslikereduced freshwater consumption theformer are more difficult to account for.Nevertheless, they have to beconsidered

to allow a broaderapplication of so called green

technologies. Abroad application of such technologieswould bean important contribution tofreshwater conservation. Before lookingfor alternative water sources, the first

thing to consider is water savingmeasures. Nowadays, a variety ofsanitary equipment to reduce the dailywater consumption is available. Low flushtoilettes and dry urinals have becomecommon in many public and commercialbuildings. Alternatives for fresh watersources are rainwater harvesting andreuse of separated andtreated wastewater streamslike re water

Figure 1: Rainwater storagecanal (left) and indoor

households. The use of treated greywaterfor applications with lower water qualityrequirements like irrigation and toiletteflushing is not new. Water reuse viagreywater has been integrated ascomponent of innovative buildingconcepts since decades (Nolde, 1999).Although, the composition of greywater isdifferent to domestic wastewater in termsof organics, nutrients and microbiologicalcontamination, the treatment concepts

applied mainly originate fromwastewater treatment (Eriksson et al.,2009; Li et al., 2009). The applied systemsvary from extensive biological treatmentsuch as constructed wetlands (CWs) tomore sophisticated methods (Knerr et


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Gre water reuse in office buildin -

can be applied as single solutions or incombination. The users expect safe andclean water use at the sames ta nd ard a s wi th conventionalsystems. The question is how theapplied alternative concepts reach

these requirements (Reinoso et al.,2008). This paper attempts to describethe results of the analyses of one yearoperation of a combined system of watersaving, rainwater harvesting andgreywater reuse in a multi storeyoffice building in Austria. According tothe requirements for treated

- Suspended matter: Totalsuspended solids. - On-siteparameters: Dissolved oxygen (DO),

Electrical conductivity, Redox

Materials and methodsThe investigated building is a three storyoffice building with a total floor space of

2090 m2 and roof area of 460 m2. Thebuilding is workplace for nine fulltimeand five half-time employees. Water isalso used for the affiliated car wash andgarage. Beside the normal operation,the building serves also as venue forconferences and meetings. The buildinghas been constructed under the Austrianstandards for green housing withen er gy consumption below 10 kWh persquare meter and year. Construction wasfinished in 2003. It is connected to thepublic water supply and sewer system.

The lab analyses were carried out duringthree different sampling periods withmonthly grab sampling (during oneyear), daily grab sampling (for oneweek) and 2h mixed samples (for twodays). The applied indoor- greywatertreatment is a vertical flow sub surfaceCW with a surface area of 3 m2. Theconfiguration of the CW was 10 cm toplayer of coarse gravel, 60 cm main layer(1 -4 mm) and 20 cm drainage layer. The inflow was intermitted at a flow

rate of 15 L/min for one minute every

- Water saving measures: Low flushtoilets and dry urinals

- Rainwater harvesting: Roofcollection and outdoor storage inan open canal (Figure 1, left)

- Greywater treatment: In-door CWtreatment (Figure 1, right)

Quantitative and qualitativemeasurements Treated greywater and rainwater is

mixed in the water storage tank for non-potable use (16 m3) and partly circulatedover the indoor-CW to avoid odour. Alsothe rainwater stored out-door wascirculated via a separate line. Thescheme of the combined treatmentsystem is shown in Figure 2. Water flowwas measured continuously at thesampling points Q1-07 over a period of oneear. Additionall the followin

Figure 2: Scheme of the combinedgreywater and rainwater system.

Quantitative measurements havebeen carried out at points Q1 toQ7, qualitative sampling at points

- Organics: BOD5, COD, TOC.- Nutrients: Total Nitrogen, Ammonium,

Nitrite, Nitrate, Total phosphorus.- Microbiological parameters: Total

coliforms E coli Enterococci

Economic analysesThe economic analyses are based on adynamic cost calculation using anoverall interest rate of three percent fora life span of the system of 25 years and12 years for mechanical and electricalequipment, respectively (LAWA,

2005). The analyses comprisedinvestment costs, reinvestment costsand operation and maintenance costs.


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with the responsible operator. Tocompare the existing system with otherpossible options, the estimated costs ofthe system components reported atthe planning stage have been used. The fo llowing p lanning scenarios

Table 1: Average load conditions andremoval rates of organics and nutrients

- Conventional system- Greywater treatment andreuse only - Rainwaterharvesting only

Parameter Daily Reduction

Organic 22 g/d 7,3 g/(m2.d) 60 % 4,4 g/(m

Nitrogen load 12 g/d 4,0 g/(m2.d) 0 % 0 g/(m

Phosphorous 34 g/d 11,3 g/2

0 % 0 g/(m

Hydraulic load 3 m3/d 1 m3/(m2.d) -

n.a....not available; n.d...not

It is important to mention that the watersaving measures have been consideredas option for every planningscenario since the waterconsumption patterns directly influencethe economics of the different variants.

The economic benefit of water saving wascalculates based on the local tariffs forpublic drinking water supply andwastewater disposal. For the calculation

1) EU bathing water directive (Directive2006/7/EC)1) German guidelines for greywaterrecycling.

esu ts an

An important aspect for non-potablewater use in buildings is the hygienicquality. Quality standards for greywaterrecycling are given by FBR (2005). Thegiven suggestions are a combination ofthe microbiological standards of theGerman drinking water regulation andthe European guidelines for the quality ofbathing water (Directive 2006/7/EC). Therequirements of the different regulations,

Greywater treatment The median influent nutrient ratio ofCOD: N: P= 5:1:1 was unfavourable forthe biological community compared to

the optimum value of 100:20:1 (Metcalfand Eddy, 1991) due to the high dilutionrate by the circulation (average 1:10).Also, the organics and nutrientconcentrations were very low incomparison to usually reported values forgreywater in central Europe (FBR, 2005).

40 % of the analysed CW effluent samplesreached the quality standards of the EUbathing water quality directive and thehalf reached standards suggested by FBR(2005). Comparable results for other CWshave been reported and the need forsubsequent disinfection was statedelsewhere (Li et al., 2009; Reinoso et al.2008). The standards for irrigation waterquality given by OEWAV A011 and DIN19650 were reached by 50% and 80% ofthe monthly samples, respectively. Thequality requirements for other than

microbiological parameters like organic

The 60% load reduction was obtainedfrom measurements - considering thementioned dilution rate one canestimate a maximum BOD removal of85% from incoming raw and undilutedgreywater. The nutrient content remainedmore or less unchanged. Having in mindthat CWs may easily reach more than 95% of BOD removal in wastewatertreatment (Haberl and Pressl, 2005)these results are unsatisfying. Thephosphorus load was observed to beexceptionally high compared toliterature values (Li et al., 2009) thereason could be the use of industrialcleaning agents containing phosphates.

The high hydraulic loading resulted inperiodic blocking of the filter media andvery low nitrification (median of

Beside the maintenance efforts forcleaning the screening and pre-treatmentof the indoor CW, the operator is satisfiedwith the systems operation so far.Additional efforts arise occasionally bythe algae bloom in the outdoor water

Rainwater harvesting The quantitative measurementsshowed that about 25% of the yearly

non-potable water consumption wascovered by rainwater. Due to the coldweather conditions during December and


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Greywater reuse in office building - AustriaGre water reuse in office buildin -

Table 2: Summary of microbiologicalparameters suggested for different

conferences and meetin s, the

greywater productionwas

increased upto 2300 L/d.The

monthly averages ofthe dailywater

Parameter Bathing water Non-potable water Irrigation water

1) EU-Dir. 2) FBR 3) OEWAVA011

4) DIN 19650

E. Coli /100ml


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As mentioned above, water savingmeasures have been considered forscenarios (a) withand scenarios (b)without water saving

Table 3: Comparison of the costs and thewater saving potentials of the differentwater use scenarios (life span 25 years, re-

The capital valuerepresents the totalproject costs at thestart ofoperation. Financialbenefits due to

lowerwater supply anddisposalfees are included in

theoperatingcosts. Theresults in Table 3

show

that theconventionalsolution is not the

Scenarios Investments Re-

Investments

Operatin

g costs/a

Drinkingwater

demandm3/a

Capital

value

0 a-Convention 9,100 1,500 1,500 145 36,90

0 b-Convention 8,400 900 1,700 170 38,00

1 a-Combined 17,300 3,100 2,200 62 47,40

1 b-Combined 16,600 2,500 2,200 62 43,40

2 a-Greywater 16,740 3,100 2,300 73 49,10

2 b-Greywater 16,000 2,500 2,400 104 52,00

3 a-Rainwater 13,750 2,500 1,200 83 28,80

3 b-Rainwater 13,000 1,920 1,200 88 25,90

relatively high personal costs foroperation and maintenance. The lowoperating costs and medium investmentcosts lead to the good result forrainwater harvesting. Energy costs forpumping are relatively high whencirculation of rainwater or treatedgreywater is necessary but low incomparison to labour costs formaintenance. Nevertheless, energy

Further, the results indicate thatgreywater reuse only or rainwaterharvesting only result in a higher drinkingwater demand and lower water savingpotential. The influence of the watersaving measures is evident for thescenarios 0 and 2. The influence onscenario 3 is relatively low, because thewater saving measured impact thedrinking water demand only in monthswithout sufficient rainfall (winter months

in Austria). The existing system showedthe highest potential for water saving.Only about one third of the conventionalscenario was consumed. The capitalvalue of the installed system is more than20,000 higher than the cheapestscenario (rainwater harvesting). For thecomparison of scenarios for decisionmaking it is necessary to include non-

ConclusionsSummarizing the main results from

above, the following conclusions can be

- The removal performance of theindoor greywater treatment systemin terms of organic matter andnutrients was below the reportedperformance of other comparablesystems, but the required quality ofthe mixed non-potable water for thephysico-chemical parameters wassuff icient according to variousguidelines. The required reduction ofmicrobiological parameters couldnot be ensured for all operatingconditions.

- The aesthetics of the non-potablewater was sufficient for all operatingconditions, the use of mixedgreywater and rainwater did notlead to any disorders over fiveyears of operation.

- It was shown that the combinedsystem of water saving, greywaterreuse and rainwater harvesting leadsto the highest fresh water savings.

The existing combination allows afreshwater consumption of only onethird of a conventional system.

- A comparison of the capital costsof the existing combined system tothree additional water use scenariosshows that the existing system ismore expensive than rainwaterharvesting but cheaper thangreywater reuse only. The difference

Within five years of practicalexperience, the system fulfilled theexpectations of the operator of this multistorey office building Drawbacks are the


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Greywater reuse in office building - AustriaGre water reuse in office buildin -

system due to the circulation and therelated adverse influence on thetreatment performance and filterpermeability. Dilution and intensivecirculation over the constructed wetland

AcknowledgementsThis work has been funded by the AustrianFederal Ministry of Agriculture, Forestry,Environment and Water Management(BMLFUW) within the project SustainableSanitation Practical Application

ReferencesAsano T. (2007): Milestones in the reuse of

municipal wastewater. Proceedings of watersupply and sanitation for all, Berching, Germany,

pp.295-306.Eriksson E., Andersen H.R., Toke S. Madsen T.S, Ledin

A. (2009): Greywater pollution variability andloadings. Ecological Engineering 35, 661669.

FBR (2005): Hinweisblatt 2005 GrauwasserRecycling. Planungsgrundlagen undBetriebshinweise. Fachvereinigung Betriebs undRegenwassernutzung, Darmstadt, Germany [inGerman].

LAWA (2005): Leitlinien zur Durchfhrungdynamischer Kostenvergleichsrechnungen (KVR-Leitlinien). Lnderarbeitsgemeinschaft Wasser,Berlin, Germany.

Li F., Wichmann K., Otterpohl R. (2009): Reviewof the technological approaches for grey water

treatment and reuses. Science of the TotalEnvironment407, 34393449.

Knerr H, Engelhart, Hansen J, Sagawe G. (2008):Separated grey- and blackwater treatment by theKOMPLETT water recycling system a possibilityto close domestic water cycle. Proceeding ofSanitation Challenge: New Sanitation Conceptsand Models of Governance, Wageningen, TheNetherlands, pp.260-269.

Metcalf and Eddy, Inc (1991): Wastewaterengineering

treatment, disposal and reuse. In: TchobanoglousG, Burton

FL, editors. McGraw-Hill series in waterresources and

environmental engineering. 3rd edition. New York,USA.

Nolde E. (1999): Greywater reuse systems for toiletflushing in multi-storey buildings over ten yearsexperience in Berlin. Urban Water 1, 27584.

Name: Norbert WeissenbacherOrganisation: University of Natural

Resources and Applied Life Sciences,Vienna; Institute for SanitaryEngineering and Water PollutionControl

Town, Country: Vienna, Austria

Name: Elke MlleggerOrganisation: EcoSan


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overall project:


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Household greywater treatment for

peri-urban areas of Nakuru

Municipality, KenyaWithin the EU funded ROSA-project (Resource orientedSanitation concepts in peri-urban areas in Africa) differentgreywater treatment pilot systems were implemented and

assessed in Nakuru municipality.

Authors: J. Raude, B. Mutua, M. Chemelil, L. Kraft, K. Sleytr

AbstractWithin the EU funded project ROSA (Resource oriented Sanitation concepts in peri-urban areas in Africa) a baseline survey was carried out to asses the current greywaterdisposal situation, the quantity and quality of greywater in the peri urban areas of

Nakuru, Kenya. It was found out that most of the produced greywater is not used, notreused and not treated although contaminated with nutrients and bacteria. Thereforethere is a big demand for adequate treatment systems which are implemented within the

IntroductionAround the entire world, insufficient accessto safe water and basic sanitation has ledto more deaths than in military conflicts.According to estimates by UNDP (2006),for every single minute, over 3 childrenlose their lives due to diseases related to

unsafe water and poor sanitation. TheWorld Health Organization (WHO)attributes 13-17% mortality from diarrhoeafor children less than 5 years of age. Safewater and basic sanitation must beregarded as a basic human right and shouldtherefore be accessible and affordable to all(MWI, 2007). To achieve the UN MillenniumDevelopment Goals (MDGs) and thenational strategy in the Economic RecoveryStrategy for Wealth and EmploymentCreation (ERS-WEC), it is important toaddress sanitation challenges in urban and

periurban areas. Kenya faces seriouschallenges with regard to water andsanitation services. Despite the efforts ofinvestments provided in the past yearsby the government and developmentpartners, existing facilities have continuedto deteriorate and have also failed tomeet the demand of the equallyincreasing population (MWI, 2007). Thesechallenges are particularly severe in

(MWI, 2007), many unplanned structuresstillcontinue to be built.Greywater (wastewater stream fromkitchen, laundry, sinks, bath-tubs andshowers) produced by the average

household is the largest in volume.When freshly released, it contains arelatively lower number of potentiallyharmful compounds. Consequently, it isoften discharged untreated into awatercourse or any available empty spaceunder the assumption that seriousdamage might not result. Thesepractices however present potential risksof transmission of a large number ofwater-related diseases. Hence, there isneed for proper management of aquaticresources and also of the

pollutants. A sensible managementstrategyinvolves analysis of the composition ofgreywaterand creating a barrier throughquality

Current situation in NakuruNakuru municipality in Kenya, wherecentralised sewerage connection isinadequate, faces a serious challenge ofsustainable access to safe wastewaterdisposal in the unplanned settlements.


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Household re water treatment -

in-situ separation of domesticwastewater in various streams (grey,yellow, beige, brown and black water)at the source of generation andhandling each stream individually. Beigewater is anal cleansing water; yellow

water is wastewater stream made up ofurine and flush water. Black water is acombination of brown and yellow waterwhich is also referred to as night soil whilebrown water is wastewater streamcomposed of faecesand flush water. Source separation allowsfor adequate treatment of differentwastewater flows according to theircharacteristics.The generated amount of greywater isinfluenced by factors such as existing

water supply services andinfrastructure, number of householdmembers, age distribution, lifestylecharacteristics etc. (Morel and Diener,2006). It greatly varies as a function ofthese dynamics of the households.

Figure 1: Greywater disposal to stormwater drain in Nakuru

Table 1: Calculated amount ofproduced greywater per

ownership and acceptance by thehousehold is a key to sustainablegreywa ter treatment. Decentralizedwastewater treatment systems range insize from individual on-site systemsserving one household to shared facilitiesserving about 40 households or publicfacilities for several households sharingone sanitary facility. However,thereis need to develop different

treatmentoptions tooffer technical solutions in orderto

reduce health and environmental risks asa resultof domestic greywater pollution. Thiswork proposed promoting resources-oriented sanitation, where availablenutrients in the effluent can be utilized

Samplingarea

Daily water use[l/d]

Greywaterproduced

Kaptembwo 85 64

Kwa Rhonda 90 67Mwariki 97 72

Lake View 77 57

disposegreywater inseptic tanks andpit-latrines (29%) as presentedin Figure 2. As a

result, most pit-latrines emitfoul smell and

arefu ll of fl ie s.However,though to alimited extend(3 %) greywateris reused forcleaningpit-latrines thus

practice has resulted in a majorenvironmental and public health concernto the residents. The choice of

80

7066.9

60

50

4029

30

20

10 3 1.1

0

Empty space Septic/Pit-latrine Cleaning Pit-latrine Others

Disposal Method

Figure 2: Main greywater disposalpractice in the investigated areas of


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culturally acceptable systems that aimat closing the natural nutrient and watercycle. This can be achieved through bestsanitation management practices aimedat improving public health and generalenvironment. Since good hygiene and

adequate sanitation are pre-requisites forgood health, safe disposal or reuse ofgreywater can be asolution to achieving good hygiene.Population density however presents itselfas a challenge since sanitation relatedhealth risks are high in denselypopulated urban areas. Furthermore,the unplanned settlement structures,like most of the peri urban areas inhibitthe integration of sanitation systems.As a result, sewerage

connections become technicallyimpossible to construct and sometimesto operate leading to current greywaterdisposal methods in use that involveemptying in any available open spaceincluding roads and foot paths. For safe

nitrogen (NH4-N), nitrate-nitrogen (NO3-N),nitrite-nitrogen (NO2-N)and FaecalColiforms (FC) of 59 greywater samples(24 samples from kitchen, 25 samplesfrom laundry, 10 samples from combinedgreywater and additional five source

water samples). All methods used for thegreywater analyses were according tothe Manual for Water Quality Analysis,

Table 2: Summary of the greywaterand source water characteristics(median values) (Kraft, 2009)

Parameter Unit Kitchen Laundry Combined Sou

Amount l/d 5.5 56 65.5 87.

Temperature C 20.7 20.0 18.3 23.

pH 8.1 9.4 8.4 7.0

DO mg/l 2.17 3.98 1.16 3.5

BOD5 mg/l 445 449 455 13

EC S/cm 974 1365 1247 323

Salinity g/l 0.45 0.50 0.55 0.2

TDS mg/l 800 993 981 223

TSS mg/l 1255 1090 775 2.0

Org. content mg/l 1200 870 545 1.6

Inorg. content mg/l 80 260 220 n.

TP mg/l 7.59 9.02 8.28 0.0

SRP mg/l 3.82 2.77 4.96 0.0

NH4-N mg/l 2.13 5.29 7.32 n.

NO3-N mg/l 3.68 2.44 1.97 3.4

NO2-N mg/l 2.63 8.61 2.71 n.

FC logcfu/

7.05 5.49 7.04 1.1

n. . ..notFi ure 3: Lake View

To address this problem a horizontal-

sub-surfaceflow constructed wetland (HSSF CW) wasestablished at Lake View and CraterView Secondary School through thesupport of ROSA project (Langergraberet al, 2008). Within this project a surveyto identify and characterisegreywater generation and disposal habitsinNakuru provided the basis for designingandimplementing resource-orientedgreywater treatment systems. In Table 2

the mean values for the following physico-chemical and bacteriological parametersare given: Temperature, pH, Dissolved

Piloting area- NakuruMunicipalityNakuru municipality is on the floor ofGreat Eastern branch of the Rift Valleyand the fourth largest city in Kenya. It isalso the administrative headquarters ofRift Valley province and a hub of theprovinces commercial activities. The townlies between latitude 0 10 and 0 20South and longitude 36 10 East and at1859 m above sea level (MCN et al.,1999). It covers an area of 290 km ofwhich Nakuru National park takes 188

km leaving 102 km to town functions.


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Household greywater treatment - NakuruHousehold re water treatment -

Figure 4: Greywaterdisposal in Nakuru

Fi ure 5 Gre water dis osal in Nakuru Fi ure 6: Gre water

thus exerting pressure on existingwater and wastewater management

below the ground level. To sensitize awider group from Nakuru Municipality,the pilots were established at oneresidential area (Lake View) and a

Implementation of greywater treatmentoptionsResults from Table 1 and Table 2 were used asa guide in developing site specific greywaterquality improvement systems ideal for the highdensity population, low income peri-urbansettlements. Table 3 presents some of theconsiderations in design and construction ofthe HSSF CW system at Crater View Secondary

School and Lake View residential area. Thedesign of the wetland was based on the rule ofthumb such as the Austrian and Germandesign standards (NORM B 2505, 2008, andDIN A-262, 2006, respectively) withoutconsidering and quantifying the processesoccurring inside such filters in detail. Morerecently, however, efforts have been made tounderstand and quantify processes in pilotfacilities (Langergraber, 2008). To avoid creatinganother environmental problem in form ofmalaria mosquito breeding sites, horizontal

Development of a greywater treatmentsystem involved consideration ofinstitutional and social issues in additionto technical factors. These issuesinfluenced controlled decision makingduring the planning and preliminarydesign stages. Also, it involved using aguide to project development afterReeds et al. (1995) involving

characterization of greywater bydefining the volume and composition tobe treated. Concept feasibility which

Table 3: Desi n

No Name Description1 Pre-treatment Two chamber ( 0.25 & 0.75 m) litter trap, coarse organic matter;

grease trap ofcleaning interval not more than 4 times/yr

2 Surface area Horizontal sub-surface flow constructed wetland (HSSF CW); length =2m, width = 1m3 Inlet Stone distributor; slotted pipe for greywater distribution, inlet depth =0.86m4 Treatment volume Fine gravel (D60 = 3.5mm, Cu = 1.8); initial porosity = 40%; with an

7 Otherdesign

bottom slo e of 1-2%; ravel media; eo membrane liner of

8 Filter material Building sand cheap and locally available (3-8mm grain-size)9 Plants Vetiver grass ( Vetiveria zizanioides)10 R i i 2 d


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Household greywater treatment - Nakuru

Figure 7: Washing facility- CraterView Secondary School

The general reaction from the schoolcommunity was positive though withsome disappointments. They had a veryhigh expectation of using the effluentfor irrigation in the school kitchen gardenbut due to its high bacterialcontamination the outf low of thepilot system could not berecommended for save use. Inconsecutive studies it is planned to adapt

Figure 8: James and Laura sampling at the HSSF CWs

ConclusionBased on these results and furtherpiloting, HSSF CWs are a promisingtechnology in urban and periurban areasthat are not served by the central sewersystem. Within Nakuru municipality,

many poor households are unable toaccess wastewater collection, transportand treatment services that could savethe lives of children and adults fromwater related ailments. Unless theseservices reach the poorest, universalcoverage will not be achieved. Newsanitation policies and initiatives oftenpay little attention to the greywaterhandling systems. Population growth andurbanization are a major challenge andpresent themselves as themain obstacle in integrating sanitation inthese settlements. Meanwhile, urbanresidents continue to suffer from poorsanitation. High child mortality due topoor hygienic conditions is a harshillustration of the inequalities in society.Generally, problems of poverty areinextricably linked with those of water; itsavailability, proximity, quantityand quality. The

combination of safe drinkingwater and hygienic sanitation facilities aspresented in this case of household

based greywater treatment is a pre-condition for good health and success inthe fight against poverty, hunger, childdeaths and gender inequality. This is alsoone way of unlocking the billions ofpeoplelocked in the c cle of overt and

Results and discussionThe removal rates of the HSSF CW based

on an average percentage pollutantreduction are presented in Table 4:BOD5 99.7%, TSS 97%, TP 88.%, NH4 -N 97% and F C 18% . Sampl ingcommenced four months later after theplants had established. This greywatertreatment system was designed with aretention period of less than 48 hours inthe settling tank. However, water flowfrom a nearby borehole through thewashing facility was highly variable.The variability was caused by pumpingpower fluctuations as a result of

blackouts and power rationing affectingthe entire country. Low electricity outputoccasioned by low water levels in thehydro-power stations influenced thesystems. Consequently, greywater turnedseptic due to longer storage periods inthe settling tanks. A fence had to be builtaround the site to avoid possible health

Table 4: Results from influent effluentlaborator sam le anal sis

Parameter EC Salinity DO TDS BOD5 TSS TP FC NH4+

Units S/cm g/l mg/l mg/l mg/l mg/l mg/l Log 10 mg/lInfluent 1929 1.0 3.01 1257 104.0 255 2.43 4.97 3.17Effluent 1644 0.8 0.08 1084 0.33 9 0.29 4.09 0.09


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Household greywater treatment - Nakuru

AcknowledgementsThe work is carried out within the projectROSA (Resource-Oriented Sanitationconcepts for periurban areas in Africa;Contract No. 037025-GOCE; duration:1.10.2006 31.3.2010), a Specific Target

REsearch Project (STREP) funded within theEU 6th Framework Programme, Sub-priority "Global Change andEcosystems". The authors are grateful forthe support.

ReferencesDWA-A 262 (2006): Grundstze fr Bemessung, Bau

und Betrieb von Pflanzenklranlagen mitbepflanzten Bodenfiltern zur biologischen

Reinigung kommunalenAbwassers.Arbeitsblatt, DWA - Deutsche Vereinigung frWasserwirtschaft, Abwasserund Abfall e. V.,Hennef,Germany [in German].

Kraft, L. (2009): Characterisation of Greywater fromperi-urban areas in Nakuru, Kenya. Mastertheses; BOKU University, Vienna, Austria.

Langergraber, G. (2008): Modeling of Processes insubsurface flow constructed wetlands- A review.Vadoze Zone Journal 7(2), 830-842.

Langergraber, G., Meinzinger, F., Lechner, M., deBrujne, G., Sugden, S., Niwagaba, C.B., Mashauri,D., Mutua, B.M., Teklemariam, A., Achiro, I., Kiarie,S.C., Laizer, J.T., Ayele, W. (2008): The ROSAproject A new approach to sustainable sanitationin Eastern African cities. Proceedings of the 6thIWA World Water Congress, 8-12 September 2008,Vienna, Austria. (CD-ROM, paper 664279)

MCN, (1999): Municipal Council Nakuru StrategicStructure Plan. Action Plan for SustainableUrban Development of Nakuru town and itsEnvirons, Volume 1. GoK, Nakuru, Kenya.

Morel A. and Diener, S. (2006): GreywaterManagement in Low and Middle-Income Countries,Review of different treatment systems forhouseholds or neighbourhoods. Sandec (SwissFederal Institute of Aquatic Science and Technology(Eawag): Dbendorf, Switzerland.

MWI (2007): Ministry of Water and Irrigation.Awareness

Raising and Marketing Strategies. AcceleratingAccess toSanitation. East AfricanRegional Conference, 27-28November 2007, Nairobi, Kenya.

Odour, S.O. (2008): Manual for Water QualityAnalysis. Egerton University, Njoro, Kenya

NORM B 2505 (2005): Bepf lanzteB od en fi lt er (Pflanzenklranlagen) Anwendung, Bemessung, Bau und Betrieb(Subsurface-flow constructed wetlands Application,dimensioning, installation and operation).sterreichisches Normungsinstitut, Vienna, Austria[in German].

Reed, S.C; Crites, R. W; and Middlebrooks, E.J (1995):Natural systems for waste management andtreatment. McGraw-Hill, New York, USA.

UNDP (2006): United Nations DevelopmentProgram, Environment and Energy.http://www.undp.org/water (last access:01.10.2009).

Name:James Raude,Benedict Mutua,Mathew Chemelil

Organisation: Departmentof Agricultural

Engineering, Egerton UniversityTown, Country: Egerton, Kenyae-mail:

[email protected]

Name: Laura Kraft,Kirsten Sleytr

Organisation: University of NaturalResources and Applied Life Sciences,Vienna; Institute for SanitaryEngineering and Water PollutionControl

Town, Country: Vienna, Austria

e-mail:
http://www.undp.org/waterhttp://www.undp.org/watermailto:[email protected]:[email protected]:[email protected],mailto:[email protected],mailto:[email protected],mailto:[email protected],http://www.undp.org/watermailto:[email protected]:[email protected]:[email protected]:[email protected],mailto:[email protected],


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Greywater use in peri-urban households

Kitgum, UgandaAuthors: R. Kulabako, J. Kinobe, J. Mujunga, S. Olwenyi, K. S

Technical detail:

greywater tower gardens; poles (wooden, iron bars or fence posts) and shadingmaterial surrounding the soil and a central stone-packed drain; vegetables (e.g.tomatoes, spinach) are planted into slits of the shading material in the soil;

AbstractIn this study, undertaken within the ROSA project (Resource oriented Sanitation conceptsin peri-urban areas in Africa), an understanding of greywater characteristics is createdto demonstrate a low cost reuse option involving direct application of untreatedgreywater to small so called greywater towers at household level in peri-urbansettlements in Kitgum Town Council. It can be concluded that greywater towers provide a

IntroductionUrbanization in cities of the developingworld like Uganda is virtuallysynonymous with formation of densehuman settlements inhabited by thepoor, lack of adequate safe drinkingwater, lack or inadequate sanitation

(excreta, greywater andsolid waste) and generally a degradedenvironment. The high populationsliving under such conditions are subjectto health risks. With the increasingdemand for freshwater, it is of paramountimportance that water consumption shiftstowards one, which promotesconsumptionof adequate amounts of water

of acceptablequality. However, this shift requires thatalternative sources of water areidentified.Experiences elsewhere in the world

includingseveral arid and semi-arid countriesindicates thatgreywater can be a cost effectivealternative source of water (Morel and

Diener, 2006). Greywater is watercoming from cloth washers, bathtubs,showers, kitchen sinks and dishwashersand comprises between 50 to 80% ofresidential wastewater (Al-Jayyousi,2003).Governments allocatesubstantial amountsofmoney to develop, treat and transportwaterresources. On the other hand more

connected to the sewerage system withthe majority using on-site sanitationsystems while in Kitgum Town Council(KTC), a semi-arid town in NorthernUganda, on-site sanitation systemspredominate (ROSA, 2007).In the peri-urban areas of Kitgum town likein most cities of developing countries,greywater is disposed of, untreated ontothe ground and into open storm waterdrains. The unsanitary disposal results increation of malaria mosquito breeding

grounds, smelly stagnant waters, childrenfalling ill after playing in the wastewater,etc. (ROSA, 2007). The majority of thecommunities in the peri-urban settlementsof KTC do not reuse the greywater and yetfrequently experience water supplyshortages following power outages(pumping from the central watersupply stalls) and have an inadequatenumber of boreholes (ROSA, 2007).According to Imhof and Muhlemann(2005), the main barrier for wider and

faster dissemination of suitablegreywater management systems athousehold level in the developingcountries, is the lack of knowledge andexperience. Scientific knowledge issparse regarding greywatercharacteristics allowing its reuse. This


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Household greywater use-

BackgroundThe project ROSA (Resource-OrientedSanitation concepts for peri-urban areas in Africa,Langergraberet al., 2008) promotesresource-oriented sanitation concepts as a route tosustainable and ecological soundsanitation in order to meet the UNMillennium Development Goals (MDGs).The project is undertaken in fourpilot cities in East Africa namely ArbaMinch (Ethiopia), Nakuru (Kenya), Arusha(Tanzania) and Kitgum (Uganda). Thesecities have a population from several10,000 up to 500,000 inhabitants andshare common problems, e.g. they aresituated in rather dry regions resulting in

lack of water, have relatively highpopulation growth rates and poorsanitation facilities, if available at all.Kitgum district is located in NorthernUganda, 452 km from Kampala. Thedistrict has experienced civil warcharacterized with death, abduction, rape,and destruction of socialinfrastructures anddisplacementof the people for the last

twodecades. As a result of this instability, poor

sanitation and lack of safe water are the

could lack cement and/or not plasteredand, and iii) low class: households withgrass thatched were selected. Theselected households were sensitized onhow greywater could be utilised throughagriculture and the associated potential

Figure 1 Sensitisation of thehouseholds by the research team

For greywater treatment the technologyof greywater towers (as described inCrosby, 2005) was selected as it is asimple, innovative system, which usesgreywater for growing vegetables on a

small footprint (


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a

e f g h

i j k

Fi ure 2 Settin u of a tower arden at one of the

The back fill consisted of a mixture ofthree parts of soil, two parts of animalmanure and one part of ash to providefacility. The different parts weremeasured out by volume using abucket (Figure 2d). The backfill was

then well mixed before applying it(Figure 2e). A bucket with its bottomremoved was placed at the bottom in themiddle of the tower (Figure 2f). Stoneswere carefully packed in the bucket insuch a way that did not permit fast flowof the water through (Figure 2g). Thesides of the bucket were back filled withthe soil mixture (Figure 2h). The bucketwas then partially pulled out leaving thestones in position. The bucket was

was applied on a daily basis. On averageeach greywater tower could receiveabout 3 litres of greywater per day.Over the weekend, the greywatertowers were splashed with 2 buckets(about 10litres) of clean water to washaway the soap. Selected vegetables suchas tomatoes and onions were planted onthe greywater towers. The control towergarden received about 3 litres of

Operation of the greywater towersGreywater towers were operated in sucha way that greywater from the

Greywater sample collection andanalysisSamples were collected from 6households every two to three weeksfrom 3 greywater streams (kitchen,laundry and bathroom) for a period of 6months. Physico-chemical andbacteriological analyses of the greywater

were determined for the selectedparameters: pH, Dissolved Oxygen (DO),Electrical conductivity (EC), Temperature,


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Household greywater use- KitgumHousehold greywater use-

Phosphorus, Total Phosphorus, SodiumAdsorption Ratio (SAR) and E. Coli. Theparameters pH, DO, EC and Temperaturewere determined in-situ using a calibrated

multi-parameter meter(Quanta-

Hydrolab). Samples for physico-chemicaland

bacteriological analyses were collectedin acid rinsed and steriled bottlesrespectively, stored in a cool box at 4oCand transported for analysis to the

Public Health and EnvironmentalEngineering

Laboratory at Makerere University inKampala.

Prior to the analysis for ortho andtotal phosphorus, and ammonia nitrogen.

The samples were filtered through a 1.2m Whatman glassmicrofibre filter paper (GF/C). COD wasdetermined using the Closed

Reflux, Titrimetricmethod (APHA/AWWA/WEF, 1998). BOD5was determined by pressure differencewithin a closed system (BOD5 CW7000direct reading apparatus) according tothe instrument manual. Totalphosphorus was determined using theascorbic acid method with persulfate

digestion while Ortho phosphorus wasmeasured using the ascorbic acidmethod (APHA/AWWF/WEF, 1998). NH3-N

Plant measurements To assess the impact of greywaterapplication on plant growth,measurements at two households withgreywater towers and the control weretaken. This involved measurements of

stems, leaves, number of seeds, number

Resul

Greywater reuseA review of the baseline study report(ROSA, 2007) indicated that there was nogreywater reuse in the study area. Thegenerated greywater is either disposed ofin open places (68%) and or openchannels traversing the area and wherepossible, in soak pits by 21% of thehouseholds (ROSA, 2007). These findingswere corroborated by the interviewfindings in this study with the majority ofthe respondent households, 61% and 76%disposing of kitchen and laundrywastewater respectively on the ground.Most of the respondent households (71%)discharge their bathroom wastewaterintosoak pi ts. Interestingly, a fewrespondent households (11%) pourtheir kitchen greywater into thegardens. Interviews with the localsindicated that they were not aware ofany greywater disposal best practicesbut expressed willingness to reuse

Soil sample collection and analysis To ascertain the impact of thegreywater on the soils, soil sampleswere collected at each householdinitially prior to greywater applicationand analyzed for pH, organic mattercontent, nitrogen, phosphorus andpotassium. After the application ofgreywater, soil samples from thegreywater towers were later picked on amonthly basis for a period of 3 months andanalysed for the same parameters at theSoil Science Laboratory at MakerereUniversity, Kampala, according toanalytical techniques in Okalebo (2002).pH was measured using the electrodemethod in a soil-water suspension using a1:2.5 (w/v) ratio, organic matterdetermination was according to theWalkley and Black Method, Total nitrogenwas analysed using the Kjeldahl

method, potassium was determined byflame photometry method while

Amount of greywater produced

The generation of grey water byhouseholds is directly related to theconsumption of water. Of the 38households interviewed, the majority(63%) use 3 to 5 jerrycans of waterdaily for domestic cores includingdrinking. Given that each jerrycan holds20 liters, about 60 to 80 liters of waterare used daily for washing kitchenutensils, laundry, bathing and drinking byeach household. Since no wastewaterenters the sewers in Paradwong parish inKTC, the quantity of greywater generateddaily per household may be estimated tobe 80% of the water consumption(Punimia, 1998). This means thatapproximately 48 to 64 liters of grey waterare being produced on a daily basis byeach household in Ktigum town council.As a result of the water scarcity in theregion the quantity of greywaterproduced is low. The greywater qualitygenerated by these households is


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Physicochemical characteristics ofthe greywaterThe characteristics of the greywater fromthe different sources (n=35) arepresented in Figure 3. The results depictsome variation of the measured

parameters between source types. Thegreywateris moderately alkaline with the laundrywater having pH values that fall outsidethe effluent discharge standards (i.e. 6-8,NEMA 1999) but is in line with the rangeobserved elsewhere (i.e. 8-10, Erikssonet al., 2002). The high pH values of thelaundry water may be due to the alkalinityof the detergents and or soaps that areused (ChristovaBoal et al., 1996).However, given the pH range forother greywater types, the alkalinity of

thefreshwater used in the area which isprimarily groundwater, may also beimportant (ROSA, 2007). The SAR ishigher in laundry water followed bybathroom and kitchen water in thatorder. The high laundry SAR values maybe a result of the type of detergents orsoaps used. Long term application ofwater with a high SAR can be detrimental tothe hydraulic conductivity and physicalproperties of soils and associated plant

systems (Wiel-Shafran etal., 2006). Most commerciallyavailable

bathroom/laundry products are currentlymanufactured using various types andquantities of sodium salts. Hence giventhe SAR values of the greywatervalidates the need to apply freshwaterto the greywater towers as a controlmeasure against soil damage (clogging).The temperature is relatively highest forbathroom waters with the kitchen andlaundry waters having almost similar

average values. The probableexplanation for this discrepancy is thatwaters for bathing purposes particularlyin the mornings are warmed up. All thegreywater source types exhibit highturbidity, with mean values greater thanthe stipulated national effluent dischargestandard (i.e. >100 NTU, NEMA 1999). The laundry waters have the highestturbidity most likely due to more soapuse compared to that in the kitchen andbathroom. During sample analysis thelaundry greywater was blue in colour with

a cloudy appearance which was thought toresult from more soap use. Turbidity inthese wastewaters may also be related to

types follows a similar trend to that ofelectrical conductivity with laundryexhibiting higher values (Figure 3).All the greywater sources have meanphosphorus levels with in the nationaleffluent discharge standards (i.e. < 5

and 10 mg/l for Ortho and Total-P,respectively) as indicated in Figure 3. Thetotal phosphorus levels indicate thatphosphorus containing detergents areused (i.e. > 3mg/l, WHO, 2006). Despitethis, phosphorus when disposed to thegreywater tower is not a problem since itis a plant nutrient. However, problemsmay accrue if the soils becomephosphate saturated resulting in leachingto the groundwater and or to run-off to asurface water source. The ammonia

nitrogen levels for the greywater obtainedhere, are higher than values cited in otherstudies in the developed countries withthe greywater in these cases consideredlight (Birks and Hills, 2007; Eriksson etal., 2002). The greywater types exhibit high meanBOD5 and COD values well above thenational effluent discharge standards(i.e . >30 mg BOD5/l and 100 mg

Bacteriological characteristics of

greywaterE.coli were used to characterize thebacteriological quality of the greywaterfrom the 3 sources. There was not muchvariation in the E.coli results for thedifferent greywater source types withthe bathroom greywater having lessE.coli counts compared to the other 2sources (Table 1). The bacteriologicalcounts of the greywater sources is similarto that of raw sewage as observed forgreywater discharging from informalsettlements (Carden et al., 2007). The

high E.coli counts exhibited in thekitchen greywater may be due to thesources of water used which are mainlyopen streams and waters from RiverPager, given the limited availability ofboreholes. According to a water qualitysurvey by Oxfam, EnvironmentalResearchers and KTC HealthDepartment and Water Sector inanuary 2007, sampled streams and

rivers had E. Coli counts of 100


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Figure 3 Characteristics of greywater from different sources inKitgum Town Council (bars represent mean values standard

Table 1 Bacteriological quality(E.Coli) of the greywater sourcetypes (n = 8; Log 10 E.coli/100

mg/kg, Landon, 1991) and low nitrogen,potassium and organic matter. Thephosphate decrease in the soils followinggreywater application may be attributedto plant uptake as indicated by thehealthy appearance of these (Figure 4).Despite the high ammonia-nitrogenlevels in the greywater (Figure 3), thenitrogen content in the soils

bfollowing greywater application arehardly affected. This may beattributed to uptake by plants and alsoto a less degree the relatively high pH

Greywater Average RangeKitchen 8.42


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Table 2 Soil chemical characteristics at thestudy households prior to and after applicationof greywater (Average valuesSD; initial: n = 7;

Parameter Initial After

pH 9.060.85 8.790.66Nitrogen (%) 0.0860.021 0.0850.015

Phosphorus (mg/kg) 21.897.80 19.7920.82Potassium (meq/100g 2.520.90 2.220.83Organic matter (%) 1.610.53 1.550.42

Figure 4 (a) Growth of tomatoes (on top) andonions (in the sides (b) flowering of tomatoe

Paradwong village in Kitgum Town Council reveal thatthey currently haveknowledge of the greywatertower and would want tohave one at their homes. Awalk through the area,revealed fifteen additionalhouseholds that set upgreywater towers after seeingthe benefits associated withthe study units. Additionally,more households have set upsmall gardens of vegetableson their landand are applyinggreywater directly to theplants.Where vegetables have been

harvested from the greywatertowers, the households haveconverted the area into smallgardens irrigated withgreywater

Plant growth Observations andMeasurements The observations of the plantedvegetables are shown in Figure 4. Theobservations revealed healthy growth ofthe planted vegetables.Plant measurement results carried out

at 2 households (A & B) and controlgreywater towers are presented in Table3. The results show that the tomato andonion plants receiving greywater athousehold B generally performed wellcompared to those that received thegroundwater (control). The relativelylower performance by the plants in thegreywater towers at household A mayhave been a result of the poor operation.

from laundry since 1) many of thehouseholds do not wash their clothes on adaily basis and 2) the general water

Figure. 5 Area around greywatertowers used as a small garden and

Community perceptions andchallenges to greywater reuseusing greywater towers

a e an

used was attacked by roaming animals

in the area and tore within twomonths. Here, some protection fenceshad to be installed around the

greywater towers. The plantedvegetables

Control A B

Tomatoes

Length of 1st Stem (cm) 3 3 3.4Length of 1st leaf (cm) 43.3 27.2 37.5Length of leaflet (cm) 10.4 8 11.7No of flowers 16 7 18No of seeds 1 5 5Length of inter-node (cm) 14.5 17.2 18No of branches 4 4 7

OnionsNo of leaves 9 10 8Length of leaf (cm) 8.7 15 19

Conclusions- Greywater is poorly

managed in Kitgum TownCouncil with the largestpopulation of the community(68%) pouring the greywater

onto the ground while 21%dispose their greywater intodrain channels and soak pits.


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- The main sources of greywater in thearea are laundry, bath areas andkitchen.

- Laundry water except fortemperature generally had thehighest mean values of the parameters

assessed followed by kitchen andbathroom greywater.

- The effect of greywater application onthe soil characteristics was notsignificant with respect topotassium, organic matter andnitrogen content. However there was aslight decrease in phosphorus

Recommendations- Given the greywater characteristics

presented in this study, greywatershould be properly managed toprevent contamination of theenvironment and disease prevalence.

- Given the positive response to theapplication of greywater in gardensin Kitgum Town Council, there isneed to increase sensitization of thecommunity people on greywaterreuse and associated benefits toscale up this reuse option.

- There is need for research to ascertainthe bacteriological quality of the

leafy crops to assure safety.- The hydraulic load of a greywatertower should be ascertained so asto guide the number of gardensneeded for a particular quantity of

AcknowledgementsThe work is carried out within the projectROSA (Resource-Oriented Sanitationconcepts for periurban areas in Africa;Contract No. 037025-GOCE; duration:1.10.2006 31.3.2010), a Specific Target

REsearch Project (STREP) funded within theEU 6th Framework Programme, Sub-priority "Global Change and

ReferencesAlit, W., Zeev, R., Noam, W., Eilon, A., Amit, G.

(2006). Potential changes in soil propertiesfollowing irrigation with surfactant-rich greywater.Ecological Engineering 26, 348-354.

Al-Jayyousi, O.R. (2003). Greywater reuse: towardssustainable management. Desalination 156, 181-192.

Armitage, N.P., Winter, K., Spiegel, A., Kruger, E.(2009). Community-focused greywater managementin two informal settlements in South Africa. WaterScience and Technology59(12): 2341-2350.

APHA/AWWA/WEF (1998): Standard methods for theexamination of water and wastewater. 20thedition, American Public Health Association, American Water Works Association, WaterEnvironment Federation Publication, Washington,D.C., USA.

Birks, R., Hills, S. (2007). Characterisation ofindicator organisms and pathogens in Domesticgreywater for recycling. Environmental MonitoringAssessment129, 61-69.

Carden, K., Armitage, N., Winter, K., Sichone, O.,Rivett, U., Kahonde, J. (2007). The use anddisposal of greywater in the non-sewered areas ofSouth Africa: paper 1-Quantifying the greywatergenerated and assessing its quality. Water SA33(4), 425-432.

Christova-Boal, D., Eden, R.E., McFarlane, S. (1996).An

investigation into greywater reusefor urban residential

properties. Desalination 106, 391-397.Crosby, C. (2005):Food from Used Water: Making the

Previously Impossible Happen. URL:http://www.dwaf.gov.za/Events/WaterWeek/2005/Docume nts/WaterWheelJan05d.pdf [Accessed on

31.03.2007].Eriksson, E., Auffarth, K., Henze, M., Ledin, A.(2002).

Characteristics of grey wastewater. Urban Water 4,85-104.

Imhof, B. and Muhlemann J. (2005). Greywatertreatment on household level in developingcountries-A state of the art review. Department ofEnvironmental Sciences at the Swiss FederalInstitute of Technology (ETH), Zrich, Switzerland.

Landon, J.R. (ed.) (1991). A Handbook for soilsurvey and agricultural land evaluation in thetropics and subtropics. Longman Scientific andTechnical Group Ltd, Hong Kong, PR China.

Langergraber, G., Meinzinger, F., Lechner, M., de

Brujne, G., Sugden, S., Niwagaba, C.B., Mashauri,D., Mutua, B.M., Teklemariam, A., Achiro, I., Kiarie,S.C., Laizer, J.T., Ayele, W. (2008): The ROSAproject A new approach to sustainable sanitationin Eastern African cities. Proceedings of the 6thIWA World Water Congress, 8-12 September 2008,Vienna, Austria. (CD-ROM, paper 664279)

Morel A. and Diener, S. (2006). GreywaterManagement in Low and Middle-IncomeCountries,Review of different treatment systemsfor households or neighbourhoods. Sandec(Swiss Federal Institute of Aquatic Science andTechnology (EAWAG), Dbendorf, Switzerland.

NEMA, (1999). Environmental standards andpreliminary environment impact assessment forwater quality and discharge of effluent intowater/land in Uganda. National EnvironmentManagement Authority, Kampala, Uganda.

Okalebo, R. (2002). Laboratory methods of soil and
http://www.dwaf.gov.za/Events/WaterWeek/2005/Documehttp://www.dwaf.gov.za/Events/WaterWeek/2005/Documehttp://www.dwaf.gov.za/Events/WaterWeek/2005/Documehttp://www.dwaf.gov.za/Events/WaterWeek/2005/Docume


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Wiel-Shafran, A., Ronen, Z., Weisbrod, N., Adar, E.,Gross, A. (2006). Potential changes in soilproperties followingirrigation with surfactant-rich greywater.

EcologicalEngineering 26, 348-354.

WHO (2006). WHO guidelines for the safe use ofwastewater, excreta and greywater, Volume IVExctreta and greywater use in agriculture. WorldHealth Organisation, Geneva, Switzerland.

Zimmo, O.R., van der Steen, N.P., Gijzen, H.J. (2003)Comparison of ammonia volatilisation rates inal ae and duckweed-based waste stabilisation

.

Name: R. Kulabako,J. Kinobe,J. Mujunga

S. OlwenyiOrganisation: Department of CivilEngineering, Makerere University

Town, Country: Kampala, Ugandae-mail:

[email protected],[email protected]

Name: K. SleytrOrganisation: University of Natural

Resources and Applied Life Sciences,

Vienna; Institute for SanitaryEngineering and Water PollutionControl
mailto:[email protected],mailto:[email protected],mailto:[email protected],mailto:[email protected]:[email protected],mailto:[email protected],mailto:[email protected],mailto:[email protected]:[email protected]:[email protected]:[email protected]:[email protected]


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overall project:

NASPA

Greywater treatment inapartment

stract with summary of technical datan apartment house with 9 apartments and a total of 14 inhabitants a separate greywaterction system, treatment and distribution plumbing was implemented as part of aprehensive water scheme also comprising water saving, rainwater harvesting, on-treatment of water and reuse for toilet flushing, landscape irrigation and

undwater recharge. The greywater is treated in a Pontos SBR, which includes UVfection and a storage tank. The treated water has a good quality for its intended purpose

oilet flushing. Compared with nationwide average supply and treatment volumes per

DescriptionA dilapidated complex of farmbuildings, comprising the farm house,the stable, a barn and other annexeswas to be refurbished andtransformed into apartments. The farmlies in Pllau in Styria in the South-East

of Austria, a hilly region with a mildclimate and a relatively even rainfalldistribution with an average rainfall of800 mm per year, average monthlyrainfall varying between 31 mm inJanuary and 126 mm in July (at Graz).The concept used for the refurbishmentof the apartment house (Pllau 18,Figure 1) aims at overall sustainability. This concept comprises constructionmaterials and construction physicsaspects, energy for heating and water. Theconcept extends to the surroundings of

the house with the plan to convert a

Figure 1: The

function room for events, a commonwine cellar and office space.As far as possible materials from thepreviously existing buildings, especiallybricks, were reused. The old structureswere rebuilt with adapted techniques,including the vaulted ceiling of thefunction room. Thorough insulation and

special windows adapted to thetraditional architecture but with tripleglazing ensure low energy demand andhigh quality of living conditions. The energy supply relies on 100 %renewable sources with a 42 kW (60 m )solar collector and a 50 kW wood chipboiler for space and water heating. Localfarmers provide the wood chips. Energycontained in greywater is also recycledinto the space heating system. A 17 m

photovoltaic system is generating part of


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Pilot system built in water rich Austria to reduce potable wate

consumption

Authors: M. Regelsberger, B. Regelsberger, C. Plat


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Greywater treatment in apartment

from the central heating room via a 2-conduit network and decentralised heattransfer stations in the apartments andother heat consumers. Despite therelative water richness auf the regionand Austria in general the owner also

wanted a sustainable water concept forthe complex, partly to match thesustainable energy concept, but also toreduce dependency on centralised supply

water if the rainwater is exhausted.Switching from one water source toanother is done automatically. The energycontained in the greywater is recycledinto the heating system via a cross flowstainless steel greywater heat exchanger

with a total surface of 2,60 m and acapacity of 28 l/min (ThermoCycle WGR355, Forstner Speichertechnik GmbH),which is approximately equivalent to 4

Water is supplied from three sources,the village water mains, rainwater fromthe roofs and recycled greywater fromthe bathrooms. The wastewatertreatment comprises a septic tankfollowed by a constructed wetland,which treats the wastewater on site for

infiltration into the ground or, at a laterstage, possibly irrigation. Thus an example of a comprehensivelyecological housing estate was created,combining local traditions and modernsolutions and making use of a range of

Water systemThe potable water supply comes fromthe communal water mains. Due to thehigh location of the house the water isdistributed with a booster pump.

Potable water supply is supplementedby a rainwater harvesting systemcollecting water from 580 m of roofsurface with a total storage volume of 42m. The rainwater is used for laundry, afire fighting reserve, landscaping andirrigation of a wine yard. For laundrytwo common highly efficient washingmachines are provided, where the wateris externally heated from the centralheating system through a heat transferstation for each washing machine. Thefire fighting reserve was necessary as

the apartment buildings are located atthe end of a branch of the water mains,which is not able to supply a sufficient flowfor fire fighting. The overflow of thetanks fills a pond where it is infiltratedinto the ground.Additionally greywater from thebathrooms is collected separately andtreated for reuse in a PONTOS Aquacycle1500, a sequencing batch reactor (SBR)with a capacity of 1000 l/d. It comprisesa two step biological treatment withbacteria growing on a fixed bed of foamcubes, a UV-lamp for disinfection of thetreated greywater before storage, and a

Figure 2: PONTOS Aquacycle 1500,SBR greywater treatment

The blackwater and excess greywaterare treated in a train comprising a 3-

chamber septic tank of 7,5 m, a verticalsubsurface flow constructed wetland anda surface infiltration area. Theconstructed wetland has a length of 26,6,a width of 4,7 and a depth of 1,1 m. It isfed in batches from a feeding chamberlocated downstream of the septic tankand comprising a special pipe valveacting as a float and intermittent outletdevice. No pumps or electronic devicesare needed, which leads to a robustsystem and s imple operat ion and

maintenance. The treatment is designedfor 25 population equivalents. This is theplanned final population of the complexbut was not reached during themonitoring period. The outlet of the

Table 1: Austrian effluent standardsfor small wastewater treatmentplants (less than 50 people

Parameter Limit

BSB5 (mg O2/l) 25

CSB (mg O2/l) 90

TOC (mg /l) 30

NH4-N (mg/l) 1 10


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Greywater treatment in apartment building- Austria

Austria so far has no specificregulations concerning theimplementation of greywater systemsor quality criteria for greywater. There arehowever guidelines of professionalbodies, which give some indications

concerning the implementation, e.g.supply pipes and taps have to be clearlymarked as supplying non-potable water.As for greywater quality, depending onthe intended use, guidelines for specifictypes of water uses, e.g. for irrigationwater, for bathing water, can serve as arule for a minimum quality of thetreated wastewater. Guidelines for theuse of excreta and greywater inagriculture exist from the WHO (2006)but are not yet applied in Austria.

Directive 2006/7/EC from the EuropeanUnion concerning the management ofbathing water quality is often referred tofor the quality requirements of greywaterused for domestic purposes. The bathingwater directive providesquality criteria

for prolonged full-body watercontact.In the present case the treatedgreywater is used for toilet flushing. Itmust not be assumed that toilet

flushing leads to prolonged full-bodywater contact. It hardly leads to anywater contact. Thus the requirements ofDirective 2006/7/EC may not apply.Instead of protection of users fromchemical or microbial hazards, the mostimportant issues to take intoconsideration are technical durability ofthe greywater supply system, i.e. nounacceptable deposits in pipes, andsensorial aspects of the water and thetoilet, e.g. turbidity, odour, colour of the

water and possible deposits in the toilet

but the remoteness of the buildingsuggests the cost would have beencomparable. The rainwater harvestingsystem, which is comprising aninfiltration pond, is also part of thedrainage scheme, thus serving a third

purpose besides providing extra waterand storing the fire fighting reserve.The costs for the standard plumbing arenot available unfortunately. Therefore nocomparison of the costs for overallplumbing to the additional greywater

Table 2: Investment cost of variouscomponents of the water system

Cost Information Cost ba20

Rainwater harvesting system (tank,

plumbing, pump) Greywater heat exchanger

Greywater recycling system (SBR,

plumbing) Constructed wetland for

black water treatment

13.00

Protot

e

In the present case the constructedwetland for the treatment of black waterwas built applying the standard Austriandimensioning rule of 5 m per person,without taking into consideration thereduced hydraulic and carbon load due tothe greywater scheme. If the reducedhydraulic load were taken as the keydimensioning parameter the constructedwetland could have been built with 3 m

ResultsOne target of the monitoring was todetermine whether and to which extendwater saving measures and greywatersystems would contribute to watersaving. A normal person in Austria uses135 litres of potable water per day.

CostThe following system costs are real costsof the implementation. The greywatertreatment and the related plumbingadded up to just below 11.000 Euro. Thewastewater collection and treatmentunder the present configuration wasbuilt for 20.500 Euro (Table 2).The costs of the rainwater harvestingare equivalent to those of the greywatersystem, even though there is no

treatment included. However thereservoirs comprise the fire fightingvolume A detailed assessment of the

55 l

41%30 l

22%

19 l 3114% 23%

Kitchen, other

Bath

Toilet flushing

Laundry, outdoors

Figure 3: Average Austrian domestici i d d f


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Greywater treatment in apartment building- AustriaGreywater treatment in apartment

34 l

32%

Kitchen, othe

Bath

Toilet flushing

Laundry, out

36 l 24

34% 22%

13 l

12%

Figure 5: Water consumption at theapartment house Pllau 18 per capitaand day, for the same categories as in

Fi ure 4: Water flows at

An inhabitant at Pllau 18 uses 107 litresof water per day. However 24 l of theseare greywater and 13 are rainwater, sothat only 70 l are potable water from themains. That is almost down to half fromthe average figure or a yearly saving ofabout 24.000 litres for every person. The respective consumptions in thecategory bathroom are 55 and 34 l/(c.d). This reduction by almost 40 % isprobably due both to water saver fittingsand a water conscious behaviour of theinhabitants. While the reduction also hasan impact on the available volume ofgreywater, in the present case this hasno consequences, as the volume ofshortage under the givencircumstances. If this were notthe case, e.g. due to further

data and will have to be investigated in afurther monitoring phase.The amount of wastewater leaving thebuilding is also down to 76 litres per capitaand day, from the average 120, whichcorresponds to a 37 % reduction.

Quality data for the raw greywater aregiven in Table 3. With a COD of justabove 70 the raw greywater is rather lesspolluted than literature states for

greywater from shower and bath(Eriksson et al., 2002). The COD/BOD5ratio of around 1.25 suggests the

Table 3: Raw greywater quality(Sample size =8; n.d. = not

been possible to add thelaundry runoff to the greywater.

Average Median Standard

Max Min

COD (mg O2/l) 72.4 75.0 34.4 118.0 10.4

BOD5 (mg O2/l) 58.3 53.5 32.5 105.0 17.0

NH4-N (mg/l) 2.4 1.3 2.8 6.9


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Greywater treatment in apartment building- Austria

elimination of carbon as shown in Table4.The nutrient content is particularly lowin this greywater. This may not alwaysbe the case, e.g. if there are babies or ifthe households use any detergent with

AcknowledgementsThis work has been funded by the AustrianFederal Ministry of Agriculture, Forestry,Environment and Water Management(BMLFUW) within the project SustainableSanitation Practical Application

The already low concentration ofnitrogen is further reduced from 10 to 3mg/l in average. Almost all ammonium isdenitrified or at least oxidised. Thetreated service water looks clean,colourless and has no particular odour.This SBR greywater treatment leads towater, which is well suited for purposesbut direct consumption, e.g. toiletflushing, in the household. The water andwastewater savings are substantial and

could help reduce the pressure on waterresources especially in water scarceregions. In future implementations ofsuch systems the cost of the greywaterscheme could be partly offset by thecorresponding savings made on thewastewater treatment. Any savings goautomatically to the developer in the caseof decentralised wastewater schemesimplemented by the developer himself. Inother cases this may not be achievable. Ifwater saving measures or greywatersystems are implemented upstream of

centralised sewerage and wastewatertreatment schemes appropriate tariffs orsubsidies will be needed to transfer atleast part of the overall economicadvantage to the developer.The investment costs are higher for themore complex scheme, than if a watermains connexion and a constructedwetland for wastewater treatment wereimplemented. However, in future suchsystems a more detailed knowledge ofthe wastewater produced will allow toreduce the size of the wastewater

treatment and thus reduce the costaccordingly, thus reducing the gapbetween the two schemes while stillmaintaining the level of sustainability andautonomy.Further investigations have to be madeconcerning the possible size reductionof constructed wetlands, or anywastewater treatment for that matter, incase of a greywater scheme treating partof the wastewater flow. For thispurpose more data are neededconcerning the hydraulic and organicload reduction at the inlet to the

References:AEVkA (1996): 1.

Abwasseremissionsverordnung frkommunales Abwasser (Austrian regulation foremissions from domestic wastewater).BGBl.210/1 996, Vienna, Austria [in German].

BMLFUW (2008): Wasser in sterreich / Basisinfos /Trinkwasser und Wasserversorgunghttp://wasser.lebensministerium.at/article/articleview/6032 3/1/14151/ (date of visit 25 June 2009) [ inGerman]

Eriksson, E., Auffarth, K., Henze, M.,Ledin, A. (2002):

Characteristics of grey wastewater. Urban Water4,85104

EC (2006): DIRECTIVE 2006/7/EC of the EuropeanParliament and of the COUNCIL of 15 February2006 Concerning the Management of BathingWater Quali ty and Repealing Directive76/160/EEC, Official Journal of the European

Name: Martin Regelsberger,Barbara Regelsberger,Christian Platzer

Organisation: Institute forsustainabletechnologies (AEE INTEC)
http://wasser.lebensministerium.at/article/articleview/6032http://wasser.lebensministerium.at/article/articleview/6032mailto:[email protected]://wasser.lebensministerium.at/article/articleview/6032http://wasser.lebensministerium.at/article/articleview/6032mailto:[email protected]


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Combined greywater treatment using amembrane bioreactor

Author: M. Sellner

Abstract The daily fresh water consumption can easily be reduced by using greywater fromshowers, bath tubes and wash basins, when substituting drinking water e.g. for toiletflushing, garden irrigation, cleaning purposes or industrial cooling- processes. The ecologicaland economic advantages of the GEP- Watermanager open up new possibilities of anintelligent water management. It combines a greywaterrecycling- plant with rainwatermanagement, drinking water management, a booster station and a remote controlmodule. Based on a modular construction concept the GEP- Watermanageris operated asa membrane bioreactor with submerged ultra filtration membranes for precious processwater. The attained output values after the recycling process are substantially below the

strict limits set by the EU bathing water regulation. The little footprint and optimisedenergy consumption of the GEP- Watermanager accompanied by high filtrationperformance offers new interesting alternatives for in- building solutions for a

The GEP- Watermanager

Since 1992 the German companyGEP Umweltechnik GmbH develops anddistributes solutions for an optimisedwater management. The first satisfyingsuccess in developing a secure in housegreywater plant, based on a membranebioreactor, took place in 2002. This was

recycling withIn the meantime the process ofimprovement and development moved

(BMT

GEP is able to offer fully automated,remotemonitored and high efficient greywaterplants forin- and outdoor installations. The GEP-Watermanageris designed as a modularconstruction and allows buildingcontractors and engineers a wide scopeof design possibilities. The classicallayouts of greywater plants by GEP areshown in Table1 in association with their

Table1: GEP- Watermanager- main

specific parameters


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Combined greywater treatment using a membrane bioreactor

Backflu

Membrane potable

Greywat Permeat/Efflu

pre-treatedgreywater

Overflow

Overflow

Processwater

TaTa Aeration Rainwat

er

Figure 1: Principel flow chart of the GEP-

Figure 2: The GEP- TridentMAX, ascreen with an mesh size of 0.35 mm

The principle flow chart of GEP-Watermanager is shown in Figure1.First of all the separately collectedgreywater from showers, bathtubs andwash basins pass through a screen with amesh size of 0.35 mm. The solids will be

removed and automatically flushed intothe sewer (Figure2). The pre-treatedgreywater flows into the first greywatertank, where bacteria with the help ofartificially supplied oxygen begin todegrade the organic substancescontained in the greywater.

degradation. The BMT- control panelmonitors and calculates permanently theoptimal hydraulic retention time for highbiological removal performance toachieve a long storable and odourlessprocess water.

Due to the low organic loading rates ingreywater (0,1 kg COD/kg/d) (Paris andSchlapp, 2009) and the high solidretention time in the BMT -Bioreactor the growing rate of biomassis limited too (MLSS 1- 5 mg/ l)(Sellner, 2009). As a consequencethe growing rate of biomass is low andthe period of removing sludge in thetanks is once in a year or even longer.After the biological treatment the heartof the GEP- Watemanager, thesubmerged ultra- filtration starts its

work in the BMT-Bioreactor.The European patentedMicro Clear-filterrepresents a true physical barrier whichblocks allgermsand suspended matters (Figure 3).

Theminute pores of only 50 nm exceedthe requirements of the EU bathingwater guideline 2006/7/EG (2006) andeven the DIN 19650 (1999) class 2requirements for irrigation water. The optimised aeration (withcontinuously-rising, fine air bubblesspaced at intervals) ensures a permanentself- cleaning effect on the filter plates


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Figure 3: Particle size and filtration spectrum for

The process water will be stored in aprocess water tank until its delivery by abooster- system to its consumers. In caseof a lack of process water the requestedamount of water will be automaticallysubstituted by drinking wateraccording to DIN EN 1717 (2001).

The control of the GEP- Waterman ger

provides user friendly completelyautomated and remotely operatedmaintenance of a high technologygreywater treatment p lant. It ispossible to observe, to evaluate and tocontrol the GEP- Watermanager entirelyfrom the office or control centre. Hencethe best moment to change the filtercan be detected which economizes real

thoroughly cleaned. This permits to havea lifetime of up to 10 years per filter.

The result of this unique and safeprocess is a nutrient-poor, odourless,purified process water for furtherapplications. In Table 2 the results of anine week measurement in a studentdormitory are shown. In addition to thatthe process water qualities guaranteedby GEP, according to the information

sheet (FBR-Hinweisblatt H201, 2005), willbe mentioned there as well.

Figure 4: Operation method offiltration with the MicroClear

The GEP-Watermanager is quite morethan an ordinary greywater treatmentplant. At the same time it can be operatedwithout any problems with drinking water,greywater, process water and rainwater.In the opinion of GEP the bonding ofgreywater- recycling and rainwaterharvesting is current ly the mostsus tainabl e manner of decentralizedwater management.For this reason the GEP-Watermanageriscomposed of systems by greywatermanagement,rainwater management , drinkingwa ter management, booster station and

remote control module. The convincingmodular concept and thef lexibi li ty in tank versions allow


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Table 2: Results of a nine week measurement in a studentdormitory with 174 residents (Sellner and Schildhorn, 2009)compared with the recommended values of process water (FBR-Hinweisblatt H201, 2005).

References

2006/7/EG (2006): EU- Directive concerning themanagement of bathing water quality. EuropeanUnion, 2006. Official Journal L64/37 to L64/51 on4.3.2006, Brussels, Belgium.

DIN EN 1717 (2001): Schutz des Trinkwassers vorVerunreinigungen in Trinkwasserinstallationen

undallgemeine Anforderungen anSicherheitseinrichtungen zur

Verhtung von Trinkwasserverunreinigungendurch

Rckflieen.Deutsches Institut fr Normung e.V.,Beuth

Verlag

5.copy of ecosan-grey water

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