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technical data sheets for ecosan components ecosan program - Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ) GmbH

03 Composting SOLID GREY RAIN BIOWASTE FAECES WATER WATER

B.4 Composting toilets with mixing devices COLLECTION • Waterless systems

• Receive mainly faeces, but treatment of urine and solid biowaste is possible as well TREATMENT • Dry organic bulking material should be added

• Produce a valuable soil conditioner with low pathogen UTILIZATION content • Suitable for both industrial and developing countries

B.4 Automated composting toilets

A General Description The Biolet system B Detailed information on differ- ent types of “Composting Toi- lets ” B.1 Single-vault composting toilets B.2 Multiple-vault composting toilets B.3 Movable bucket / bin composting toilets B.4 Composting toilets with mixing devices C Manufacturers and commercially available composting toilets Figure 1: The Biolet (source: www.biolet.com)

B.4.1 Functional Principles thermostats to guarantee a constant operation, no further sawdust or other Several composting toilet manufacturers temperature above 50 to 60°C produce materials need to be added. The condi- have developed improved designs to pathogen free that can directly tion of the sawdust should be checked optimize user comfort and composting be used without further precaution regularly to make sure that it does not process. measures. dry up or gets too wet. The compost has to be withdrawn semi-annually or annu- The basic principle of those toilets is Ventilation is always necessary to pre- ally, depending on usage frequency of that the composting vaults are equipped vent odours and to improve aeration. the toilet system. The system is then with a device that allows mixing of the System sizes vary from small individual emptied completely and a new load of content. The composting vault is usually systems that can be installed within the sawdust is being filled into the chamber pre-filled with a large amount of saw- to large systems for public toi- for starting a new batch. dust or a similar organic material. Fresh lets. Even very large systems that re- faeces are mixed thoroughly into the Continuous systems are also being pre- ceive organic from industries are filled with organic absorbent (sawdust or sawdust matrix, good aeration and in- being produced. tensive contact with the micro organ- other) before first use. However, small isms in the matrix allow for very fast Systems may use batch or continuous amounts of organic absorbent need to composting of the faeces. processing. be added regularly during operation. The system allows extracting a small The mixing device can be mechanically B.4.2 Handling and Maintenance amount of mature compost, while fresh driven and activated by hand or foot af- material remains into the composting ter each use, or electrically driven and Handling and maintenance require- ments depend on whether batch or con- chamber for processing. Small amounts activated by pushing a button or auto- of compost need to be emptied in fre- tinuous systems are being used. matically by sensors. quent intervals, e.g. once a month. Systems can also receive urine; how- In batch systems composting vaults are filled before use with sawdust or similar The resulting compost can be used di- ever a larger volume of absorbing mate- rectly as soil conditioner or undergo fur- rial and heating is then needed for organic and absorbing materials. During evaporating excess liquids. Urine diver- sion allows building smaller systems. Some systems are equipped with heat- ing systems to evaporate urine and/or to maintain optimum conditions for com- posting and pathogen destruction. Sys- tems that have heating controlled by

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technical data sheets for ecosan components ecosan program - Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ) GmbH

The BioLux system Photos from left to right: • System sketch • Mixing device inside the reactor with sawdust matrix • Mixing device without sawdust matrix • above composting chamber • Toilet seat and buttons to activate mixing • Handdriven mixing device • Verious models for use in nursing care • Large composting unit for industrial use • building, toilet and composting chamber

Figure 2: The Bio-Lux composting toilet (source: GTZ) ther processing. tems are small units that can be simply heating system. The BioLux is being installed in of individual produced in a wide range of sizes. Units Power supply is needed in most sys- houses. They use continuous process- have been installed for example in zoos, tems for heating, mixing device and ing and come with mechanical or elec- mountain areas (Mt Fuji), skiing ventilation. trical mixing devices, and both with or grounds, private houses or public build- B.4.3 Extent of Application without heating systems. Urine is di- ings in Japan, or are being used as mo- verted and collected separately. bile toilets for construction sites. BioLux Scandinavian designs such as the systems are also available for areas Biolan Naturum or the Biolet have been The Japanese manufacturer Seiwa without power supply; power is then Denko Co has developed the BioLux produced in large numbers and are generated using wind mills or solar commercialised in Europe, North Amer- system. This system processes both panels or a mechanical system with bi- ica, Australia and Japan. Those sys- urine and faeces in batch mode; it usu- cycle pedals is used for mixing. ally has an electric mixing device and

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technical data sheets for ecosan components ecosan program - Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ) GmbH

The Biolan Naturum composting toilet Function

Evacuation of mature compost System sketch

Figure 3: The Biolan Naturum composting toilet (source: www.natrurum.fi)

B.4.4 Design Information B.4.5 Economic Data Systems that evaporate urine have very high electricity consumption. Urine di- Small systems for installation in individ- Prices for the Naturum and Biolet Sys- version allows avoiding this negative ual houses usually come in standard- tes range from 1.000 to 1.500 Euros. aspect. ised sizes designed for an average The prices for the Japanese BioLux number of users. Emptying frequency range from 3.000 to 35.000 euro, de- Costs and benefits depends on the number of actual users. pending on the size. Composting toilets with mixing devices Mature compost typically has to be ex- have similar costs as other types of tracted once a month. Those systems B.4.6 Strengths and weaknesses manufactured composting toilets. Cost are very compact and can be installed Health impact for electricity is higher, required time for in any usual bathroom. Connections for maintenance is lower than of the other ventilation and are re- As the described systems optimize types of composting toilets. Costs for quired. composting process by mixing and heating devices, a perfectly safe prod- post-treatment or other safety measure Large systems such as the larger ver- uct is usually obtained. Systems without before reuse of compost are lower than sions of the Japanese BioLux are usu- permanent heating may require further in many other types of composting toi- ally detached from the toilet and located treatment of compost or other safety lets, as the hygienic quality is generally beneath bathrooms or toilet cabins. A measure for safe reuse. better. volume of 1 m³ of sawdust is required Socio-cultural suitability for 150 to 200 users per day. Environmental impact Composting toilets with mixing devices BioLux systems that process urine to- Applying the system reduces signifi- reduce requirement of manual mainte- gether with faeces require much more cantly the introduction of pathogens into nance, which makes them more com- energy for evaporation of excess liquid the water bodies due to the elimination fortable to users than most other types than the Scandinavian systems with of discharge of faecal material into the of composting toilets. User comfort is as urine diversion that use heating only for environment. It also helps in nutrient re- good as in any other modern toilet. The maintaining optimal temperature of the cycling since the resulting compost can available products have consequently compost. be used as fertilizer. The toilet requires no flushing water. proven to be very popular.

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technical data sheets for ecosan components ecosan program - Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ) GmbH

Technical suitability Treatment System (OWDTS). Unpub- lished paper. The systems optimize the composting process and minimize maintenance and Nakagawa, N., Otaki, M., and Ishizaki, user involvement. They are reliable and K. Technical trends in low environ- can be used many different situations. mental load type . www.watermaga- However, application is so far limited to zine.com/secure/jc/Japan.pdf industrialised countries due to their rela- tively high prize and because the sys- Nakata, S., Lopez Zavala, M. A., tems cannot be easily reproduced lo- Funamizu, N., Otaki, M., and Takakuwa, cally. T., 2003, Temperature Effect on Pathogens decline in the Bio-toilet B.4.7 Manufacturer System, Presented at the 1 st A list of manufacturers of composting International Dry Toilet Conference in toilet systems is given in part C. Tampere. B.4.8 Good practice examples Website of Biolan Naturum: http://www.naturum.fi Asahiyama Zoo located in the northern part of Japan caters for thousands of Website of Biolet USA visitors every month. Since 1997, a total http://www.biolet.com/ of 12 BioLux units have been installed. and Biolet Germany: Almost all reactors treat both and http://www.humustoiletten.de/2Funkt2.p urine together and few treat only urine. df#search=%22biolet%22 Survey results showed that the bio-toilet system have had great acceptability not just with the staff of the zoo but espe- cially with the users. In relation to this good result, the man- agement is planning to use bio-toilet to treat animal as well. Address: Asahiyama Zoo, Kuranuma, Higashi Asahikawa-cho, Asahikawa City, Japan See also project data sheet at http://www.gtz.de/en/themen/umwelt- infrastruktur/wasser/9399.htm . B.4.9 References Bio-lux: Environmentally friendly Eco- bio-toilet. http://www.seiwa- denko.co.jp/biolux/top.html Funamizu, N. Development of Sustain- able Sytem and its Imple-  2006, GTZ mentation to Asian Countries: an inter- disciplinary research project in Japan technical data sheets for ecosan Science and Technology Agency. components www.xauat.edu.cn/FUWWS- authors: GTZ ecosan team (Christine XIAN2005/keynote-pdf/Naoyuki.pdf Werner, Aileen Huelgas, Florian Klingel, Patrick Bracken) Funamizu, N. Onsite Differentiable Treatment System: the System for Deutsche Gesellschaft für Technische achieving in the Sanita- Zusammenarbeit (GTZ) GmbH tion System. ecosan program www.scj.go.jp/en/sca/pdf/5thposter8.pdf Dag-Hammarskjöld-Weg 1-5 65760 Eschborn, Germany Lopez Zavala, M. A., Funamizu, N. And T +49 6196 79-4220 Takakuwa, T., 2002, Characterization of F +49 6196 79-7458 Feces for Describing the aerobic Bio- E [email protected] degradation of Feces, J. Environ. Syst. I www.gtz.de/ecosan And Eng., JSCE, No 720/VII-25, 95-105 Lopez Zavala, M. A., Funamizu, N. and Takakuwa, T., 2005. Bio-toilet: A key unit element for achieving sustainability in the Onsite Wastewater Differentiable

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