M3: ecosan Systems and Technology Components

M3: ecosan Systems and Technology Components
DEMO-VERSION: LINKS TO EXTERNAL DOCUMENTS DO NOT WORK! M3: ecosan Systems and Technology Components M 3-1: ecosan Technologies to Close the Nutrient Loop J. Heeb Prof. Dr. Petter Jenssen, Department of Mathematical Sciences and Technology, Norwegian University of Life Sciences Dr. Johannes Heeb, International Ecological Engineering Society & seecon international Dr. Ken Gnanakan, ACTS Bangalore, India Katharina Conradin, seecon gmbh © 2006 seecon International gmbh ACTS Agriculture -Crafts - Trades - Studies

Credits K. Conradin Materials included in this CD-ROM comprise materials from various organisations. The materials complied on this CD are freely available at the internet, following the open-source concept for capacity building and non-profit use, provided proper acknowledgement of the source is made. The publication of these materials on this CD-ROM does not alter any existing copyrights. Material published on this CD for the first time follows the same open-source concept for capacity building and non-profit use, with all rights remaining with the original authors / producing organisations. Therefore the user should please always give credit in citations to the original author, source and copyright holder. We thank all individuals and institutions that have provided information for this CD, especially the German Agency for Technical Cooperation GTZ, Ecosanres, Ecosan Norway, the International Water and Sanitation Centre IRC, the Stockholm Environment Institute SEI, the World Health Organisation WHO, the Hesperian Foundation, the Swedish International Development Cooperation Agency SIDA, the Department of Water and Sanitation in Developing Countries SANDEC of the Swiss Federal Institute of Aquatic Science and Technology, Sanitation by Communities SANIMAS, the Stockholm International Water Institute SIWI, the Water Supply & Sanitation Collaborative Council WSSCC, the World Water Assessment Programme of the UNESCO, the Tear Fund, Wateraid, and all others that have contributed in some way to this curriculum. We apologize in advance if references are missing or incorrect, and welcome feedback if errors are detected. We encourage all feedback on the composition and content of this curriculum. Please direct it either to or seecon K. Conradin

Credits ecosan Curriculum - Credits
K. Conradin ecosan Curriculum - Credits Concept and ecosan expertise: Johannes Heeb, Petter D. Jenssen, Ken Gnanakan Compiling of Information: Katharina Conradin Layout: Katharina Conradin Photo Credits: Mostly Johannes Heeb & Katharina Conradin, otherwise as per credit. Text Credits: As per source indication. Financial support: Swiss Development Cooperation (SDC) How to obtain the curriculum material Free download of PDF tutorials: Order full curriculum CD: € 50 (€ 10 Developing Countries) Release: 1.0, March 2006, 1000 copies Feedback: Feedback regarding improvements, errors, experience of use etc. is welcome. Please notify the above -addresses. Sources Copyright: Copyright of the individual sources lies with the authors or producing organizations. Copying is allowed as long as references are properly acknowledged. seecon

Note & Information on Structure
Note: This Module is mainly adapted from two different sources: WHO (2005): Guidelines for the Safe Use of Wastewater, Greywater and Excreta. Chapter: Health Protection Measures (draft version) and Chapter 4 of the Conceptual Design of decentralised Wastewater Treatment and Material Flow Management, Summer Course 2004 at the University of Hannover: “Sustainable Wastewater Management in Urban Areas” by P.D. Jenssen, J.M Greatorex & W.S. Warner,

Contents Introduction Content Overview
J. Heeb Introduction Content Overview Source Separated Wastewater Collection/Treatment Systems Pit Toilets Pit & VIP Latrines Pour-Flush Latrines Composting Toilets Treatment: On-site/off-site dry composting Treatment: Composting Toilets – Dry Composting Process Further Information on Composting Toilets Dehydration Toilets Treatment: Dehydration Toilets Further Information on Dehydration Toilets Urine Diversion Toilets Single-Flush Urine Diversion Toilets Dual-Flush Urine Diversion Toilets Waterless Urinals Treatment: Urine Storage Further Information on Urine Diversion Toilets

Contents Watersaving Toilets Vacuum Toilets Vacuum Sewer Systems
J. Heeb Watersaving Toilets Vacuum Toilets Vacuum Sewer Systems Vacuum Collection Tanks with Vacuum Pump Vacuum generating and forwarding pumps Vacuum on Demand (VOD) Further Information on Vacuum-Toilets Treatment: Treatment of blackwater fractions and organic waste Treatment: Aerobic Treatment (Liquid Composting) Treatment: Anaerobic Treatment (Biogas Production) Treatment: Drying and Humification Treatment: Further Treatment Methods Vermicomposting Wastewater-Fed Aquaculture Handling and Transport of Excreta and Sludge Logistics of Sustainable Systems in Urban Areas J. Heeb

Introduction Energy Water (drinking water) Nutrient
Filtration (membrane, sand) Fertilizer (N, P, K) Grey-water Black-water Ground-water recharge Excreta contains most of the pathogens as well as the majority of the nutrients in wastewater (see Module 3-2). If excreta is treated separate and not mixed with the greywater several new possibilities for reuse of resources from wastewater arise. In order to collect excreta only, toilets that use no or very little water are the most feasible. Systems where the excreta is treated and handled separate from the greywater are termed source separating systems. Source separating systems either separate in two fractions the excreta (urine and faeces) and the greywater or some in three fractions urine, faeces and greywater (1). Soil amend-ment Organic waste Biologi-cal Treat-ment Recrea-tional water Aerobic treat-ment (composting) Anaerobic treat-ment (biogas) Watering garden Graphic: Alsén & Jenssen (1)

Content Overview Energy Water (drinking water) Nutrient
Filtration (membrane, sand) Fertilizer (N, P, K) Grey-water Black-water Ground-water recharge This module will mainly concentrate on the nutrient and energy loop. First, this module explains suitable methods for collection of the recyclable resources in excreta (faeces and urine). The various options are explained on several slides, including a general system overview, management processes, risks, and maintenance, as well as advantages and possible drawbacks. Further Information is indicated where available. Additionally, you will find links to websites of product suppliers. The technological aspects of closing the water loop is exemplified in Module 3-2. A figure showing the different collection (i.e. toilet) options which facilitate the reuse and thus the closing of the nutrient and energy loop is shown on the next slide. Soil amend-ment Organic waste Biologi-cal Treat-ment Recrea-tional water Aerobic treat-ment (composting) Anaerobic treat-ment (biogas) Watering garden Graphic: Alsén & Jenssen (1)

Source Separated Wastewater Collection/Treatment Systems
P. Jenssen Close the loop: collection systems that facilitate the reuse are needed (first row). Different toilet options: material of different composition: different treatment systems The slides on treatment systems have a slightly coloured background!! In order to be able to close the loop shown on the preceding slide, collection systems that facilitate the reuse are needed (first row). The different toilet options produce material of different composition regarding e.g. water content and hygiene therefore different treatment methods are required. What is inherent to all these systems is that they use as little water as possible, and thus keep the volumes that has to be treated small. As you can see the greywater is separated right from the beginning, and is not incorporated into the treatment processes of excreta. Greywater usually only has a very small grade of pollution and is much easier to sanitize than black- or yellowwater. The second row shows the treatment processes which are applied according to the respective collection systems, in order to make a hygienic product for reuse. Collection options are highlighted in yellow and Treatment/Hygienization systems in orange.

P. Jenssen Close the loop: collection systems that facilitate the reuse are needed (first row). Different toilet options: material of different composition: different treatment systems The slides on treatment systems have a light yellow coloured background!! In order to be able to close the loop shown on the preceding slide, collection systems that facilitate the reuse are needed (first row). The different toilet options produce material of different composition regarding e.g. water content and hygiene therefore different treatment methods are required. What is inherent to all these systems is that they use as little water as possible, and thus keep the volumes that has to be treated small. As you can see the greywater is separated right from the beginning, and is not incorporated into the treatment processes of excreta. Greywater usually only has a very small grade of pollution and is much easier to sanitize than black- or yellowwater. The second row shows the treatment processes which are applied according to the respective collection systems, in order to make a hygienic product for reuse. Collection options are highlighted in yellow and Treatment/Hygienization systems in orange.

Principle difference option 1 and option 2-4 1) Pit toilets: pits or soakaways in natural soils  threat to groundwater resources  designed for disposal of excreta – however, excreta can be reused by excavating the full latrines 2)The collection options 2-4 in general collect all excreta for on- or off-site treatment  protection of local groundwater  possibilities to recigle nutrients Note: greywater is separated at a household level. More details will be provided in M3-2 The toilet options used in the source separating systems range from pit toilets to modern urine diverting and vacuum toilet systems. There is a principle difference between the pit- and pour flush toilets (1) and the other options (2-4) in that the first utilize pits or soakaways in natural soils. These pose a threat to the groundwater quality and subsequently health, especially in areas where water from shallow wells is used. The pit toilets are originally constructed for disposal of excreta and not for reuse. A substantial amount of nutrients, nitrogen especially, is lost through percolation or evaporation. However, since excavating of full pit latrines provides possibilities of recycling phosphorus and organic matter in particular, they are still included in this module on ecosan technologies. The collection options 2-4 in general collect all excreta for on- or off-site treatment and thus provide better protection of the local groundwater and better possibilities for recycling of nutrients. Still, the composting or dry sanitation options (2) loose nitrogen to the air. The urine diverting (3) or low flush vacuum or gravity systems with holding tanks (4) have very little loss of plant nutrients prior to agricultural application when handled properly. The different toilet options and the subsequent excreta treatment and handling options are briefly described below. The preceding graph shows that for the source separating options greywater is separated at the household level. Greywater may be treated on-site or off-site for a cluster of homes of for a section/block in an urban area. Greywater treatment options are described in module M3-2. Source: Adapted from: (29) Source: Adapted from: (29)

Pit Toilets P. Jenssen

Pit Toilets A: Pit latrines:
dry systems (no water for flushing needed. normally dug quite deep  percolate may seep into groundwater B: VIP-latrines (Ventilated Improved Pit Latrine) elevated: greater distance to groundwater ventilation pipe reduces odors “Pit and VIP latrines are so-called ‘dry’ systems that do not require water for flushing. In the pour flush toilets 1 – 3 liters is used to flush the water to the soakaway. The traditional pit latrine (A) is normally dug quite deep and there are several examples of such latrines discharging their percolate directly into the groundwater. The VIP-latrines (B) are improved in two ways compared to the traditional pit latrine (A); Firstly, they are elevated and thus increase the distance to the groundwater and secondly a ventilation pipe reduces odors in the toilet room if properly constructed. The ideal ventilation is down through the toilet and out through the ventilation chimney (see composting toilets below). Whenever pit latrines are used shallow pits (B) are recommended because this increases the distance down to the groundwater.” (29) Source: (29)

Pit & VIP Latrines Generally: The faster the decomposition of excreta, the less health hazards. Decomposition in the pit is more rapid if the material is not to wet or to dry.  adding of bulking agents (straw, hey, woodchips) may be beneficial Unimproved pit latrines: Flies who come into contact with faeces are can transmit diseases:  Fit fly mesh to ventilation pipe  add bulking material to cover faeces + ash as a bulking agent will elevate pH and enhance pathogen die-off Source: Adapted from: (29) “Generally, the faster the decomposition of excreta takes place, the less are the health hazards that arise from it. Decomposition of the excreta in the pit is more rapid if the material is not to wet or to dry. In a well-drained soils moisture drains out. It still may be beneficial to add bulking material as straw, bark or wood chips to the pit to optimize the moisture content. This will also reduce leaching and potential contamination of the groundwater. If unimproved pit latrines are used, an additional health hazard is caused through the presence of flies who are in contact with the faeces. This increases the risk of transmitting diseases. Reducing the ability of flies to transmit pathogenic organisms from faeces to food is an important public health intervention. Fitting fly mesh to the ventilation pipe (VIP) and using a toilet cover can be important measures. Frequent adding of bulking material or ash may also reduce the possibility for flies to come in contact with fresh faecal material. Adding ash will cause a rise the pH and enhance pathogen die-off.” Adapted from: (29)

Pit & VIP Latrines - Risks
Pit latrines: high risk of groundwater contamination Separation distance is very important:  distance should be maximized. Distance depends on The soil texture, The soil structure The chemical composition on the soil particle surfaces. Hydraulic loading: The more people, the more liquid: more rapid percolation down to the groundwater possible limit loading cover superstructure so that no rain or surface water can flow into the Source: (29) “Pit latrines generally feature a high risk of groundwater contamination, since the liquid parts, containing pathogens, can seep through the ground. This risk depends on several factors: The separation distance to the groundwater is thus a very important hygienic barrier when using pit latrines. This distance should be maximized. The distanced necessary to avoid groundwater contamination will depend on several factors as The soil texture, The soil structure The chemical composition on the soil particle surfaces. Normally finer grained soils (fine sand silt or finer) give better protection than coarser sands and gravel. In ideal cases a separation distance of 1m may be sufficient. Soils with a high content of iron and aluminum oxides (brown or red soils) have better abilities for retention of bacteria and viruses than light colored or organic soils. If the soil have cracks or other macropores as old root channels or worm holes, the risk of rapid percolation pollution to the groundwater and subsequent pollution increase. Abandoned wells and pit latrines may also constitute potential conduits for pollutants to reach the groundwater zone. Another important factor influencing the potential pollution of the groundwater is the hydraulic loading and the construction details of the toilet. The more people that use the toilet the more liquid and potentially more rapid percolation down to the groundwater. In order to maximize the retention time for percolating liquids the loading of the toilet should not be to high. Water should be limited to what is used for anal cleansing and cleaning of the toilet. It is also of extreme importance that the toilet is constructed so that no rain or surface water can flow into the pit both when the toilet is in use and when the pit is full and covered for maturation and hygienization of its content.” Source: (29)

Pour-Flush Latrines Pour-flush toilets: ‘wet’ systems
require water to function. Pit is used for excreta disposal Water seal for odour & fly control not suitable for areas with cold climates and impermeable or very low permeable soils, & areas with high groundwater tables Higher risk for groundwater contamination (more water) should be avoided in areas of shallow water tables Discharge to septic tank systems common “The pour-flush toilets (C) are ‘wet’ systems as they require one to three litres of water per flush to function. They use a pit for excreta disposal and have a special pan, which is cast into the cover slab. They are preferably equipped with a water seal for odour and fly control. Pour-flush toilets are not suitable for areas with cold climates and impermeable or very low permeable soils (2). The potential risk for groundwater contamination is higher than for pit or VIP latrines due to the water use and pour flush toilets should be avoided in areas of shallow water tables where the groundwater is a source of drinking water. Moreover, they are also unsuitable on impermeable grounds, as the liquid cannot drain away. Pour-flush toilets are also inappropriate where the use of solid objects for anal cleansing is the custom as these may cause siphon blockage. The pour flush toilets may be equipped with one or two soakpits. Such toilets may also discharge to septic tank systems.” (29) Source: (29)

Composting Toilets P. Jenssen

Composting Toilets Composting toilets: dry systems collection chamber
Bulking material and proper ventilation reduces or eliminates the excess liquid. With/without urine diversion Aerobic degradation of organic matter. When properly functioning: volume reduction of the excreta is 70-90% On site composting very well possible Composting toilets are dry systems built with a collection chamber where all excreta is confined. The collection chamber is normally constructed without drainage possibilities for excess liquid, however some models have this possibility. In case of drained chambers the effluent should preferably be collected in a container for further storage and safe disposal. Adding sufficient amounts of bulking material and proper ventilation reduces or eliminates the excess liquid. The toilets can be designed with or without urine diversion (8). Composting toilets mainly rely upon aerobic degradation of organic matter. When properly functioning the volume reduction of the excreta is 70-90% (12) – the total volume per person can be as little as 50 to 150 litres per year. With the proper maintenance, it is thus very well possible to keep composing processes on-site, i.e. to sanitise excreta right where they are produced. VERA Miljø Source: (8) A: Single chamber C: Removable Compartments B: Dual chamber Aerobic: Refers to the respiration process of organisms that use free molecular oxygen from air to release the energy from nutrients. Aerobic organisms are 10 to 20 times more efficient than anaerobic organisms. These live in anoxic (without oxygen) environments, and first must digest oxygen-containing chemicals and compounds, using energy in the process (12).

Composting Toilet Use in Urban Areas?
Use of compost toilets in urban areas is debatable. Problems: use of end product? Transport to rural areas? Developed countries: are waterless toilets allowed at all? Developing Countries: urban agriculture possible transport over short distances might be feasible and economically sound Source: (7) The use of compost toilets in urban areas is debatable. Generally speaking, compost toilets are not popular for a variety of reasons, e.g.: the end product is rarely if ever used directly by the urban dweller; transport of the compost material to agricultural areas is often impractical; and, municipal authorities often do not permit waterless toilets for concerns of public health (3). Nevertheless, they do exist in urban settings. Compost toilets were used in Germany’s first ecological settlement (established in 1986 in Hamburg-Allermohe) to demonstrate alternative, decentralized wastewater treatment solutions. Other composting toilet systems followed (total about 500) with some designed for four-story housing (4). However, the situation is different in developing countries. We see recent substantial increase of compost toilets in developing countries. In Der-es-Salaam City, Tanzania, for example, 110 compost toilets were installed in (5). In developing countries, there is generally a higher tendency that the compost can be used on-site for urban agriculture, therefore possibly increasing the food security as well as creating an additional source of generating income (see Module 2-2 “Urban Agriculture”) However, we should keep these facts in perspective. Although urban compost toilets exist, their use and acceptance is more limited than in rural areas.

Composting Toilets – Off-Site Management
On-site treatment : Involves some health risks (handling) Proper information and hygienic behaviour is necessary (using gloves & boots, washing hands… Composting process can be difficult to operate Off-site treatment: Monitored operations More comfort for users Compost process can be properly monitored Reduced health risks Source: (7) Collection of faeces in removable containers Professional Off-site composting of faecal material J. Heeb EcoSanRes On-site treatment of waste from composting toilets involves health risks. The main risk is connected to emptying of the toilet and the subsequent handling/disposal of the waste resource. However, with proper training/information to the person responsible these risks are minimized. The main protection measures involve using gloves and boots when handling the toilet waste and proper washing of hands and equipment after the job. It is also important dispose of the material without reach of people; children especially. Usually burying the material or covering the material with soil will be sufficient. In essence, composting toilets require more maintenance than dehydration toilets. And composting large volumes of excreta requires managed operating procedures. It can therefore be suitable to collect the accumulated, partly decomposed faeces (see option C) and compost them off-site. Off-site treatment might even have the advantages that toilet maintenance and recycling excreta would be neither ad hoc nor voluntary. Operations would be monitored, structured, continuous and regulated. Operation and management will require trained (and supervised) personnel, but the benefits are; simplified operation for the toilet user, reduced health risks for the toilet users and for the users of the end product since the excreta is professionally handled. Since the volume of human waste in urban areas far exceeds any method of depleting it, composting appears a sustainable way of exploiting this rich natural resource.

Where are composting toilets used?
Composting toilet at roadside facility – Sweden, elected the best roadside facility In Sweden 2002 “Compost toilets are traditionally used in rural environments, both in developing and industrialized countries. In developing countries, they often serve as the basic toilet facility for year-round residential homes, and, to a lesser extent, as a public facility. In industrialized countries, they are typically associated with seasonal vacation homes. In the former case, compost toilets tend to be home-built or prefabricated assemblages from local material; in the latter case, they are generally manufactured units, which may (or may not) be required to meet regulatory standards.” (7) P. Jenssen P. Jenssen

Composting Toilets – Management
Continuous process: fresh and matured material is in the same container Higher health risk than dual chamber Double vault system: Use of only one vault at time – content of other vault matures undisturbed safer for persons emptying the toilet. facilitates professional collection and secondary composting Composting systems may be operated either in a continuous (A) or batch (B and C) mode. In a continuous process the fresh and matured material is in the same container. This increases the risk of contact with fresh faecal material when emptying the toilet. In a batch operated system the as the double vault system (B) one vault is used while the other matures or the collection containers (C) are changed when full and set aside for maturation and hygienization. This eliminates mixing of fresh and matured material and is safer for persons emptying the toilet. A batch operation also facilitates professional collection and secondary composting (6). Secondary composting may be a way to ensure proper hygienization of material from composting toilets. VERA Miljø Source: (8) A: Single chamber B: Dual chamber C: Removable Compartments

Treatment: On-site/off-site dry composting
P. Jenssen

Treatment: Composting Toilets – Dry Composting Process
Composting is a biological process: Decomposition and mineralization mainly by aerobic processes. Generates heat: but rarely above 50°C Pathogen destruction: mainly through temperature Efficiency of composting depends upon (1) the volume of mass, and, (2) managing environmental factors, including: Moisture Carbon to nitrogen ratio aeration, temperature management and a large numbers of diverse organisms (such as bacteria to decompose faeces, fungi to decompose paper, and, to a lesser degree, arthropods and worms to help aerate). Source: (7) “Composting is a biological process. In contrast to dehydration toilets, which are based on physical processes, Composting systems can turn the nutrient-rich excreta into a valuable soil conditioner and fertiliser. Organic matter is decompose and mineralize mainly by aerobic biological processes. The composting process generates heat, but it is seldom that temperatures in composting toilets exceed 45. Pathogens are destroyed various ways, but generally speaking, composting relies upon high temperatures (> 45°C) to sanitize the waste rapidly. Storing excreta long enough, say two years, will produce a safe product. But the efficiency of composting depends upon (1) the volume of mass, and, (2) managing environmental factors, including: Moisture Carbon to nitrogen ratio aeration, temperature management and a large numbers of diverse organisms (such as bacteria to decompose faeces, fungi to decompose paper, and, to a lesser degree, arthropods and worms to help aerate). In essence, composting toilets require more maintenance than dehydration toilets. And composting large volumes of excreta requires managed operating procedures. It can therefore be suitable to collect the accumulated, partly decomposed faeces (see option C) and compost them off-site.” For more information on temperature see the ++ part after the “END OF MODULE 3-1” slide. Source: (7)

++ Glossary: Temperature (short)
Aerobic Decomposition in composting: Below 5°C is biological zero – little to no active processing takes place From 6°C to 20°C, psychorophilic (ambient) processing (mouldering) takes place. From 21°C to 45°C, mesophilic bacteria are dominant. These are the typical bacteria in a a composting toilet. From 46°C to 71°C, thermophilic bacteria take over, and push the process to the limit. Source: The Composting Toilet Book (12) Aerobic Decomposition in composting: Below 5°C is biological zero – little to no active processing takes place From 6°C to 20°C, psychorophilic (ambient) processing (mouldering) takes place. From 21°C to 45°C, mesophilic bacteria are dominant. These are the typical bacteria in a a composting toilet. From 46°C to 71°C, thermophilic bacteria take over, and push the process to the limit. Source: The Composting Toilet Book (12) Note that these definitions are not absolute. Other scientists use slightly higher or lower temperature ranges to refer to the above mentioned terms. These numbers should just give you a general idea of what the different temperature ranges refer to.

Ideal moisture content for composting: 50-60%. Excreta more than 90% moisture, faeces alone 65% and 80%.  adding dry bulking material for proper functioning!! absorbs excess make the pile less compact, coverage from flies reduces odour  proper ventilation is very important Carbon to nitrogen ratio Including urine, it is 7 parts of carbon to 8 parts of nitrogen For good composting the carbon to nitrogen ratio should be between 30 and 35. add carbon rich bulking material (toilet paper, wood or bark chips, sawdust, ash odour problems. adding of organic household waste also possible Source: (29) “The ideal moisture content for composting is 50-60%. Excreta has a moisture content of more than 90% and faeces alone 65% and 80%. Thus, adding dry bulking material becomes an important part of operating a composting toilet with or without urine diversion. If bulking material is not added the toilet will not function as a composting toilet, but will be a collection chamber for wet excreta. Ideally bulking material should be added to the chamber after each use to absorb excess moisture, make the pile less compact, and make it visually more acceptable for the next user. It is also important to assure proper ventilation both for odour control and for evaporation of moisture. The ideal ventilation is as for the VIP toilet down through the toilet and out through the ventilation chimney. This can be obtained using a electric or wind driven fan. Extending the chimney above the highest point of the roof and painting it black above the roof also helps passive ventilation. The carbon to nitrogen ratio (C/N-ratio) of excreta (including urine) is 7-8. For good composting the carbon to nitrogen ratio should be between 30 and 35. The C/N-ratio can be elevated by adding bulking material, such as toilet paper, wood or bark chips, sawdust, ash or other similar substances. The bulking material also serve to cover the fresh faeces and thus lower the potential of fly contact and fly breeding in the toilet, thus, reducing the risk of disease transmission. Adding bulking material also helps mitigating odour problems. Organic household waste can also be added to a composting toilet through the toilet or in a separate chute (see A slide 18). Adding organic household waste will help to rise the C/N ratio.“ Source: (29)

Temperature (0C) Temperature: some viruses and bacteria already die after 1 hour of treatment at 65°C, others show slower die-off rates. High temperatures difficult to reach, rarely above 40°C: secondary composting or storage period needed to get safe product 1 day 1 week 1 month 1 year 70 45 65 60 55 50 40 35 30 25 20 Shigella Taenia Ascaris Vibrio cholerae Salmonella Hookworms Temperature: “Thermophilic composting of faecal material produces significant reduction in pathogens. Whereas some viruses and bacteria already die after 1 hour of treatment at 65°C, others show slower die-off rates. Due to its complexity however, the composting process may prove difficult to manage within the chamber and there have been reports of badly designed and managed systems resulting in a T90 reduction (time for a 90% inactivation of organisms) in the total viable pathogen content taking two months, with the number enterococci actually increasing.” (10). “In reality composting toilets do not reach thermophilic temperatures. Experience from temperate regions has shown that it is difficult to reach temperatures above 40°C in the composting compartment. The normal operating temperature is therefore mesophilic or ambient. Unless long maturation times are used (see table on the left) it may be necessary to give the material a secondary composting or storage period, in order to get a safe product for agricultural reuse.“ (10) For more information on temperature see the ++ part after the “END OF MODULE 3-1” slide. Influence of time and temperature on the destruction of selected pathogens in excreta Time Source: (29)

Recommendations for storage treatment of dry excreta and faecal sludge before use at the household and municipal levels. No addition of new material Treatment Criteria Comment Storage; Ambient temperature 2-20°C 1.5 – 2 years Eliminates bacterial pathogens; re-growth possible; reduces viruses & parasitic protozoa below risk levels. Some ova may persist Ambient temperature >20-35°C > 1 year Inactivation of Clonorchis and Opisthorchis eggs within days, substantial to total inactivation of viruses, bacteria and protozoa; survival of a certain percentage (10-30) of Ascaris eggs (≥4 months) Alkaline Treatment pH >9 during >6 months If temperature >35°C and moisture <25%. Lower pH and/or wetter material will prolong time for absolute elimination. Source: Adapted from: (29)

Dehydration Toilets P. Jenssen

Dehydration Toilets Construction similar to compost toilet
Source: GTZ Construction similar to compost toilet Aim: dry out excreta Reduction of moisture content by heat (solar) natural evaporation ventilation addition of absorbent materials. Popular in arid climates High temperature in the chamber, together with effective ventilation speeds up the desiccation process. Humidity, temperature, storage time & pH play important role in pathogen Source: (14) “A dehydration toilet is in principle constructed as a composting toilet with a collection chamber below the toilet. The aim, however, is to evaporate or dry out the excreta instead of optimizing the conditions for composting. In the dehydration toilet, the moisture content of the excreta is reduced with the aid of heat (preferably solar), natural evaporation, ventilation and the addition of absorbent materials. This technology is increasingly popular in arid climates where water is scarce and faeces can be effectively dried. High temperature in the chamber, together with effective ventilation speeds up the desiccation process. Together with temperature and humidity the storage time and the pH all play an important role in the reduction of pathogens.” Source: (14)

Dehydration Toilets – Process & Management
Absorbents: Lime Ash dry soil Sawdust Etc… Addition of absorbents reduces flies eliminate bad odours May increase pH Note: toilet paper or similar objects placed in the chamber will not disintegrate quickly  collect material separately Double-vault dehydration toilet in Ecuador with inclined lids to increase the solar heating effect (Esrey et al., 1998) The faeces are collected in a chamber below the toilet (or squatting hole) and are dried. “Absorbents such as lime, ash, or dry soil should be added to the chamber after each defecation to absorb excess moisture, make the pile less compact and make it less unsightly for the next user. Addition of absorbents is also reported to reduce flies and eliminate bad odours. Moreover, depending on the additive, the pH may also be increased due to this addition, and hence enhance bacterial pathogen die-off. As breakdown of organic material in dehydrating conditions is slow, toilet paper or similar objects placed in the chamber will not disintegrate quickly. Toilet paper can therefore either be handled separately, or be composted in a secondary treatment process. Once the chamber is almost full, the content may need to be removed. The contents are further stored, used as a soil conditioner, buried or composted (in home composting or at a local composting centre).” Source: (14) Source: (14)

Dehydration Toilets – Available Technologies
Urine diversion or non-urine diversion Urine diversion facilitates reuse and reduces moisture content Use or disposal of urine use of collected urine as a fertiliser recommended Single vault or double vault double vault systems involve smaller risks in handling Ventilated vault or not Ventilation is recommended to enhance the drying process. Dry or wet anal cleansing: Wet anal cleansing possible  liquid can be drained in a separate pipe and treated separately Source: (14) “Many alternative ways of constructing dehydration toilets exist. Generally double- vault toilets with urine diversion have shown the most successful results and the highest popularity. Several modifications have been applied to enhance the dehydration process and to suit each region’s condition. The main distinguishing features are listed in the following. Urine diversion or non-urine diversion Most dehydrating toilets require prior separation of urine to allow sufficient drying of faeces. Systems where urine and faeces are mixed only work properly in very dry climates. Drainage system for the chamber can also improve improve dehydration of the solids. Urine diversion systems not only allow the separate collection of nutrient rich and virtually sterile urine, but also greatly reduce the odour problems associated with dry mixed systems. Use or disposal of urine The use of separately collected urine as a fertiliser after appropriate storage is strongly recommended, due to its high nutrient concentration and the low associated health risks. However in certain circumstance urine use may not be acceptable or immediately possible and urine is infiltrated directly to the soil via a soak-away pit. Single vault or double vault Dehydration toilets can be built with a single or a double chamber for collection of faeces (See B slide 18). By using a double-vaults, handling of fresh excreta can be avoided, as the vaults are used alternately, with sufficient time allowed for the faeces to sanitize. Single-vault systems may be less expensive to build, but need more labour to guarantee the same hygienic safety as double-vault systems. Ventilated vault or not Ventilation is generally recommended to prevent odour and flies and to enhance the drying process. If the toilet is constructed within the house, a vent pipe is strongly recommended due to the reduced smell and flies problems. Ventilation through installed pipes can be natural or enforced by wind propelled or electrical fans.” “Squatting or sitting There are numerous technologies that suit both defecation styles (squatting or sitting) with simple drop holes or specially designed urine diversion squatting pans for squatting cultures (e.g. Vietnamese toilets and Chinese squatting pan) or urine diversion seat risers for sitting cultures (Central America, Europe and parts of Africa). Dry or wet anal cleansing Dehydration toilets can receive dry cleaning materials such as toilet paper (which however, will not decompose completely). Dehydration toilets can also be used for wet cleaning cultures, water from anal cleaning then has to be drained in a separate pipe so that no liquid is led into the vault. Self-built or prefabricated Most systems can be self-built by the users totally or partially using commercially available squatting pans or toilet seats. In some areas, complete systems including the toilet cabin and the substructure are available on the market.” Source: (14)

Dehydration Toilets – Applicability
Climate: Mainly suitable for regions with high average temperatures, long dry and short rainy seasons or arid climatic conditions Application in humid climates possible (solar powered heaters) Rural and urban areas Application both in urban and rural areas possible “Dehydration toilets have been applied in various, mostly developing countries, including China, Vietnam, India, Nepal, Mexico, Ecuador, El Salvador, South Africa, Zimbabwe and many others. Climates Dehydration toilets are mainly suitable for regions with high average temperatures, long dry and short rainy seasons or arid climatic conditions with high evaporation rates. Nevertheless, with simple solar heaters, they can also work in a more humid climate. Dehydration toilets are waterless systems that are particularly suitable for conditions where water is scarce. Rural and urban areas Dehydration toilets can be placed outside the house, attached or even inside to house. Dehydration toilets are therefore suitable both for rural and densely populated urban areas.” (14) Source: GTZ Source: GTZ Source: GTZ Dehydrating School Toilet Facility, China two chamber system Rear view of a dehydrating toilet, Mali

Treatment: Dehydration Toilets - Process
P. Jenssen

Treatment: Dehydration Toilets - Hygienization
Few studies Ascaris eggs: particularly resilient to dehydration Pathogen reduction dependent on temperature, moisture content and pH, Re-growth of pathogens is possible if the material is rewetted Secondary treatment (composting) may be recommendable There are few studies reporting the pathogen die-off rate in dehydrating toilets. The available studies indicate that Ascaris eggs are particularly resilient to dehydration (11, 12). Dependent on the temperature, moisture content and pH, 6-12 months in warm climates are usually sufficient to allow for the die-off of nematode eggs (13). Other investigations (Stenström, 1999) in Vietnam have shown that a 6 month retention period can give a sufficient reduction of resistant indicator viruses and Ascaris eggs. However, dehydrating pathogenic bacteria can prompt certain pathogens to produce endospores, essentially a form that can survive for decades until rehydrated, when they would return to their full potency. The eggs of the parasite Ascaris lumbricoides have been viable for years in a dry environment. Also, the nutrients in the dried, unoxidised matter are not available to plants. Dried organic matter will require biological processing before plants can use its nutrients safely (12). Further storage, sun drying, alkaline treatment or high-temperature composting are recommended to further decrease health risks of utilization of the dehydrated faeces (14).

Urine Diversion Toilets
P. Jenssen

H,-P. Mang J. Heeb Source: GTZ Urine diverting slab toilet, e.g. used in China Urine diverting slab toilet, e.g. used in India Single Flush Urine Diversion Toilet, Sweden Double Flush Urine Diversion Toilet, Sweden Urine diverting insert to a bocket toilet “Urine diversion is principally a collection system of separating human urine at the source before it mixes with faeces. This is achieved with specially designed toilets and urinals, piping systems and storage containers. The collected urine, loaded with essential plant nutrients, can then be further processed and used as a local fertiliser in agricultural production, thus closing the nutrient cycle. By separating urine from faeces, separate treatment options can also ensure a more manageable faecal fraction and reduce potential odours.” (17)  Separating human urine at the source before it mixes with faeces.

Potential to recover the majority of the nutrients from the wastewater 80% of the Nitrogen (N), 55% of the Phosphorous (P), 60% of the Potassium (K) as well as a substantial fraction of Sulphur and Magnesium in urine Minimal hygienic risk Recent interest in hormones and pharmaceuticals Low risk if applied to soil Environmental benefits: nutrient pollution of ground- and surface reduced. reduces the nutrient load of the wastewater stream Significant water savings (up to 40 l/person/day, or 50% (18) possible Energy saving potentials (decrease in use/production of artificial fertilizer) “Source-separating human urine dates back thousands of years with Chinese farmers using urine as a liquid fertiliser. With complete urine diversion, one has the potential to recover the majority of the nutrients from the wastewater stream; 80% of the Nitrogen (N), 55% of the Phosphorous (P), 60% of the Potassium (K) as well as a substantial fraction of Sulphur and Magnesium. This equates to approximately 11g N, 1g P, 2.5g K per person per day, depending on a persons diet (18). Results may vary with population and diet. On average 1,5 litres of urine can be collected per person per day. Numerous urine diversion technology options are available to meet the socioeconomic and cultural demands of the people as well as the climatic and technical conditions of the location. Waterless appliances make urine diversion a suitable option in water scarce regions. With proper management urine diversion systems offer minimal hygienic risk. With a very low heavy metal concentration and minimal faecal contamination, urine can easily be treated and sanitised for application as a quality plant fertiliser. Recent interest in hormones and pharmaceuticals excreted with urine has prompted further studies on their persistence and behaviour within natural ecosystems. However, it is assumed that applying these substances to aerobic, biologically active soil layers will result in a much faster degradation, than discharging them into water bodies (as is currently practised). See M4-7 Tutorial for more details on this issue. Urine diversion offers numerous environmental benefits: nutrient pollution of ground- and surface waters can be significantly reduced. reduces the nutrient load of the wastewater stream improving treatment performance potential. Significant water savings (up to 40 l/person/day, or 50% (18)) are possible with reduced flush demands compared to conventional flush toilet (WC). Energy saving potentials (decrease in use/production of artificial fertilizer)” Source: (17)

Single-Flush Urine Diversion Toilets
urine flushed with less than 0.5 litres double flush both the urine and faecal matter flushed (2-4litres) Maintenance: facilitated if there is access to the faecal collection chamber from the outside of the building  professional collection possible Ventilation: important to avoid smell (single flush) Organic filters (soil/peat) available much less odour than if urine & faeces are collected together Collected faecal matter: dry  but proper ventilation necessary Winblad & Simpson-Hébert (15) Modern urine diversion toilets come in two versions; 1) single flush where the urine is flushed with less than 0.5 litres and 2) double flush where both the urine and faecal matter is flushed. The dual flush toilets are usually 2-4 litre toilets ( litres for urine, dependent on toilet type - and 4 litres for faecal matter). “Maintenance of the toilet is facilitated if there is access to the faecal collection chamber from the outside of the building. This eliminates handling of faecal matter inside the building and opens for professional collection and emptying of the toilet, thus reducing the overall risk of handling faecal matter. As with composting toilets the ventilation of the toilet room using a single flush urine separating toilet is important to avoid smell. The used air should pass down through the faecal collection chute. The exhaust air from the faecal collection chamber should be expelled above the roof of the house. Alternatively a small organic filter (soil/peat) can be used to filter the air. However, odour from the faecal collection chamber of a urine separating toilet has very little odour compared to a composting toilet where both urine and faecal matter is collected. The collected faecal matter of a single flush urine separating toilet is dry and will become drier if the collection chamber is properly ventilated. Composting and stabilization of the faecal matter does therefore not take place in the collection chamber. A proper stabilization and hygienization of the collected faecal matter is dependent upon proper composting after collection.” (7)

Single-Flush Urine Diversion Toilets
“Because of a technical constraints (a straight chute for the faecal matter) it may be difficult to use single flush urine diversion toilets in multi storey buildings, but when integrated in the original design single flush urine diversion toilets have been used in four storey apartment buildings.” (15) Source: Ecosanres/SEI

Dual-Flush Urine Diversion Toilets
P. Jenssen P. Jenssen Examples of two Swedish dual-Flush Urine Diversion Toilets Wost Man Ecology “In the dual flush system the faecal matter is flushed away thus requires a sewer system. Dual flush systems can be fitted in both new and existing urban areas with multi storey buildings. In existing buildings a gravity urine collection system must be fitted for each building. Within pedestal toilets, a pan generally located towards the front of the defecating area collects the urine. This may require men to sit whilst urinating for the system to work correctly. If this should prove problematic, urinals can be used to collect urine from male users.” Source: (29) Dual flush system: faecal matter flushed away  requires sewer system. Can be fitted in both new and existing urban areas with multi storey buildings. Source: (29)

Dual-Flush Urine Diversion Toilets
Scheme of building equipped with double-flush Urine-Separating Toilets. Urine is flushed with about liters, whereas faeces are flushed away with roughly 4 litres, and are usually treated in a conventional sewage treatment plant. The collected urine can be stored and reused in agriculture (16). P. Jenssen

Waterless Urinals Waterless Urinals at Kastrup airport, Copenhagen
P. Jenssen Waterless urinals have been used for a long time. Their development was particularly driven by the needs of arid areas, where water is too vital to waste to simply transport urine. These urinals have been used for quite some time in industrialised countries. Here the motivation mainly is economic to reduce the costs of water supply, particularly in highly frequented buildings. Waterless Urinals at Kastrup airport, Copenhagen

Waterless Urinals Collect undiluted urine
Low flush urinals also available good acceptance for both systems, as they require no change in behaviour Addicom Source: GTZ Simple slab urinal Liquid stench traps: urine passes through a liquid odour lock which is lighter than urine Reduces odour Environmentally friendly Source: (17)

Treatment: Urine Storage
P. Jenssen

Treatment: Urine Storage
Urine:  Low risk for infection  Faecal cross contamination = highest risk P. Jenssen Urine Storage Tank at Lake Bornsjön in Sweden. Storage minimizes hygienic risks eliminates or reduces the number of pathogens Greater elimination at higher temperatures & longer retention times Urine is generally considered safe to be used on products which are not consumed raw after a storage time of 6 months at temperatures above 4°C (19) Urine in itself presents virtually no risk of infection. But it can be contaminated by pathogens present in faeces. However, if appropriate measures and precautions are taken, and if the recommendations for storage and application are followed, the hygienic risks associated with urine separation are very small. The urine is stored in tanks in order to minimize hygienic risks; Storage eliminates or reduces the number of pathogens in the urine. The reduction is greater if the urine is stored for a long time, at high temperature, with a high concentration of nitrogen and a high pH level in the solution. Storage is an effective means of sanitising diverted urine. This can be explained by the fact that nitrogen in fresh urine is present in the form of urea. In concentrated urine, the concentration of urea-N is typically 6 to 11 g/l and has a pH of 7. During transport in pipelines, urea breaks down to ammonia and carbon dioxide which results in a pH increase to between 8.9 and 9.2 (22). Ammonia is toxic to microorganisms and the amount of NH3 generated increases with temperature, pH and the concentration of NH4+ in solution. The combination of increased pH and generation of ammonia effectively hygienises urine. Urine is generally considered safe to be used on products which are not consumed raw after a storage time of 6 months at temperatures above 4°C. (19) Adapted from: (7) For more information see Module M4-7 Adapted from: (7)

Watersaving Toilets P. Jenssen

Water-Saving Toilets (vacuum and gravity)
Low Flush Toilets very small amount of water, sometimes less than 1 litre per flush. operated by gravity or vacuum. Large water savings are thus possible: collection of blackwater possible Risk of pipe clogging Roediger/OrbitPupms Water Connection Opening for Bucket filling Puller for Flushing Cistern Seat Cover Image Source: The Gustavsberg, Miniflush, and the Roediger Mark 5 Toilet which works with 1 litre per flush Low Flush Toilets work with a very small amount of water, sometimes less than 1 litre per flush. These toilets can operate by gravity or vacuum. The gravity toilets usually, this works with a valve that opens at the moment the flushing button is pressed. However, these toilets have special requirements regarding the slope of the pipe. Large water savings are thus possible, which even facilitate the separate collection and reuse of blackwater. Moreover, if the gradient to the public sewer systems is steep enough, extremely low-flush toilets can also be retrofitted into existing buildings. However, there is a risk of pipe clogging.

Water-Saving Toilets (vacuum and gravity)
Evac Marine Systems: Vacuum Toilet squatting platform Vacuum Toilet liters/flush - floor mounted Vacuum Toilet liters/flush - wall mounted (Jets) Vacuum technology: long since applied as a sewage collection tool in ships, trains and aircrafts collect blackwater (urine and faeces together) as concentrated as possible for further processing and reuse in agriculture. Vacuum toilets use 0.5 – 1.5 litres per flush Smaller pipes than conventional gravity sewerge Dry matter content: <1%  addition of organic matter (i.e. grinded organic household wastes Completely closed system “The vacuum technology has been applied as a sewage collection tool in ships, trains and aircrafts for years. However, it can also be used in domestic technology for wastewater collection and transport. Vacuum as well as low flush gravity toilets are used to collect blackwater (urine and faeces together) as concentrated as possible for further processing and reuse in agriculture. Vacuum toilets use 0.5 – 1.5 litres per flush, newly developed gravity toilets using down to 1 litre per flush exist as well (slide 51). However, the 1-liter gravity toilets require standard pipe dimensions and special care regarding slope of the pipe system and horizontal transport distance. Blackwater collected using 1-liter per flush toilets has a dry matter content not higher than 1% (20). In order to successfully treat the blackwater aerobically or anaerobically (see further down) additional organic matter must be added. It is therefore beneficial to add grinded organic household waste to the blackwater holding tank. The use of vacuum toilets provide an equal level of comfort compared to traditional flush toilets, but is possibly more hygienic due to air sucked into the toilet when flushing and thereby avoiding aerosols. The system is completely closed and should a leak occur, the negative pressure in the pipes reduce the risk of raw sewage spill. Vacuum toilet systems can be installed in multi-storey buildings in urban situations.” Source: (29) Source: (29)

Blackwater volumes The collection volume will depend on the flush volume: Source: (7)

Vacuum Toilets in a source separating system
Figure: P. Jenssen Figure of a building equipped with vacuum toilet technology. Here, the concentrated blackwater is collected by a vacuum truck after organic household waste (OHW) has been added; it is then hygienised through aerobic or anaerobic digestion. The sanitised sludge can be used as a fertilizer in agriculture. Additionally, urine separating vacuum toilets are being developed, so that the urine fraction, which is hygienically less critical, can be reused in agriculture after a storage period. The figure above also implies the separate treatment and reuse of greywater. Greywater, due to its large volume, cannot be collected, but must either be treated onsite or discharged into the sewer system. The use of watersaving household appliances avoids unnecessary dilution of the flow streams. This minimises the consumption of valuable drinking water and produces high concentrations of recyclables.

Strengths and Weaknesses of Vacuum Toilets
Health impact No leakage Highest hygienic safety (closed system) No pathogen contamination of the groundwater Reduction of wastewater flows Environmental impact Tool for integrated ecological concepts such as energy recovery (biogas) No leaks Water savings Reduction of wastewater flows through sewers and wastewater treatment plants Additional energy for operation required Socio-cultural suitability Same comfort as gravity No odour nuisance Correct construction, operation and maintenance required Costs and benefits 20 to 25% cheaper than conventional sewerage Due to water savings amortisation possible within few years CVS normally use more energy than a gravity toilet may have a higher installation cost Technical Ductile, lightweight material, ease of installation and handling No slope requirements Shallow and narrow trenches High flexibility according to appearing obstacles Correct construction, operation and maintenance required V ulnerable to power outages Strengths Weaknesses Health impact No leakage Highest hygienic safety (closed system) No pathogen contamination of the groundwater Reduction of wastewater flows through sewers and wastewater treatment plants Environmental impact Tool for integrated ecological concepts such as energy recovery (biogas) from blackwater possible High security against leakage of wastewater (no nutrient and pathogens) Water savings Additional energy for operation required Socio-cultural suitability High Tech provides the same comfort than gravity No odour nuisance Correct construction, operation and maintenance required Costs and benefits 20 to 25% cheaper than conventional sewerage due to easy construction without heavy machinery Due to water savings amortisation for vacuum sanitary installations within few years is possible Constant vacuum (CVS) toilet systems normally use more energy than a gravity toilet Vacuum sanitary installations may have a higher installation cost Technical Ductile, lightweight material, ease of installation and handling No slope requirements Shallow and narrow trenches High flexibility according to appearing obstacles Correct construction, operation and maintenance required High Tech – vulnerable to power outages Source. (33)

Vacuum Sewer Systems 20 to 25 % less costly to construct than conventional sewers  construction is much easier Narrow trenches slope can be made in a saw-tooth profile Easy to over-/underpass obstacles Integration into existing sewer systems possible Vacuum sewer systems are 20 to 25 % less costly to construct than conventional sewers, because the construction is much easier – trenches do not have to be very deep and wide (vacuum pipes are normally of smaller diameter than gravity sewers (7) , the slope can be made in a saw-tooth profile, thus not requiring a constant gradient. Moreover, it is not very difficult to under- or overpass obstacles (20). In addition, vacuum sewer systems can also be incorporated into existing sewer systems, e.g. if the conventional pipe system is leaking and would need a large-scale renovation. In that case, it is possible to lay out the vacuum pipes in the existing sewers, which can be cheaper than refitting and sealing all existing leaks.

Vacuum Sewer Systems Functioning Principle:
Wastewater flows to the low point In the low point wastewater is collected, closing the pipe-diameter. When air is admitted through an upstream interface valve, plugs are accelerated and pushed over the high points towards the vacuum station Source: (20)

Vacuum Systems for the Collection of Blackwater
Vacuum 50-63mm Gravity 110mm Vacuum pipes are normally 50 or 63 mm in diameter. When rehabilitating or upgrading older buildings to a higher sanitary standard using a vacuum toilet system may be cheaper than a gravity system because of the flexibility of the vacuum piping and the lesser diameter piping. Source: (7) P. Jenssen

Vacuum Sewer Systems Separate collection of black and greywater possible Collection chamber Vacuum Station Graphics: Roediger Vacuum sewer systems can be designed to collect both black and greywater together as shown below. In ecosan, which normally implies source separation, vacuum toilet systems for gives the opportunity to collectconcentrated blackwater. Main components of vacuum sewerage system: Vacuum station which creates low pressure Vacuum sewer line for transport of sewage Collection chambers with interface units (not needed in a system collecting blackwater using vacuum toilets) Source: (21) Source: (21)

Vacuum Systems Vacuum systems are dependent of a vacuum generation unit. In principle there are three different designs: Vacuum collection tank with vacuum pump : original design. can operate a short while without power to the pump (large reservoir) Ejector with atmospheric collection tank The vacuum generation by an ejector is produced by circulating sewage through an ejector. large volumes have to be pumped  avoid temperature rise Vacuum generating and forwarding pumps (vacuumarator) generates vacuum on the inlet side which is connected to the vacuum piping and the toilet discharges the wastewater under pressure in the other end. able to transport the blackwater to an atmospheric holding tank that is at a higher elevation than the arator. Vacuum systems are dependent of a vacuum generation unit. In principle there are three different designs: Vacuum collection tank with vacuum pump Ejector with atmospheric collection tank Vacuum generating and forwarding pumps (vacuumarator) The vacuum collection tank with vacuum generator is the original design. Because of the vacuum tank this system has a large vacuum reservoir and can operate a short while without power to the pump. The vacuum generation by an ejector is produced by circulating sewage through an ejector. In order to avoid temperature rise in the recirculated sewage, relatively large volumes have to be pumped. The vacuumaerator is a unit which generates vacuum on the inlet side which is connected to the vacuum piping and the toilet and discharges the wastewater under pressure in the other end. When the blackwater enters the arator it is macerated, then it runs through the arator and is expelled on the pressure side. The arator is able to transport the blackwater to an atmospheric holding tank that is at a higher elevation than the arator. Source: (7) Source: (7)

Vacuum Systems 1. Vacuum collection tank with vacuum pump
Vacuum collection tanks with vacuum pumps are normally used for larger installations and constant vacuum systems. The vacuum pump generates sub-atmospheric pressure within the vacuum tank. Due to the vacuum tank, this system has a large vacuum reservoir and can operate a short while without power to the pump (7). Wastewater is evacuated from vacuum toilets or interface units, which are used to connect the greywater (washbasins, bathtubs, sinks and showers) to the vacuum system). The wastewater pump then discharges the wastewater into a tank for further treatment (discharge into municipal sewer is also possible). A level sensor, integrated in the tank, controls the operation of the wastewater pump. In ecosan systems the black and greywater would normally be separated. Adapted from (21) Graphics: Roediger Adapted from: (21)

Vacuum Systems Vacuum generating and forwarding pumps (vacuumarator)
generates vacuum on the inlet side which is connected to the vacuum piping and the toilet discharges the wastewater under pressure in the other end. able to transport the blackwater to an atmospheric holding tank that is at a higher elevation than the arator. Jets Standard 2. Vacuum generating and forwarding pumps (vacuumarator) The vacuumaerator is a unit which generates vacuum on the inlet side which is connected to the vacuum piping and the toilet and discharges the wastewater under pressure in the other end. The vacuumarator due to the simplicity of the system facilitates small single house/toilet systems. The picture to the left (below) shows the smallest vacumarator unit available. This unit is also available for operation by solar power Note the small diameter tube on the discharge (pressure) side. The picture to the right below shows a dual vacuumarator unit in a constant vacuum system with capacity for 50 toilets. P. Jenssen

Vacuum Systems Vacuum on Demand (VOD)
Vacuum is generated only when flushing available in a solar powered version consumes little energy (<10 kWh/person/year) VOD is very flexible and more robust than earlier vacuum systems For use in buildings with no water and/or high voltage electricity supply: solar powered Facilitates local sewage treatment For connection to holding tank. VOD system - with one toilet connected 9 more toilets can be connected to the smallest commercial unit available. For connection to public gravity sewer Jets 3. Vacuum on Demand (VOD) The latest development is vacuum on demand (VOD), i.e., vacuum is generated only when flushing.. The system, which is also available in a solar powered version, consumes little energy (<10 kWh/person/year). The VOD is developed for use in a single house or cabin, and for installations of up to toilets connected to one unit. The VOD is very flexible and more robust than earlier vacuum systems. The robustness is due to the flexibility and ease of serviceability of the smaller units and increased tolerance of air leaks. Toilets are connected to a vacuumaerator, which evacuates the wastewater and discharges it to the a holding tank for further processing to hygienised fertilizer (see slides below) or to a public gravity sewer (32). VOD systems are very flexible and can be applied different situations (Jets Standard):

Treatment: Treatment of blackwater fractions and organic waste
Septic tank sludge: removed from septic tanks needs to be hygienised before recycling to agriculture. Aerobic conditions: Organic wastes are broken down yielding mineralized non-organic components (e.g. NH4+, NO3-, PO43-, CO2, CH4, H2O) and soil humus by a variety of bacteria and fungi. Organic carbon  carbon dioxide Anaerobic conditions organic carbon  methane gas, Gas can be burned as an energy source (biogas) Nutrients such as soluble nitrogen compounds remain available  fertiliser On-site and off-site treatment possible Source: GTZ “Septic tank sludge is sludge removed from septic tanks receiving greywater or combined grey- and blackwater. Faecal sludge is sludge pumped from septic tanks receiving blackwater or the content from pit toilets. The term faecal sludge is also used for sludge from septic tanks receiving combined wastewater. Blackwater and septic/faecal sludge contains faecal matter and needs to be hygienised before recycling to agriculture. Hygienization can be achieved using a variety of methods. Organic wastes are broken down yielding mineralized non-organic components (e.g. NH4+, NO3-, PO43-, CO2, CH4, H2O) and soil humus by a variety of bacteria and fungi. The biological processes involved can take place in the presence of oxygen (aerobic) or in the absence of oxygen (anaerobic). Under aerobic conditions, organic carbon in waste materials is fully oxidised to carbon dioxide by decomposer organisms. Under anaerobic conditions, organic carbon is more likely to be reduced to methane gas, although the generation of a small quantity of carbon dioxide is possible. This gaseous mixture of methane and carbon dioxide, which can be burned as an energy source, is commonly called biogas. The controlled decomposition of organic wastes to produce biogas fuel is therefore an attractive feature of anaerobic treatment processes. In addition, nutrients such as soluble nitrogen compounds remain available in anaerobically treated sludge, providing a valuable source of fertiliser.” (7) Both processes can either take place on-site (e.g. to treat the blackwater of a small cluster of houses) or off-site, i.e. when the blackwater is carried to the treatment facility by the means of vacuum trucks.

Treatment: Aerobic Treatment (Liquid Composting)
P. Jenssen

Treatment: Aerobic Treatment (Liquid Composting)
P. Jenssen Aerobic treatment of liquid organic waste is also termed liquid composting. bubble air through the organic slurry. microbial degradation process by aerobic organisms, mainly bacteria. exothermic process: thermophilic temperatures are reached adding of organic household waste / farm waste to increase dry matter content Aerobic treatment of liquid organic waste is also termed liquid composting. The process is to bubble air through the organic slurry. This starts a microbial degradation process by aerobic organisms, mainly bacteria. The process is exothermic, which means that the process generates heat. In a properly constructed system thermophilic temperatures are reached without additional heat sources, provided the organic content is sufficient. In commercial systems treating blackwater, faecal sludge and organic household waste dry matter (DM) contents down to 1% has been sufficient to reach thermophilic temperatures (23). Ideally the DM-content should be 2 – 10%. A variety of different organic waste material (i.e. organic household waste, animal slurry etc.) can be processed and it is possible to construct the system to run with a net energy surplus (24). For more detailed information on liquid composting, see M3-1 Tutorial, Slides 65/66.

Treatment: Anaerobic Treatment (Biogas Production)
P. Jenssen

Source: GTZ Anaerobic digestion biological process in absence of air endothermic process: consumes heath organic material broken down by microorganisms Final products: water, biogas (a mixture of methane, CO2 and traces of other gases) remaining slurry. Biogas: cooking, heating, fuelling of vehicles and combined heath and power generation. Slurry: fertilizer for use in agriculture Anaerobic digestion is thus a feasible process in closed-loop systems “Anaerobic digestion is a biological process that takes place in absence of air. The process is endothermic which means that the process consumes heath and if thermophilic temperatures are to be reached an external heath source is needed. The organic material is broken down by microorganisms to the final products water, biogas (a mixture of methane, CO2 and traces of other gases) and a remaining slurry. Biogas can be used for cooking, heating, fuelling of vehicles and combined heath and power generation. The slurry from the biogas reactor is a valuable fertilizer for use in agriculture because all phosphorus and potassium and the majority of the nitrogen present in the influent is still present in the effluent. Anaerobic digestion is therefore a feasible process in closed-loop systems for recycling of resources from blackwater and fecal sludge to agriculture.” Source: (29) Source: (29)

“Small biogas digesters serving one household (as shown above) are increasingly popular especially in Asia, but also in other parts of the world. The main goal of the household digesters is to produce biogas and provide the family with energy. The basis input is animal manure from a small household livestock, but human excreta and other organic wastes can be used in addition. The digester is generally built subsurface for protection from temperature changes and to save space.” Source: (29)

Large-scale biogas digesters: common for treatment of agricultural waste or organic municipal waste. High gas yields of such digesters  combined electricity and heat production. Digester residues = as fertilizers. usually heated and use mechanical agitation of the digester content for optimised gas production mesophilic ( °C) or thermophilic (53°-55°C) Large-scale biogas digesters are common for treatment of agricultural waste or organic municipal waste. Domestic wastewater or excreta from on-site sanitation systems or decentralised wastewater collection systems can also be co-treated in such digesters. High gas yields of such digesters allow combined electricity and heat production. Digester residues are used as fertilizers. Large digesters are usually heated and use mechanical agitation of the digester content for optimised gas production. The digestion process can be mesophilic ( °C) or thermophilic (53°-55°C). Thermophilic digestion systems offer higher gas production, faster throughput and complete pathogen removal, but require more expensive technology and a higher degree of operation and monitoring. The residual liquid from thermophilic digesters can safely be used as fertilizer, whereas from mesophilic digesters it has to be sanitized separately, e.g. in a pasteurization unit or by maturation in a sludge drying bed (see below) (30). Large Scale Biogas Digestion Plant Source: (30)

In small biogas digesters, the process is operating at ambient or mesophilic and is difficult to control. Temperature and retention time therefore vary and sufficient pathogen reduction is difficult to achieve even at long retention times Pathogens Termophilic (53-55°C) Mesophilic (35-37°C) Ambient (8-25°C) fatality days Salmonella 100 % 1-2 7 44 Shigella 1 5 30 Polivirus - 9 Schistosoma ova <1 7-22 Hookworm 10 90 % Ascaris ova 2 98.8 % 36 53 % 100 In small biogas digesters, the process is operating at ambient or mesophilic and is difficult to control. Temperature and retention time therefore vary and sufficient pathogen reduction is difficult to achieve even at very long retention times (see graph below). Post-treatment like drying or thermophilic composting with organic material is advisable. Source: Zhang Wudi et al. (26)

Treatment: Drying and Humification
P. Jenssen

Faecal sludge from pit latrines and septic tanks as well as residues from ambient temperature or mesophilic anaerobic digestion generally require further treatment for hygienization Sludge drying and humification: drainage layer of gravel covered by a filter layer of sands. The humification bed is planted with wetland plants, normally common reed (Phragmites).” “Faecal sludge from pit latrines and septic tanks, as well as residues from ambient temperature or mesophilic anaerobic digestion generally require further treatment for hygienization and to render the end product more acceptable for handling. In principle the construction of both sludge drying and humification beds are the same, starting with a drainage layer of gravel covered by a filter layer of sands. The humification bed is planted with wetland plants normally common reed (Phragmites).” Source: (29)

P. Jenssen Traditional sludge drying bed: used for dewatering and drying of fecal sludge and anaerobic digester residue. Drying beds: simple sand and gravel filters batch loads of sludge are dewatered by percolation solid fraction remains on the filter surface and is dried by natural evaporation. reduces water content to 20-30%,  partial pathogen removal. Further treatment necessary Percolate contains pathogens! “A traditional sludge drying bed can be used for dewatering and drying of fecal sludge and anaerobic digester residue. Drying beds are simple sand and gravel filters, where batch loads of sludge are dewatered by percolation of the liquid fraction through the filter. The solid fraction remains on the filter surface and is dried by natural evaporation. Sludge drying reduces water content to 20-30%, which induces partial pathogen removal. However the dried sludge still may contain pathogens, particularly Helminth eggs, and should therefore be handled carefully and receive further treatment, e.g. composting or prolonged storage before use in agriculture. The percolate from dewatering will still contain pathogens, mainly bacteria and viruses and has to be further treated.” (28)

P. Jenssen Humification: process of sludge treatment in planted dewatering/drying beds sludge is loaded on the bed and dewatered by percolation in the filter and by evapotranspiration through the plants. Root system maintains permeability of the sludge layer. sludge is be added intermittently. Removal of sludge every years depending on design (stop 2 years before emptying) very well mineralized product, soil-like structure. Direct use in agriculture possible Percolate needs treatment “Humification describes the process of sludge treatment in planted dewatering/drying beds (see figure above) The sludge is loaded on the bed and dewatered by percolation in the filter and by evapotranspiration through the plants. The root system of the plants maintains the permeability of the sludge layer. The sludge is be added intermittently. Sludge has to be removed only once every years depending on design. It is normal to stop addition of sludge one to two years before emptying (while a parallel bed receives the sludge). The final product has is very well mineralized and has a soil-like structure. The long solids retention period and pathogen die-off and allows direct reuse of the solids in agriculture. Percolate quality considerably improves but may still require a polishing treatment.” (28)

Treatment: Additional Treatment Methods
P. Jenssen

Treatment: Wastewater-Fed Aquaculture
Wastewater-fed aquaculture (WFA) productive wastewater treatment, Ancient way to treat and recycle wastewater. constructed aquatic ecosystem with integrated food web  assimilation of dissolved nutrients into biomass. organic compounds consumed or mineralised, Purification of wastewater.  process must be controlled well in order to avoid disease transmission! Note: WFA is not going to be dealt with in detail here. For more information refer to the further reading part. “Wastewater-fed aquaculture (WFA) is a productive wastewater treatment, contrary to other methods of biological wastewater treatment, which are primarily based on degradation processes. Wastewater is reused instead of disposed of. A wastewater-fed aquaculture is an ancient but nevertheless innovative and successful way to treat and recycle wastewater. A constructed aquatic ecosystem, consisting of one or several water bodies with an integrated food web, is charged with nutrient rich wastewater. The central aim of the system is the assimilation of dissolved nutrients into biomass. Simultaneously organic compounds are either consumed or mineralised, and in consequence the wastewater gets purified. The constructed ecosystem reflects processes of the natural environment and is thus aesthetically pleasing. In contrast to conventional wastewater treatment plants, WFA puts strong emphasis on the quality of the synthesised biomass and produces a wide array of valuable goods and relatively small amounts of sludge. Wastewater-fed aquaculture therefore complies to several points of the ‘Bellagio Statement' concerning the environmental sanitation: In WFA 'waste' nutrients are respected as a resource and the economic opportunities of waste recovery and use are harnessed. It allows waste to be managed close to its source and wastewater to be recycled and added to the water budget. It offers vast potential of adaptation to any local situation. It can be optimized along several dimensions, allowing different degrees of intensity. · Wastewater-fed aquaculture can be applied in either decentralised or centralised systems of water purification. It can be extensive, (e.g. Calcutta Wetlands), but also intensified by a higher input of energy and technical elements into the system.” (27) However, care has to be taken in WFA systems that the used wastewater is treated adequately in order to prevent the spreading of diseases. J. Heeb

Treatment: Further Treatment Methods – Vermicomposting
Worms transform organic material in their digestive tracts Nutrients become plant available earthworms provide deep aeration for soils and prevent compaction. Eisenia Foetida Earthworms do not survive temperature above 38°C high moisture levels needed No acidic soils No mixing, tumbling or chopping of material Longer retention times than thermophilic composting to get safe product In the last 10 to 15 years, vermicomposting – using earthworms to hasten the breakdown of organic matter – has become popular. Worms transform organic material in their digestive tracts, so that their faecal matter, called ‘castings’, is rich in nutrients that are ready for plants. Equally important, by virtue of their ability to burrow deep and come to the surface often, earthworms provide deep aeration for soils and prevent compaction. Earthworms are not very happy at the high temperatures that can occur in composting (over 38°C), nor can they tolerate low moisture levels, highly acidic (low pH) environments, or being in materials that is often mixed, tumbled or chopped. Thus, they are not well suited for many of the small commercial household or garden composters or larger composting systems that aim at thermophilic conditions and where the compost is turned or tumbled. In order to kill pathogens vermicomposting needs much longer retention times than without adding new material than thermophilic composting. Three types of worms are commonly found in compost piles: red worms (lumbricus rubellus), brandling worms, or “red wigglers” (Eisenia foetida), and white worms (Enchytraeis). It's the red wigglers – sometimes called sewage worms – that are commonly used in larger-scale composting of organic wastes. Adapted from (34) Source: Adopted from (34)

Handling and transport of excreta and sludge
J. Heeb Manual handling: critical points from a health risk perspective. Protection measures when handling fresh and excavated material: Gloves Shoes  wash hands! Store material out of reach for people or animals! “Since many source separating systems are decentralised systems not relying on pipes, manual handling of recyclates is sometimes necessary. Though for most systems, only the handling of treated substances is necessary, the handling is still one of the most critical points from a health risk perspective. However, if proper protection measures are taken the risk is minimized. It is therefore important to use protection when handling the material and that excavated material is buried immediately or stored out of reach for people or animals until proper maturation times have been reached. In addition to protective clothing as gloves and boots normal hygiene and washing after the emptying operation is ended is important.“ Source: (29) Source: (29)

Different materials might need to be handled: Dry materials: (dehydration/composting toilets, dried sludge and compost. Sludge: septic and settling tanks, filters, anaerobic digesters, etc. (liquid) Contents from pit latrines: solid to liquid, often also containing solid waste. Different options are available: Manual handling through excavation or emptying using buckets, Mechanical emptying and transport, by vacuum trucks, etc. Pumping and piped transport of liquid sludge. Piped sludge transport is the safest way of transport but is only an option if transport distance is limited and pumps can be afforded and managed P. Jenssen A quick coupling at the property line for rapid and safe emptying of a blackwater holding tank by vacuum trucks. “Faeces and sludge need to be handled at various steps within a sanitation, treatment and reuse system. Handling and transport of faeces and sludge constitute a very critical point in a sanitation system, as people handling these materials may be exposed directly to pathogens. Materials that need to be handled may be very variable in nature, depending in their origin: Dry materials from dehydration toilets or composting toilets, dried sludge and compost. Sludge from septic and settling tanks, filters, anaerobic digesters, etc., generally of liquid or semi-liquid consistency. Contents from pit latrines with a consistency ranging from solid to liquid, often also containing solid waste. Different options are available for handling and transport of faeces and sludge. Manual handling through excavation or emptying using buckets, transport in buckets or simple carts Mechanical emptying and transport, by vacuum tankers, trucks, etc. Pumping and piped transport of liquid sludge. Piped sludge transport is the safest way of transport but is only an option if transport distance is limited and pumps can be afforded and managed.” Source: (29) Source: (29)

Source: ACTS Suction with a vacuum pump: classical technology for emptying of septic tanks, pits, direct contact of the workers with the sludge is significantly reduced  safest technique available. Tanks may be mounted on carts pulled by tractor or animals  smaller units possible Manual handling: Use of shovels and buckets great health risks Manual handling should be eliminated wherever it is possible. Source: (29) “The classical technology for emptying of septic tanks, pits, etc. is by suction with a vacuum pump. A hose is introduced in the tank or pit and the content is sucked out. The direct contact of the workers with the sludge is significantly reduced and is therefore the safest technique available. The pump is usually connected to a truck-mounted tank of variable capacity. In this way the truck can access the plot, empty the facility and then directly transport the sludge to the disposal or treatment site. Tanks may be mounted on carts pulled by tractor or animals, a system being considerably cheaper and technically equivalent to truck mounted systems. Smaller units or vacuum tugs, consisting of smaller tanks and motor or hand-driven vacuum pumps may be used in situations where very narrow access do not allow large vehicles. Manual handling normally comprises the use of shovels and buckets and may demand that the workers have to step into the pit, thus exposing themselves to great health risks. Manual handling should be eliminated wherever it is possible. However, manual handling will still be the final option when the use of vacuum pumps is excluded for certain reasons. Manual handling can be acceptable if the health risk to workers is minimized, i.e. when adequate protection measures by workers are used (gloves, masks, good hygiene). Most important is that workers be aware of the nature of the health risks to which they are exposed and that they know how to protect themselves. Training and targeted information may therefore be the most successful measures.” Source: (29) Truck with a vacuum pump for blackwater removal, Bangalore, India

Logistics of Sustainable Systems in Urban Areas
P. Jenssen Variety of systems needed for different: regions Legislation sociological aspects Budgets personal needs preferences. Reuse of nutrients easily practiced in rural areas  agriculture. Difficult in cities. Blackwater: contains majority of resources in domestic wastewater  of blackwater components, urine contains most nutrients Urine separation feasible in cities as well Source separation: Much smaller volume (facilitates transport) “It is unlikely that one single system can solve all future sewerage problems in our cities. Large investments have been made in conventional sewage systems which will be in operation for decades, but conventional systems will evolve as the principles sustainability and ecological engineering are communicated to engineers. Totally new systems as well as hybrid or combination systems will appear. A variety of systems are needed to meet the natural constraints of different regions, differing legislation, different sociological aspects, different budgets, personal needs, and preferences. Below are some key issues regarding the infrastructure of different systems discussed. The main focus is given to systems with decentralised collection and treatment. The reuse of nutrients from human excreta is quite easily practiced in rural areas, where the reclaimed resources can be used directly in agriculture. However, the situation is different for urban settings. Blackwater contains the majority of the resources in domestic wastewater. Of the blackwater components, it is the urine that contributes the greatest amount of nutrients. Systems with source separation require the use of toilets that use little or no water. These systems open a variety of new possibilities for wastewater treatment that also may include treatment of organic waste from other sources that the toilet (e.g. organic household waste).” Source: (7) Source: (7)

Source: (31) Source separation requires a change of sewage system infrastructure. The system logistics depends on toilet type, as the figure on the right shows:

P. Jenssen Source separating system: Dual or triple plumbing system needed However: smaller diameters Transport to agricultural production energy consuming (sustainable?) The more diluted, the less far can substances be transported by street Compost can thus be transported farthest, Blackwater: only short transport possible from a sustainability viewpoint  drawback has to be kept in mind “The use of a source separating system for wastewater treatment requires at least a dual plumbing system; one for blackwater and one for the greywater. If a urine separating toilet is used three handling lines may be needed – one for urine, one for the faecal matter and one for the greywater. However, the diameters of these individual pipes may be smaller than the pipes used now in conventional sewerage. The figure above shows that the blackwater, urine or composted faecal matter is collected and transported to agri- or silvicultural production. Transportation by truck is energy consuming and has to be taken into account in a sustainability analysis of a decentralized source separating wastewater treatment system in urban areas. One main question is how far is it feasible to truck the material. This is not an easy question to answer. The energy aspects of sewage treatment and fertilizer production are complex and a complete analysis is not available. One way to obtain data is to consider a truckload of blackwater, urine or compost toilet residue and look at the energy needed to produce an equivalent amount of mineral fertilizer. Generally, it can be said that the more diluted the substances are, the less far can excreta be transported. Compost can thus be transported farthest, while blackwater, which is usually diluted (as even vacuum toilets use about 0.5 to 1 Litre of water per flush), can only be transported over short distances in a sustainable way. This drawback has to be kept in mind when designing new sanitation systems for urban areas.” Source: (7) Source: (7)

END OF MODULE M3-1 seecon FOR FURTHER READINGS REFER TO M3-1 TUTORIAL
J. Heeb END OF MODULE M3-1 FOR FURTHER READINGS REFER TO M3-1 TUTORIAL Prof. Dr. Petter Jenssen, Department of Mathematical Sciences and Technology, Norwegian University of Life Sciences Dr. Johannes Heeb, International Ecological Engineering Society & seecon international Dr. Ken Gnanakan, ACTS Bangalore, India Katharina Conradin, seecon gmbh © 2006 Click here to go to the references part BACK TO THE MAIN MENU seecon International gmbh ACTS Agriculture -Crafts - Trades - Studies

++ References Alsén, K. W. & Jenssen, P. D. (2005): Ecological Sanitation – for mankind and nature. The Norwegian University of Life Sciences. WHO (1996): Cholera and other epidemic diarrhoeal diseases control. Fact sheets on environmental sanitation. World Health Organization, Geneva. – In: (29) WHO (2005) Nadkarni, M Fecal sludge use in high density urban environments. First International Dry Toilet Conference. University of Tampere, Tampere, Finland, August 20-23, – In: (29) WHO (2005) Berger, W Results in the use and practice of composting toilets in multi-storey houses in Bielefeld and Rostock, Germany. First International Dry Toilet Conference. University of Tampere, Tampere, Finland, August 20-23, – In: (29) WHO (2005) Mashauri, D., John, E., and Chaggu, E. Performance of ecological sanitation in Tanzania. First International Dry Toilet Conference. University of Tampere, Tampere, Finland, August 20-23, – In: (29) WHO (2005) Hanssen J.F., W.S. Warner, A. Paruch and P.D. Jenssen Sanitizing Partially-Composted Human Waste: Effect and Efficiency of a Secondary Reactor. paper presented on the 3rd International Ecological Sanitation Conference, Durban, 23 – 27 May – In: (29) WHO (2005) Jenssen, P.D., Greatorex, J.M, & Warner, W. S. (2004): Sustainable Wastewater Management in Urban Areas. = Kapitel 4. Kurs WH33, Konzeption Dezentralisierter Abwasserreinigung und Stoffstrommanagement. Universität Hannover. Jenssen, P.D. (2005): Ecological Sanitation – a technology assessment. PowerPoint-Presentation, 9th. International conference ”Ecological Sanitation” Mumbai India, November Holmqvist, A., Dalsgaard, A., Møller, J., 2003, Composting of faecal material - a hygienic evaluation, in “Proceedings of the 2nd International symposium on ecological sanitation”, Deutsche Gesellschaft für Technische Zusammenarbeit GTZ. – In: (29) WHO (2005) Møller, J., Dalsgaard, F. A., 2003, Reduction of faecal microbiological indicators in different compost toilets, in “Proceedings of the 2nd International symposium on ecological sanitation”, Deutsche Gesellschaft für Technische Zusammenarbeit GTZ – In: (29) WHO (2005) Strauss M and Blumenthal U J (1990). Human waste in agriculture and aquaculture; utilization practices and health perspectives. IRCWD, Dübendorf, Switzerland. – In: (29) WHO (2005) Del Porto D. & Carol Steinfeld (1998): The Composting Toilet System Book. A practical Guide to Choosing, Planning and Maintaining Composting Toilet Systems, an Alternative to Sewer and Septic Systems. Center for Ecological Pollution Prevention (CEPP), Concord, Massachusetts Peasey, A., 2000, Health aspects of dry sanitation with waste reuse, London School of Hygiene and Tropical Medicine – In: (29) WHO (2005) GTZ (2005): Technical Data Sheets for ecosan Components 02 Dehydration toilets. Draft Version. Eschborn, Germany. Available at: (Accessed ).

++ References Winblad, U. & A. Simpson-Hébert (2004): Ecological Sanitation. Revised and Enlarged Edition. Stockholm Environment Institute SEI. Jönsson H, Vinnerås B, Höglund C, Stenström T A, Dalhammar G and Kirchmann H (2000): Recycling source separated human urine. VA-Forsk Report , VAV AB, Stockholm, Sweden. – In: (29) WHO (2005) GTZ (2005): Technical Data Sheets for ecosan Components 01 Urine Separation toilets. Draft Version. Eschborn, Germany. Available at: (Accessed ). Jönsson, H. et al. (1997): Source- Separated Urine-Nutrient and Heavy Metal Content, Water Saving and Faecal Contamination. Water, Science and Technology 35(9) p Quoted in: GTZ (2005): Technical Data Sheets for ecosan Components 01 Urine Separation toilets. Draft Version. Eschborn, Germany. Johansson M., Jönsson H., Gruvberger C., Dalemo M. & Sonesson U Urine separation – closing the nutrient cycle (English version of report originally published in Swedish). Stockholm Water Company. Stockholm, Sweden. Available at: (Accessed ) Jenssen P.D ”Design and performance of ecological sanitation systems in Norway”, Paper at The First International Conference on Ecological Sanitation, Nanning, China. November 5-8. – In: (29) WHO (2005) Christine Werner, Florian Klingel, Ulrike Mosel, Sebastian Hass (2005): Vacuum Technology - collection and transport of sewage by means of low pressure. PP-Presentation held at the Pune Workshop Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ) GmbH ecological sanitation programme, Division 44 – environment and infrastructure. Vinnerås, B., Höglund, C., Jönsson, H. og Stenström, T.A Characterisation of sludge in urine separating sewerage systems. In: Klöve, B., Etnier, C., Jenssen, P., Maehlum, T. (Eds.). Proceedings of the 4th International Conference: Managing the Wastewater Resource – Ecological Engineering for Wastewater treatment. Ås, Norway. June 7-11, – In: Jenssen, P.D., Greatorex, J.M, & Warner, W. S. (2004): Sustainable Wastewater Management in Urban Areas. = Kapitel 4. Kurs WH33, Konzeption Dezentralisierter Abwasserreinigung und Stoffstrommanagement. Universität Hannover. Skjelhaugen O.J. (1999): Closed system for local reuse of blackwater and food waste, integrated with agriculture, Wat. Sci. Tech. no5 pp – In: (29) WHO (2005) Jenssen, P.D. and O.J. Skjelhaugen (1994): Local ecological solutions for wastewater and organic waste treatment - a total concept for optimum reclamation and recycling. Proc. Seventh International Symposium on Individual and Small Community Sewage systems, Atlanta, ASAE 18-94, pp – In: (29) WHO (2005) WELL, Technical Briefs, Using Human Excreta, Water and Environmental Health at London and Loughborough (WELL) (UK). – In: (29) WHO (2005) Zhang Wudi et al. (2001): Comprehensive utilization of human and animal wastes. Proceedings of the First International Conference on Ecological Sanitation in Nanning 2001,EcoSanRes, China. – In: (29) WHO (2005) Junge-Berberovic, R. (2001): Possibilities and limits of wastewater-fed aquaculture. University of Applied Sciences Waedenswil, Switzerland. GTZ Proceedings Nanning. Strauss, M.; Larmie, S.A.; Heinss, U. (1997) Treatment of sludges from on-site sanitation - Low-cost options. Wat. Sci. Tech No. 35, Vol. 6, pp , 1997. WHO (2005): Guidelines for the Safe Use of Wastewater, Greywater and Excreta. Chapter: Health Protection Measures (draft version December 2005)

++ References Mamit, J.D., P. Sawal, I. Larsen, T.H. Huong ”Integrating conventional and ecological sanitation in urban sanitation for the future”. Paper presented at the Third International Conference on Ecological Engineering, May 23-27, Durban South Africa. Jenssen, P.D. and Etnier C. (1997): Ecological engineering for wastewater and organic waste treatment in urban areas – an overview. – In: Mellitzer et.al. “Water saving strategies in Urban renewal“ Dietrich Reimer Verlag; Berlin pp Jenssen, P.,D., P.H. Heyerdahl, W.S. Warner and J. Greatorex. Local recycling of wastewater and organic waste - a step towards the zero emissionCommunity. In: T.D. Lekkas (ed.) Proc. 8th International Conference Environmental Science and Tecnology, Lemnos Island Greece, 8-10 september 2003. GTZ (2005): Technical Data Sheets for ecosan Components 04 Vacuum toilets. Draft Version. Eschborn, Germany. Available at: (Accessed ). George W. Dickerson (2001): Vermicomposting, Guide H-164. College of Agriculture and Home Economics, New Mexico State University.

++ Abbreviations ACTS Agriculture, Crafts, Trades, Studies
DM Dry Matter GTZ German Agency for Technical Cooperation OHW Organic Household Waste VIP-Latrine Ventilated Improved Pit Latrine

++ Glossary: Greywater
Greywater is only slightly polluted wastewaters from dishwashing, showers, laundry machines, water from sinks etc. Greywater makes up for the largest share of wastewater. Yellow water is either urine diluted with flushwater or pure urine. Urine contains most of the nutrients we excrete again, but only has a very low, if at all, pathogen count. However, we also excrete micro-pollutants or endocrine substances through urine. Brownwater refers to faeces mixed with (flushing) water, but no urine. Most of the pathogens are contained here. Blackwater is urine and faeces mixed with or without domestic wastewater from showers, washing machines, sinks etc. GREYWATER

++ Glossary: Temperature (extensive)
The ambient temperature for acceptable biological decomposition is 20°C to 45°C. Biological zero is 5°C, the temperature at which almost no microbial respiration occurs. At this temperature, most microbes cannot metabolise nutrients. In most composting systems, mesophilic (20°C-45°C) composting is at work. The heat generated by these microbes is usually lost through the vent stack, so composting toilets rarely reach termophilic rates (46°C to 71°C), which support thermophilic bacteria. This is the hot composting that takes place at the core of active yard waste composters. Achieving thermophilic composting would require either heating the composter – which would be expensive – or retaining the heat better by insulating or venting it less, which might mean odours and insufficient oxygen. In the highly contained environment of this kind of composter, it’s a hard balance to reach. Mouldering toilets support psychorophilic organisms, whose optimum temperature is above 5°C and below 20°C. These are predominately fungi and actinomycetes bacteria such as Streptomyces griseous […]. Mouldering systems are sized much larger than mesophilic composting systems to compensate for their reduced processing rate. Mouldering is usually the final phase after mesophilic and thermophilic processes have completed the early work of degrading sugars, fats and proteins. As the process cools, fungi and actinomycetous bacteria slowly digest the cellulose and lignin in plant matter, such as wood chips and toilet paper. Many manufactured compost toilets have heaters and thermostats to maintain an internal temperature of 32°C to 45°C to support the upper mesophilic composting range, while evaporating excess leachate […]. Generally, the rate of processing in a biochemical systems is directly proportional to the increase of temperature […]. The warmer the process, the more capacity in a composter. The cooler the process. The slower the rate – and more time or volume capacity may be needed for processing. A composter at or below 5°C will only accumulate excrement, toilet paper and additive until the temperature rises. Source: The Composting Toilet Book (12) TEMPERATURE Note that these definitions are not absolute. Other scientists use slightly higher or lower temperature ranges to refer to the above mentioned terms. These numbers should just give you a general idea of what the different temperature ranges refer to.

++ Glossary: Respiration
The metabolic process by which living organisms produce needed energy by the controlled oxidation of nutrients, such as carbohydrates. In this enzyme-controlled process, sequenced reactions slowly release the energy from nutrients. In most cases, oxygen, either molecular or bound in organic compounds, is utilized, and carbon dioxide (CO2), water (H2O) and energy are produced. In the case of the sugar, glucose, the following formula typifies the reaction: C6H12O6 + 6O2  6CO2 = 6H2O + Energy + Dissipated Heat (12). RESPIRATION

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