Utilization of Human Excreta Derived Resources for the Benefit of Urban Poor: An Integrated Approach toward Improved Sanitation

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prepared by Akira Sakai*, Qazi Azaduzzaman**, Musleh Uddin**, Hidenori Harada*** and Md. Nazmul Ahsan**** *University of Marketing and Distribution Sciences, 3-1 Gakuen-nishi-machi, Nishi-ku, Kobe, …

prepared by Akira Sakai*, Qazi Azaduzzaman**, Musleh Uddin**, Hidenori Harada*** and Md. Nazmul Ahsan**** *University of Marketing and Distribution Sciences, 3-1 Gakuen-nishi-machi, Nishi-ku, Kobe, 651-2188, Japan (E-mail: akira_sakai@red.umds.ac.jp) ** Japan Association of Drainage and Environment Bangladesh Office, House No.66 (Flat 4A), Road No.8, Block C, Niketon, Gulshan-1, D for Urban Environments in Asia, 25-28 May 2011, Manila, Philippines. organized by International Water Association (IWA).

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  • 1. Utilization of Human Excreta Derived Resources for the Benefit of Urban Poor: An Integrated Approach toward Improved Sanitation Akira Sakai*, Qazi Azaduzzaman**, Musleh Uddin**, Hidenori Harada*** and Md. Nazmul Ahsan**** *University of Marketing and Distribution Sciences, 3-1 Gakuen-nishi-machi, Nishi-ku, Kobe, 651-2188, Japan (E-mail: akira_sakai@red.umds.ac.jp) ** Japan Association of Drainage and Environment Bangladesh Office, House No.66 (Flat 4A), Road No.8, Block C, Niketon, Gulshan-1, Dhaka-1212, Bangladesh (E-mail: aazad013@yahoo.com, mmuparvez@yahoo.com) *** Graduate School of Global Environmental Studies, Kyoto University, Yoshida-honmachi. Sakyo-ku, 606-8501, Kyoto, Japan (E-mail: harada.hidenori.8v@kyoto-u.ac.jp) ****Fisheries & Marine Resource Technology Discipline, Khulna University, Khulna 9208, Bangladesh (E-mail: nazmul_ku@yahoo.com) Abstract In most of the urban poor settlements in developing countries, sanitation facilities are insufficient. Even if public toilets exist, it is usual the number of toilets is limited, some toilets are malfunctioned and defecated human excreta are seldom managed sanitarily. For example, there is no provision for sludge disposal despite toilets have septic tanks. Moreover, raw effluents from the septic tanks are directly contaminating water channels in urban areas. The authors implemented a baseline survey in Khulna city of Bangladesh to grasp the current situation of water use and sanitation and people’s concern on sanitation. Comparison to other areas of the city revealed that the most unhygienic environment prevails in the poor settlements with a high frequency of water borne diseases. The awareness level of residents on sanitation is low. Improving sanitation in urban poor settlements has been high on any development issues in Khulna city. Therefore, developing sanitation system with appropriate human excreta management is required urgently. The authors have developed a model for human excreta management in the urban poor settlements. Human excreta are treated as follows; urine can be used with organic compost to increase nutrient concentration whereas feces are decomposed to generate fuel gas through a biogas plant. The effects of the model have been verified through experiments. The results, up to now, reveal that installing the system, a community of poor settlement can expect to be provided benefit related to human excreta derived resources in addition to improved sanitation. Keywords Urban sanitation; resource recovery; human excreta managementINTRODUCTIONThe number of people living in the poor settlements in urban area of developing countries is increasingdrastically. In most of the urban poor settlements, the sanitation facilities are insufficient. Even if publictoilets exist, the number of the toilets is limited; moreover it is frequent those are broken, malfunctioned andfinally abandoned to use. Even though the toilets are used, defecated human excreta are seldom managedproperly. Up to now, various development projects have been carried out with little, if any, success inimproving urban sanitary situation as far as the sanitary human excreta management is concerned. Forexample, although toilets having septic tanks have installed, there is no provision for sludge disposal. Raweffluents from septic tanks in lack of proper maintenance are directly contaminating water channels insidethe city and rivers.A baseline survey result in Khulna city of Bangladesh implemented by the authors revealed that the mostunhygienic environment prevails in the poor settlements with a high frequency of water borne diseases.Furthermore, compared to other areas of the city, the residents have less awareness on sanitation. Improvingsanitation in urban poor settlements has been high on any development agenda in Khulna city.In this paper, based on the problems identified from the baseline survey result mentioned above, a model of
  • 2. human excreta management, which derives resources from human excreta, will be proposed for the urbanpoor settlements, considering social acceptance as well as technological and environmental sustainability.To make the model in practice, experiments have been done as a preliminary phase. Through the result ofthe experiments, application of the model to the urban poor settlements will be discussed.CURRENT SANITARY SITUATION OF URBAN POOR SETTLEMENTS IN KHULNA CITYPoor Settlements in Khulna CityKhulna city (Khulna City Cooperation; KCC hereinafter) is the third largest city in Bangladesh, located inthe southwest of the country. It covers 45.65 km2 and has nearly 1.5 million inhabitants. Khulna is animportant river port city and has become center for industrial development. There are 613 slums in KCCand the population living in slum areas is 227,500 (BCAS, 2005).The authors have implemented a baseline survey regarding water supply and sanitation in various areas ofKCC in January 2010 and 2011. Total samples are 700, in which slum and colony is defined as the urbanpoor settlements. Colony has been a residential area for the workers of factories, for example, but housesand infrastructure including sanitation facility is dilapidated with the times. Three slums and one colonyhave been selected as survey sites. The numbers of samples of slum and colony are 160 and 40,respectively.According to the results, types of the toilet in the poor settlements are septic tank (62%), pit latrine (17%)and other types including hanging latrine and direct discharge into drain (21%). Although the percentage ofseptic tank users is relatively high, it is easy to observe malfunctioning toilets regardless the toilet types. Fig1 shows the answer against the question “Did anybody of your family suffer from water borne diseasesduring last one year?” There is a remarkable difference in the occurrence of water borne disease betweenpoor settlements and other areas. As shown in Fig 2 and 3, people’s concern on sanitation is relatively lowin the poor settlements compared to other areas. On the other hand, although the conditions related to theliving environment are inferior, the willingness to improve their situation is low especially in slum residentsas shown Fig 4. Suffering from Water borne Disease Do you think your current defecation practise (Last 1 Year) pollute water? Slum Slum Colony Colony … Other  Other Areas KCC Total KCC Total 0% 20% 40% 60% 80% 100% 0% 20% 40% 60% 80% 100% Yes No Yes Middle  NoFig 1 Frequesncy of disease occurrence Fig 2 Concern on sanitation (1)
  • 3. Are you concerned about your domestic Willingness to Improve your Living Environment wastewater? Slum Slum Colony Colony Other Areas Other Areas KCC Total KCC Total 0% 20% 40% 60% 80% 100% 0% 20% 40% 60% 80% 100% Yes Middle  No I want to improve it Middle I dont careFig 3 Concern on sanitation (2) Fig 4 Willingness to improve environmentWater Flow Surrounding Slum AreasFig 5 shows water supply and wastewater flow diagram surrounding slums. These flow rates are calculatedbased on total slum population, unit water usage per person and ratio of discharge points of black and graywaters, which are obtained from the baseline survey result mentioned above. It is assumed that waterquality of canal or drain at downstream of slum areas are polluted, as septic tank is sole treatment facilitiesand most of them are not properly maintained, low frequency of sludge removal, for example. Waterquality test result at points of drain receiving discharge from some slums shows pollution of organic mattersand fecal coliform bacteria as shown Table 1.Fig 5 Flow diagram of water supply and wastewater surrounding slumsTable 1 Water quality test result at downstream of slum areas Coliform Fecal coliform DO EC BOD COD SS TDS NH4-N NO3-N PO4-P Bacteria Bacteria mg/L μs/cm mg/L mg/L mg/L mg/L mg/L mg/L mg/L MPN/100mL MPN/101mL 5 5BRAC slum 1.6 3450 166 270 4213 1720 4.4 6.3 0.44 >1.1x10 1.1x10 5 4Mashjid slum 0.7 3540 162 255 456 1770 4.3 6.1 0.39 >1.1x10 1.5x10 5 5Ashrat slum 1.3 6750 160 254 4712 3370 4.4 10.8 1.21 >1.1x10 1.1x10Problem IdentificationThe Baseline survey result reveals problems related to sanitation in urban slums in KCC. Lack ofappropriate sanitation, that is small number of toilets, insufficient maintenance of toilet and lack of humanexcreta management, affects health of the residents themselves and causes various impacts on environmentof surrounding residential areas and natural water resources. Another problem is low awareness level andlow willingness to improve their living environment among the residents, which might hamper the sanitaryimprovement and pollution control on water environment. To raise residents’ motivation, along withawareness program and proper information release, it is necessary to provide some incentive to improvesanitary situation.PROPOSAL OF SANITATION SYSTEM APPLIED FOR URBAN POOR SETTLEMENTSRequirements for Sanitation System Applied to the Urban Poor SettlementsGenerally speaking, hygienic situation without bad smell or fly is required for the toilets. In addition, in the
  • 4. context of sanitary human excreta management, utilization of human excreta derived resource is alsoattractive way and provides incentive to motivate slum residents.Working with ecological sanitation in the rural areas of Bangladesh, the authors found that thesocio-cultural concern of using human excreta as fertilizer can be successfully addressed through awarenessprogram and actual practice (Sakai, et al., 2007). Users of ecological sanitation have been brought thebenefit of using human excreta derived fertilizer for increasing crop productivity (Sakai, et al., 2010). It isone of key factors that users and rural communities accept ecological sanitation. In contrast, operation andmaintenance of ecological sanitation for public use in urban poor settlements appeared to be unacceptable,besides unlike the users in rural area, it is not readily apparent for urban residents to use resource bythemselves if fertile value of human excreta is utilized. Human excreta can be used as energy source also,and hence urban residents can also utilize human excreta derived resource. Therefore, along with using asenergy source, a technology involving on-site treatment of human excreta and off-site use of such resourcesgenerate impetus to motivate urban poor residents to install and manage sanitation facility properly.Appropriate management ensure a sustainable sanitation solution in the urban poor settlements.Proposal of Sanitation SystemThrough a series of consultation meetings and focus group discussions with different stakeholders, theauthors have developed a model for human excreta management in the urban poor settlements as depictedin Fig 1. As illustrated in the figure, urine will be used with organic compost, which is processed withvarious biodegradable solid wastes, to increase nutrient contents. On the other hand, fuel gas can begenerated from accumulated human feces by using a biogas plant. In addition to solid wastes, sludgematerials from biogas might also serve as a raw material for compost. The model proposes an on-sitecomposting facility thereby negating the transportation issue of raw urine and feces of large volumes foroff-site treatment or dumping. Biogas can be used in a community centre or supplied to some householdsnear the plant. Processed compost can be a product of organic fertilizer and income might be brought to theslum community by selling urine collected from urinal. This model aims at community based resourceutilization for the better livelihood. Urban poor settlement Public Toilets Community Urinal Defecation Center Bio-gas plant Fuel Septic Tank Solid Waste Compost Processing Soak pit (Adding Urine) Sludge Application Organic in Rural Area MattersFig 6 Model for sanitation improvement in the urban poor settlements
  • 5. SURVEY ON BIOGAS SANITATION SYSTEMDescription of the plantIn Bangladesh, biogas technology is commonly applying cattle excreta, but practices of applying humanexcreta are few. Research on biogas sanitation system is also limited (UNU-IAS, 2005). The plant surveyedis constructed at a dormitory of Shinomori Islamic School located in KCC. Students use the toiletconnected to a biogas plant. The number of the students is 175. The plant was constructed in 2006. Designretention time is 20 days. As the effluent from the biogas plant has high concentration of organic matter, theeffluent is treated by septic tank.Water quality and sludge test resultsWater quality parameters at some points of the plant have been analyzed including coliform bacteria andfecal coliform bacteria. As for sludge, nutrient content was analyzed. Parasites and protozoa test of sludgehas also done. Table 2 shows organic matters are being decomposed and the number of fecal coliformbacteria is reduced. Reduction of Kjeldahl nitrogen indicates nitrogen is being accumulated in sludge.Sludge test result shows relatively high concentration of nitrogen and phosphorus. From the test result ofparasites and protozoa, only Ascaris spp. (40 egg/g), Giardia spp. (200 cyst/g) is detected. The resultsindicate the biogas plant is capable to make excreta biologically stable, and septic tank is functioning toreduce organic concentration.Table 2 Water quality test result Coliform Fecal Coliform BOD5 COD EC TDS TSS TKN pH Bacteria Bacteria mg/L mg/L µs/cm mg/L mg/L mg/L MPN/100m MPN/100mL LInfluent 7.01 6780 15594 9480 3400 1245 2874 >1.2x104 >1.2x104Digester 6.43 1556 3180 5570 2680 369 780 >1.2x104 1.1x104Septic tank 6.46 778 1379 4150 2225 198 326 >1.2x104 7.5x102i fl 4Effluent 6.47 482 631 1385 2255 106 152 >1.2x10 2.1x102Table 3 Sludge test result Moisture TKN T-P K Sludge 85.63% 2.81 g/100g dry 1.42 g/100g dry 0.16 g/100g dryBiogas production and benefitBiogas volume was measured at the terminal point in the kitchen of the school, where biogas is used for cookingin the morning and noon time, for 3.5 hours totally. According to the school, about 70% of wooden fuel is savedby using biogas. In the experiment, water is heated by biogas using 20L pan. Calories provided by biogas weremeasured from the change of water temperature and volume. Gas volume was measured using measuringcylinder. The rate of calorie supply is constant for about 3 hours, then fall down rapidly. The experiment result issummarized in Table 4. The result corresponds to what hear from the school. From the calorie per biogasvolume and estimated gas volume, it is expected for every toilet user to get 450mL of hot water.The well maintained biogas plant provides benefit to the school. It is said a household buys 20BDT(Bangladesh Taka) wooden fuels for cooking purpose. Assuming the same percentage of wooden fuelsaving as the school, a household saves around 5,000BDT annually. Biologically stable sludge might beuseful as a source of nutrient rich organic fertilizer. Not only monetary benefit, through the reduction oforganic matters, water environment is expected to be improved.
  • 6. Table 4 Biogas generation relating informationNo. of users 175 personsGas flow under steady state 15.88 L/minCalorie supply under steady state 31.9 Kcal/minCH4 Concentration 48 % 3Calorie per gas volume 2008 Kcal/mTotal supplied calorie 5890 KcalEstimated gas volume 2.93 m3/dayCalorie loss (assuming 5500 Kcal/CH4m3) 24 %Calorie per user 33.7 KcalEquivalent to boiling water (25 - 100°C) 449 mLEFFECT OF URINE ON VEGETABLE YIELDOutline of the experimentUse of excess chemical fertilizer has brought various problems; low organic content in soils of farm is atypical example of its impact. Although organic fertilizer is recommended; sometimes nutrient contents arelow for sufficient yield. On the other hand, urine is nutrient rich and many of the ecological sanitation usershave obtained increased harvest in crops and vegetables by applying urine as fertilizer. The authors haveimplemented an experiment to know the effect of mixed use of urine and compost as a preliminary phase todevelop a technology to produce urine added compost.The experiment has been done at a farm which locates in the peri-urban area of Khulna city. Tomato wasselected as a crop to grow. Four treatments were set for the experiment as shown in the Table 5. For eachtreatment five plots are prepared, having area of 3.81 x 2.14 (8.16 m2) and 30 seedlings were planted foreach plot. Period of experiment is from November 2010 to March 2011. The soil test result of thecomposite sample from multiple points of the experiment plots indicates low content of organic carbon(1.1%) and nitrogen, medium content of phosphorus and high content of potassium. Nutrient content ofcompost and urine applied is shown in Table 6. The compost consists of poultry litter, bone meal, cow dung,water hyacinth, mustered oil cake, Azolla sp., saw dust and ash.Table 5 Treatments of the experiment Treatment fertilizing condition T1: control - T2: compost 6.5 kg/plot, applied 3 times T3: urine 165 L/plot, applied 3 times T4: urine + compost 165 L and 6.5kg/plot, applied 3 timesTable 6 Nutrient contents of applied urine and compost N P K urine 4710 mg/L 645 mg/L 1580 mg/L compost 17.5 mg/g 9 mg/g 6 mg/gFertile Effect of UrineFig 7 shows average yield of tomato among five plots for each treatment. Difference between T1 and T2does not show statistical significance. However, difference between T1 and T3 shows significance at 5%.Differences between T4 and other treatments show statistical significance at 1%. The result indicates bothorganic matter and nutrients are necessary for the satisfactory production in the low organic content farm.Comparing T2 and T4, assuming the increased yield is brought by urine application and price of tomato is10BDT/kg, 1L urine is equivalents to 2BDT. Compared to the previous survey (Takahashi, et al., 2009),this amount is bigger.
  • 7. 6 Yield of Tomato, kg/m2 5 4 3 2 1 0 Control Compost Urine Urine +  CompostFig 7 Differnce of tomato yield for each fertilizing conditionPROVISION OF IMPROVED SANITATION FOR THE URBAN POOR SETTLEMENTSThe sanitation system proposed in this paper aims at improved sanitation with appropriate human excretamanagement, deriving resource from human excreta to utilize it both on-site and off-site, which is intended to formincentive among residents in urban poor settlement. To make it in practice, a scheme shown in Fig 8 isrecommended. The scheme consists of following steps; 1) awareness raising on sanitation among the communitymembers, 2) problem identification under participation of the community, 3) forming willingness to improvesanitation, 4) selection of technical option and site selection of the necessary facilities, 5) establishing communitybased organization (CBO).Fig 7 Implementation scheme of the sanitation systemInstalled toilets and facilities are expected to be continuously maintained by CBO independently. Roles of CBO arenot only to conduct facility maintenance, but also to cover overall management of the sanitation system, whichconsist of followings;1) To determination cost sharing for contribution by the community2) To set-up management rule and make it familiarize among the community3) To make securing of financing for management: initial deposit, monthly charge and/or fee per usage
  • 8. 4) To maintain toilets and facilities5) To serve biogas to the community or common use at a community center near the biogas plant6) To manage selling or utilization of urine: invitation of compost factory near the settlement or establish such factory by themselves7) AccountingCONCLUSIONOutcomesBased on the baseline survey, the authors have discussed the necessity to improve sanitation of urban poorsettlements. As an incentive might be necessary to form willingness to improve current sanitary situation, and amodel was developed to utilize human excreta derived resources as shown Fig 1. To make the model practical,function of a biogas plant and the effect of urine when it is used with organic compost ought to be ascertainedpreliminarily. Based on the experiment results, following outcomes are obtained;1) Well-maintained biogas plant brings sanitary improvement and reduction of pollutants, in addition to deriving biogas from human excreta which is available as fuel.2) Applying organic compost and urine as fertilizer has brought increased yield of tomato.3) Implementation scheme and roles of community based organization are considered.Subjects for the next stepTo make the model feasible, various subjects including technical and social aspects still exists as follows;1) To develop a technology to produce urine mixed compost and verify its effect2) To confirm the stability of biogas generation based on a continuous survey of biogas plant function3) To develop measures to utilize sludge from biogas plant as resourcesAs a final target of the research, the authors intend to implement a case study based on actual slum area, toestimate overall benefit of the proposed sanitation system.ACKNOWLEDGEMENTThis study was implemented as a part of research named “Sanitation constraints classification andalternatives evaluation for Asian cities”, supported by the Japan Ministry of Environment, Grant #K22047,2008-2011. The authors would like to express gratitude to the following persons; Mr. Rahman, G. M. T. ofEnvironment Friendly Agricultural Development Foundation (EFADF) for his positiveinvolvement especially for set-up the experiment plot and providing organic compost. Mr. Md. Ibrahim, theschool master of Shinomori Islamic School, for offering various conveniences for the survey of the biogasplant. Mr. Md. Wahiduzzaman, an engineer of Local Government Engineering Department, Bangladesh,for his effective suggestion on biogas plant survey. Various survey practices have been done with dedicatedsupport of staffs of Khulna University and Japan Association of Drainage and Environment (JADE).REFERENCESBangladesh Centre for Advanced Studies (2005) Quantity and Quality Assessment of Khulna City Solid Waste for Electricity GenerationSakai A., et al. (2007) Challenges to Overcome the Problems Related with Sanitation in Rural Area of Bangladesh, Annual Conference, Bangladesh Regional Science Association, 1, 15pages (CD-ROM), Dhaka, Bangladesh.Sakai, A., Takahashi, K. and Azaduzzaman, Q. (2010) An Example of Benefit Estimation Related with Ecological Sanitation in Rural Areas of Bangladesh, International Water Association, Decentralized Wastewater Treatment Solutions in Developing Countries, Surabaya, Indonesia, 8 pages (CD-ROM)Takahashi, K., Sakai, A., Hosaka, H. and Takamura, S. (2009) An Effect and Benefit Evaluation of Eco-San Toilet Installment in Bangladesh Rural Area, Environmental and Sanitary Engineering Research, 23(1), 2-12.UNU-IAS (2005) Water and Sanitation in an Urban Poor Settlement: A Case Study of Bauniabad, Bangladesh