ecosan - recycling beatsdisposal

on behalf of:

Bundesministerium fürwirtschaftliche Zusammenarbeitund Entwicklung

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Conventional forms of wastewatermanagement and sanitation arecoming under increasing criticismfor ecological and economic rea-sons. The reason for this is notonly the rising cost of building, op-erating and maintaining such sys-tems, but also the fact that theymisuse drinking water as a trans-port vehicle and contribute towardthe contamination of water cycleswith sewage. This causes healthhazards and damage to the envi-ronment. Even individual disposalsystems, such as latrines andcesspits, make poor alternativesin densely populated areas, be-cause they lead to the contamina-tion of groundwater.

Despite extensive internationalefforts, some 2,2 million people,most of them children, die eachyear of illnesses caused by con-taminated drinking water andinadequate sanitation and hygiene.

Moreover, conventional waste-water disposal systems causedirect impairment of soil fertility,because they usually prevent thevaluable nutrients and trace ele-ments contained in humanexcrements from being rechan-neled into agriculture. And evenwhen sewage sludge is put to agri-cultural use, only a small fractionof the nutrients are actually rein-troduced into the bioactive topsoil. Most of the nutrients areeither destroyed (e.g., by the nitrogen elimination process) or findtheir way into the water regime, where they pollute the environ-ment. Frequently, the use of sewage sludge from centralizedwastewater management systems must also be restricted due tothe high concentration of heavy metals and other harmfulsubstances, often as a result of intermixing household sewage

with industrial wastewater and surface runoff from contaminatedstreets.

In fact, our conventional wastewater systems are basically linearend-of-pipe systems, in which drinking water is misused to trans-port waste into the water cycle, resulting in environmental dam-age and health hazards.

The problem with conventional sanitation systems

Shortcomings of conventional sanitation systems

source: gtz

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“end of the pipe”photo: GTZ

water closetphoto: Annette Schlemm

open sewer in Chinaphoto: GTZ

· Unsatisfactory purification or uncontrolled discharge of

more than 90 % of wastewater worldwide

· Extreme environmental and health problems due to water

pollution caused by the introduction of organics, nutrients,

pathogens, pharmaceutical residues, hormones and

hazardous substances

· Consumption of precious water for sewage transport

purposes (water-carriage waste disposal systems)

· High investment, energy, operating and maintenance costs

· Frequent subsidization of prosperous areas and neglect of

poor settlements

· Preferential use of centralized, combined systems of organ-

ized disposal, resulting in contamination with hazardous

substances from commercial / industrial wastewater

· Loss of valuable nutrients and trace elements contained in

human excrements, with resultant loss of soil fertility and

agricultural productivity

· Increasing dependence on chemical fertilizers

· Linear end-of-pipe technology

Global situation

· 1,200 million people around the world have no access to

safe drinking water.

· Nearly 2,500 million people have inadequate sanitation

and/or no means of wastewater disposal.

· More than 90 % of all the world's wastewater is either not

being satisfactorily purified or is being discharged in an

uncontrolled manner.

· Some 80 % of all illnesses and 25 % of all deaths in emerg-

ing countries are attributable to contaminated water.

(source: WHO)

An alternative approach thatavoids the disadvantages of con-ventional wastewater systems isecological sanitation, 'ecosan' forshort. This considers materialflows as part of ecologically andeconomically sustainable waste-water management systems tai-lored to local needs. It does not fa-vor a specific technology, butconstitutes a new philosophy fortreating substances that have sofar been seen merely as waste-water and water-carried waste fitonly for disposal. Systems basedon this approach are used for thesystematic closure of local materi-al-flow cycles and operate alongthe same lines as recycling sys-tems already in common use forsolid waste.

Closed-loop wastewater manage-ment and sanitation helps restorea remarkable natural balancebetween the quantity of nutrientsexcreted by one person a year andthe quantity it takes to produce hisfood. Ideally, ecosan systems en-able the almost complete recoveryof all nutrients and trace elementsfrom household wastewater andtheir reuse in agriculture. They helppreserve soil fertility and safe-guard long-term food security. Thetechnology employed can be sim-ple low-tech arrangements orsophisticated high-tech systems.This ranges from composting or urine-separating dry toilets towater-saving vacuum sewage systems with separate collectionand subsequent treatment of urine, faeces and greywater,through to membrane technology for material separation and hy-gienization. Of key importance are also innovative logistics to re-turn nutrients to farmland, marketing strategies for the recoverednutrients and directions for their safe application in agriculture.

New ecosan schemes may also entail setting up service enter-prises to construct and operate the installations as well as tocollect, treat and market recyclates. Such measures haveincome-generation benefits for the local population.

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Advantages of ecological sanitation

Advantages of ecological sanitation

source: gtz

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ecosan toilet in Mexicophoto: Steven Esrey, Unicef

field irrigation

fertilization with slurry injectorphoto: Veenhuis Machines, NL

substances urine(yellowwater)

treatment

utilisation

hygienisation bystorage or

drying

liquid or dryfertiliser

faeces(brownwater)

anaerobicdigestion,

drying,composting,

biogas,soll

improvement

greywater(showers, washing,

etc.)

constructed

wetlands, gardening,

wastewater ponds, biol.

treatment, membrane-

technology

irrigation,groundwaterrecharge ordirect reuse

rainwater

filtration,biol. treatment

water supply,groundwater

recharge

water

agriculture

hygiene

protection of water resourcesthrough reduced consumption

and less contamination

higher agricultural yieldsthrough the re-utilisation

of nutrients

minimisation ofwater-based infections

ecological sanitation

· promotes recycling (safe, hygienic recovery and use ofnutrients, trace elements, water and energy)

· conserves resources (lower water consumption, substitu-tion of chemical fertilizers, minimal water pollution)

· improves health by minimizing the introduction ofpathogens from human excrement into the water cycle

· gives preference to modular, decentralized, partial-flow(split-stream) systems for more appropriate, cost-effectivesolutions

· helps preserve soil fertility

· improves agricultural productivity and, hence, contributestoward food security

· promotes a holistic, interdisciplinary approach (watersupply and sanitation management, conservation of re-sources, environmental protection, urban planning, agricul-ture, irrigation, food security, small-business promotion,health, household energy)

· recycling beats disposal

ecosan – triple win

separation of substances

source: otterwasser gmbh

source: gtz

ecosan principles and examples of technologies

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vacuum station / photo: Roediger GmbH

preparing for rainwater harvesting / photo: GTZ

biogas plant mixing and hygienization unit / photo: GTZ

“No mix” separating WC / photo: Roediger GmbH

fertilization with hose applicator / photo: Veenhuis Machines, NL

Terra Nova composting toilet / photo: Berger Biotechnik

biogas dome under construction / photo: GTZ

vacuum toilet system / photo: Roediger GmbH

soilization of sewage sludge / photo: AKUT GmbH

irrigation by hand / photo: GTZ

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composition of household wastewater

agricultural utilisation of nutrients from domestic sewage

hygiene quality standards for treated feaces

characteristics of substances

source: gtzsource: TUHH

source: WHO

source: gtz

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On-plot ecosan systems for the treat-ment of faeces, urine and greywater inMali

Koulikoro, Mali, has a central potable water supply system dat-ing from the 1970s, but as yet no sewage system. In an arid sub-Saharan country like Mali, where financial and water resourcesare scarce, a water-carrier sewage system resembling those usedin Europe would be inappropriate and too expensive. Mali is al-so faced with the steadily worsening problem of soil degradation,up to and including desertification, chiefly as a result of agricul-tural overuse and insufficient return of nutrients.

An affordable means of proper wastewater disposal is needed.GTZ is therefore developing an on-plot household ecosan systemin which faeces, urine and greywater are separately collected andtreated. This offers major advantages over conventional latrine-based systems, as it enables the hygienic recovery of soil-amending substances from faeces and of nutrients from urineand purified greywater. The ecosan system is also in harmonywith local traditions.

In 2002, the National Sewage and Solid Waste Department at theMalian Ministry of the Environment incorporated the greywatergardens and separating toilets developed by the ecosan initiativeinto its program. Together with GTZ, the department is now ex-amining their suitability for widespread introduction. Ultimately,however, the success of greywater gardens depends solely onthe degree to which they are accepted by women for growingvegetables, bananas and papayas.

Municipal ecosan concepts in a Chinese suburb

Located in one ofBeijing's three riverbasins, Yang Songcovers a little morethan three square kilo-meters and is home tosome 21,000 people. With its intensive live-stock farming andgrain and vegetableproduction, the regionis a major source offood for the city ofBeijing. The communitycurrently produces roughly 15 tonnes of solid waste each day.Less than 10 % of the town's wastewater is treated prior to beingdischarged into the rivers or groundwater.

Within the scope of a localecosan project, the communityis to be provided with a mod-ern, material-separating dis-posal and recycling conceptfor wastewater and organicwastes that is in line with theprinciples of closed-loopwastewater management andsanitation. GTZ, Chinese andGerman scientists and com-

panies are working together to analyze and compare differentsanitation, wastewater treatment and recycling options in variousharmonized systems. The cost-effective recovery of usefulmaterials and energy is the main objective.

There are also plans to use water-saving vacuum technology andurine separation systems. Organic waste from kitchens and mar-kets will be collected, shredded and, finally, fermented in a bio-reactor system. The resultant fertilizer and hygienized urine willbe suitable for use in growing flowers and vegetables. Greywaterwill be used for watering public parks and gardens.

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ecosan concepts in operation

separation toilet in Chinaphoto: Steven Esrey, Unicef

ecosan toilet with greywater gardenphoto: GTZ

“No mix” separating WCphoto: Roediger GmbH

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model of a Chinese ecosan toiletphoto: GTZ

constructed wetland in Germanyphoto: Otterwasser GmbH

ecosan separation toilet with greywater treatment

photo: GTZ

ecosan as an element of sustainableregional resource management inBotswana

In many countries of Africa, including Botswana, conventionalforms of wastewater disposal have drawbacks for the generalpopulation. Most households located outside of the major urbancenters are not connected to any existing waste managementand sanitation system. Droughts and inadequate water resourcesmake an already unsatisfactory situation even worse.

Over the next five years, a project devoted to sustainable regionalresource management will be cooperating with local authorities,the International Union for the Conservation of Nature (IUCN) andthe German Development Service (DED) in developing, testingand demonstrating sustainable noncentralized wastewater man-agement and sanitation systems and methods. Initially, privatehouseholds in the districts of Ghanzi, Gaborone and Serowe areto be tied into the research activities. Later, the approach will beextended to the municipal level.

One of the aims of this GTZ-project is to recover nutrients andtrace elements from domestic wastewater, faeces and urine foruse in agriculture. This not only contributes toward long-termfood security, but also provides the people with an opportunity toearn extra money.

Furrow irrigation in Africaphoto: GTZ

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ecosan concepts in operation

Soilization of sewage sludge andclosed-loop sanitation on Nile cruisers in Egypt

In many countries, the use of sewage sludge in agriculture isthwarted either by the complexity of the processing technologyor by the poor quality of the sludge, which awakens little interestamong farmers for use as a soil conditioner. In Egypt, GTZ hastherefore entered into cooperation with IPP-Consult in support ofa project devoted to the scientific study of sewage-sludgeupgrading, or soilization, by means of seeding sludge polderswith grass or common reed.

The results are promising: · process technology is easy to manage and economical;

· structural, aesthetic and hygienic attributes of the soilizedsludge are superior to those of dried sludge;

· soilized products find more acceptance and market potentialis improved.

Another ecosan activity will be to launch a pilot project on theclosed-loop management of municipal wastewater in Aswan. Akey element will be the environmentally correct disposal of waste-water from Nile cruisers. At present, such wastewater is still be-ing dumped untreated into the clear, fresh waters of the Niledownstream of the huge Aswan Dam. The ships' existing equip-ment easily enables the separate collection of urine, faeces andgreywater. The material collected in different tanks in the courseof the cruise will be suctioned off by service ships or transfer sta-tions at the cruisers' landing places in Aswan, Edfu and Luxor andthen brought ashore for processing and subsequent agriculturaluse, for example on tree farms.

ecosan research into noncentralized applications in Cuba

Throughout Cuba, and particularly in urban areas, the wastewatermanagement and sanitation systems lack capacity and are inurgent need of rehabilitation. Most notably in periurban areas withconsiderable agricultural activity, the soil, groundwater and wa-tercourses are heavily polluted. As a result, health conditions andodor-nuisance levels are critical in many places. Moreover, manyhouseholds do not have access to electricity. This forces manypeople to use ecologically questionable forms of fuel for theireveryday needs.

To address the situation, a GTZ-supported ecosan researchproject is conducting field tests on various household sanitationsystems and looking for appropriate-technology solutions whichgenerate cooking-energy yields. For example, on several cityfarms in two different project regions, the disposal or utilizationof household sewage and organic waste is being integrated intothe in-house production of fertilizer and cooking energy. In a thirdregion, prefabricated components are being designed and

developed for diverse decentralized disposal systems, and in afourth region, different ecosan systems are being implemented inurban centers. The four regions in question are located in differ-ent parts of the island to ensure the study is representative of theisland’s diverse climatic, structural and social conditions.

Nile cruiser, Egyptphoto: Phoenix Reisen

biogas domephoto: GTZ

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holiday resort in Fiji with greywater and rainwater systemsphoto: David del Porto, USA

growth trial with treated sludgephoto: IPP Consult

sludge drying bedsIPP Consult

Sanitary systems in Ouagadougou, Burkina Faso

The climatic and social conditions in Ouagadougou, the capitalof Burkina Faso, are typical for a country in the sub-Saharan sa-vannah belt: surface water, which represents the city’s majorsource of drinking water, is stored in open reservoirs and there-fore extremely vulnerable to pollution. The limited groundwaterresources are very important, both as a relatively uncontaminat-ed source of water and as a reserve supply in particularly dryyears. The simple pit latrines used by 93% of the population

infiltrate into the groundwater. Once discarded, they contaminatethe receiving water body and contribute to the high levels of wa-ter-related diseases. Thus, conventional sanitary systems havecreated a dilemma between the need for sanitary disposal of hu-man excreta, the protection of water resources, and the increasedagricultural activity needed to meet the rising demand for food.That dilemma can be addressed if human excreta are recognizedas a potentially valuable resource.

The extent to which ecosan sanitation systems can be introducedin Ouagadougou as part of a closed-loop, or material-flow-oriented recycling process is currently being investigated by GTZ.The findings are expected to be on hand by the end of 2002.

ecosan latrinesphoto: GTZ

• Knowledge management and networkingIn cooperation with international and local partners, the ecosan pro-ject collates existing know-how so that experience already on handcan be used and further developed. This knowledge may include thecontents of publications as well as practical know-how from users andexperts on established and new ecosan-specific developments, theproblems encountered, news of successful projects, research findingsand much more.

The ecosan project is promoting the systematic development of a glob-al sector-specific network of persons, institutions and projects. It addresses experts, potential users and decision-makers who arelooking for information, seeking concrete answers to specific ques-tions, in need of decision-making tools or looking for contacts.

The GTZ ecosan project supports this network in many ways:• e-newsletter

Since June 2001, the ecosan-project has been producing a mul-tilingual electronic newsletter (in English, German, Spanish andFrench); it contains news of interesting new developments in eco-logical sanitation, information on and downloading options forcurrent publications, details of upcoming events, contacts andinteresting links, plus a sector forum for communicating with areadership of several thousand. The electronic GTZ ecosannewsletter appears quarterly in all four languages.

View and download previous newsletters athttp://www.gtz.de/ecosan/newsletter.html

Registration: If you wish to subscribe to the ecosan newsletter,please send an e-mail containing only the words "subscribeecosan" to majordomo@mailserv.gtz.de

• ecosan websiteCurrent information on closed-loop wastewater managementand sanitation is available in German and English at: www.gtz.de/ecosan

• Conferences and workshopsOrganization of and participation in international events.(e.g., 2nd International Symposium on Ecological Sanitation ecosan - closing the loop" April 7 -11, 2003, in Lübeck, Germany.For a program and details, go to http://www.gtz.de/ecosan/symposium-2003.html)

• EcosanetCooperation with partners from the EU, China and Africa in thefield of development cooperation and research geared to estab-lishing and promoting a global ecosan network

• National and international working groupsInitiation and coordination of expert working groups as projectthink-tanks to establish basic materials and develop modelecosan concepts

• Design and implementation of pilot projectsThe design and implementation of - mostly urban - research anddemonstration projects is the other main focus of GTZ's ecosan pro-ject. The aim of such pilot projects is to arrive at cost-effective, user-needs-oriented, practicable ecosan solutions which benefit users. In addition to addressing sanitation technology issues, another es-sential component of ecosan pilot projects are the concepts neededfor the safe agricultural and horticultural application of the recoveredproducts. Market analyses and suitable marketing strategies for the re-covered recyclates are also necessary. And cost comparisons withconventional systems are just as important as the development oftraining modules for users, service enterprises and farmers, and healtheducation measures.

Christine Werner

civil engineer, project team leader

tel: +49 (0) 6196 / 79 -1740

e-mail: christine.werner@gtz.de

Heinz-Peter Mang

engineer

tel: +49 (0) 6196 / 79 -1741

e-mail: heinz-peter.mang@gtz.de

Jana Schlick

architect

tel: +49 (0) 6196 / 79 -1765

e-mail: jana.schlick@gtz.de

Susanne Becker

administration secretary

tel: +49 (0) 6196 / 79 -1764

e-mail: susanne.becker@gtz.de

ecosan project services

Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ) GmbHChristine WernerSector Project "ecosan"Postfach 5180D-65726 EschbornGermany

Eschborn, August 2002

ecosan, a supra-regional research and development project fund-ed by the German Federal Ministry for Economic Cooperation andDevelopment (BMZ), was launched in May 2001 by GTZ. The pro-ject aims to promote the global breakthrough of holistic newapproaches to wastewater management and sanitation based onthe systematic closure of local material-flow cycles.

Ideally, ecosan systems enable the almost complete recovery ofall nutrients and trace elements contained in domestic waste-water. Appropriately treated, such raw materials can be returnedto the agricultural process, where they help maintain soil fertilityand ensure long-term food security. At the same time, ecosan sys-tems contribute to the conservation of our water resources and toreducing water-related environmental pollution and health risks.