Toilet design for rural areas and separated urine collection as a fertilizer source

Chia sẻ: Haivan Haivan | Ngày: | Loại File: PDF | Số trang:0

Thêm vào BST

Báo xấu

165
lượt xem 15
download

Download Vui lòng tải xuống để xem tài liệu đầy đủ

Rural water supply and sanitation is one of major programs for rural development applied not only in Vietnam but also in other developing countries. However, due to poor income and low knowledge conditions, the numbers of farmers achieve this are not so high.

Chủ đề:

Bình luận(0) Đăng nhập để gửi bình luận!

Lưu

Nội dung Text: Toilet design for rural areas and separated urine collection as a fertilizer source

SANSED WORKSHOP - 14-16 June, 2005, CanTho University, Vietnam --------------------------------------------------------------------------------------------------------------------------------- TOILET DESIGN FOR RURAL AREAS AND SEPARATED URINE COLLECTION AS A FERTILIZER SOURCE Le Anh Tuan1*, Joachchim Clemens2, Duong Van Ni3, Nguyen Thanh Phong1** 1 Department of Environmental and Water Resources Engineering, College of Technology, CanTho University, Campus II, Street 3/2, CanTho City, Vietnam. * E-mail: latuan@ctu.edu.vn, ** E-mail: nguyenthanhphong@ctu.edu.vn 2 Institute of Plant Nutrition, University of Boon, Karlrobert-Kreiten-St. 13, D-53115 Bonn, Germany. E-mail: a.clemens@uni-bonn.de 3 Mekong Delta Development Institute, CanTho University, Campus II, Street 3/2, CanTho City, Vietnam. E-mail: dvni@ctu.edu.vn --- oOo --- ABSTRACT Rural water supply and sanitation is one of major programs for rural development applied not only in Vietnam but also in other developing countries. However, due to poor income and low knowledge conditions, the numbers of farmers achieve this are not so high. Currently, there is a little documentation in Vietnamese concerning toilet design have been found in bookstores and libraries although this is a real need, special for rural areas. For this purpose, a rural toilet design manual was just written in the College of Technology (CoT), CanTho University (CTU). Many types and forms of rural latrine - toilets have been illustrated. Otherwise, some ways for human excreta and urine disposal collection and treatment have been introduced also. Urine contains a very high of the excremental nutrients. Separated urine collection for mineral fertilizer is researching in CTU. First, some initials experiments on odorless urine condensation are being done. A design of urinating blocks for pupils with separated urine collection and treatment system will be drawn. Then, a pilot one will be built in a selected rural school. From this pilot result, a further action plan on urine collection for mineral fertilizer production will be made. Key words: rural, sanitation, toilet design, urine collection, mineral fertilizer 1. INTRODUCTION Currently, the rapid increasing of population and pollution problem is gone concurrent, special in where almost a large numbers of the low-income people are living on. This even is happening in almost the developing countries. Vietnam in general and the Mekong river delta (MD) in particular, there is very low ratio of population served by adequate sanitation, especially in rural, peri-urban and poor urban areas (Anh, 2002). Not many of poor households have own sanitation toilet (Table 1 and table 2), almost are using very simple septic tanks or overhung toilets in ponds or rivers (figure 1). Table 1: Percentage of rural households owning latrines 1998 1999 2000 2001 2002 % households  20 # 30 32 34 37 (Source: L.V. Can, 2003) ------------------------------------------------------------------------------------------------------------------------------- Toilet designs for rural areas and 1 separated urine collection as a fertilizer source
SANSED WORKSHOP - 14-16 June, 2005, CanTho University, Vietnam --------------------------------------------------------------------------------------------------------------------------------- Table 2: Percentage of people accessing water supply and owning latrines in regions (2001) Per cent (%) Regions Accessing Owning water supply latrines Mountain area in the North 39 23 Red river delta 50 47 The Northern of central area 44 41 Coastal Central area 42 32 Highland area 36 24 The Eastern part of the South 53 46 The Mekong river delta 48 19 (Source: National Strategy for Rural Water Supply and Sanitation, 2003) Figure 1: Overhung toilet in pond in the MD Vietnamese people once have an idiom "Nhà sạch - Ruộng xanh" ("Clean house - Green field) considered as a rich and sustainable rural indicator. In 1999, the National Strategy for Rural Water Supply and Sanitation of Vietnamese Government has stated the goals: "Up to year 2010, about 70 per cent of households in rural areas have sanitation latrines and know how to apply personal hygienic" (Decision No. 104/2000/QÐ-TTg, dated 25 Aug. 2000, signed by the Prime Minister). So, for this purpose, there was a campaign namely "Building 3 sanitation works: water wells, bathrooms and toilets" have been deployed several years and got some successful in many places in the Northern and the Central regions of Vietnam. However, this expectation seems not to reach the general objectives in many rural areas of the Mekong River Delta because of economic difficulties, low income, the poor of building materials in the countryside and the lack of required information and skills of communities imply thinking nothing of sanitation needs in farmers and/or even poor hygiene awareness in rural development staff. Using toilet is one of actual human needs but it is really hardly to find some Vietnamese books and documents concerning sanitation facilities and hygienic human waste treatment in the libraries or bookstores, even simple ones. Otherwise, the ways for treating the excreta and urine as a source of mineral nutrient fertilizer have applied very little in the Southern of Vietnam. Humane urine has a high content of nitrogen, ------------------------------------------------------------------------------------------------------------------------------- Toilet designs for rural areas and 2 separated urine collection as a fertilizer source
SANSED WORKSHOP - 14-16 June, 2005, CanTho University, Vietnam --------------------------------------------------------------------------------------------------------------------------------- phosphorous and potassium (Simon, 2002). Thus, if one can separate the urine and find a suitable to have a mineral fertilizer and then distribute this fertilizer source back to the cultivated lands, we may achieve one of the goals for a sustainable eco-agricultural development. So, the main objectives of this report are to introduce:  A rural toilet design manual, its significance, contents and application.  An experimental concentration of nutrient in human urine. 2. RURAL TOILET DESIGN MANUAL Currently, the big gaps between the urban people and the rural people in Vietnam are their income opportunities, living standards, education and health conditions, and others. As a result, the farmers are limited to receive enough clean water supply and sanitation facilities as a social beneficiary. Furthermore, their living habits are directed toward the simple nature. It is difficult to break the thinking to defecate and urinate to the open fields in farmers and communities' daily life. In general speaking, there are some reasons listed that have limited the numbers of rural toilet building:  Low in-come;  High cost for a sanitation toilet;  Lack clean water;  Hardly to find good building materials;  Poor awareness in hygiene;  Not to like to defecate in a cramped toilet;  Consider human and animal excrement as a source for fish raising;  Not to be interested fully in local governments and rural development staff;  Very scare information and documents (books, guidebooks, manuals, ...) Awareness the uncontrolled and libertine sanitation situation in rural area was a population cause in water body, since mid-2003 to early-2005, CTU had accepted to develop a know-how reference document as a manual concerning rural toilet designs (Figure 2). The main goal of this work is to write a guidebook as a basic knowledge for farmers, rural development staff and local governments in fixative designing and building available low-cost toilets. The document emphasizes to reduce soil and water pollution, to use recycled human waste and to protect environment (Figure 3). It focuses the technical structures of the rural waterless and water toilets that can be applied in different rural regions and available financial investment capacity, not only to introduce some models in other countries but also to improve existing ones. Otherwise the community based toilet management is introduced. The structure of the manual, with five chapters totally, follows a logical sequence from the general pictures of rural toilet situation and problems in Vietnam, as reviewed in Chapter 1. Basic knowledge on rural toilet sanitation is encountered in Chapter 2. Coming to Chapter 3, some models of rural waterless toilets are introduced and analyzed their advantages and disadvantages. Similar, in Chapter 4 presents rural water toilet structures and also to compare their both sides of cost and benefit. Later, how to develop and manage toilets in community is discussed generally in Chapter 5. Finally, additional reading documents as reference are listed. An English - Vietnamese Toilet Dictionary is also added shortly at the end pages of the manual. ------------------------------------------------------------------------------------------------------------------------------- Toilet designs for rural areas and 3 separated urine collection as a fertilizer source
SANSED WORKSHOP - 14-16 June, 2005, CanTho University, Vietnam --------------------------------------------------------------------------------------------------------------------------------- Figure 2: Cover of rural toilet design manual TOILET Man Waterless Water To pond * COLLECTION Bucket Borehole Vault Septic tank Sludge latrine latrine tank toilet & TREATMENT TRANSFORT Excreta Collection Storage carrying cart vehicle pond Biogas To raise To To raise To fertilize tank earth worm keep fish field USE & REUSE To raise To raise poultry cattle Food Figure 3: Toilet classification, treatment and reuse system ------------------------------------------------------------------------------------------------------------------------------- Toilet designs for rural areas and 4 separated urine collection as a fertilizer source
SANSED WORKSHOP - 14-16 June, 2005, CanTho University, Vietnam --------------------------------------------------------------------------------------------------------------------------------- 3. SEPARATED URINE COLLECTION Urine seems to be a suitable mineral fertilizer if the urine is acidified (pH < 5) in order to reduce ammonia losses and plant damage (Simon, 2002). There were some data of the chemical feces and urine composition of the human and animal in Vietnam (Table 3) as well as average rate of excretion (Table 4). Table 3: Chemical composition of excreta and urine of the human and animal Content in % of weight Source of excretion P2O5 K2O N Pig dung 0,45 - 0,6 0,32 - 0,50 0,5 - 0,6 Pig urine 0,07 - 0,15 0,2 - 0,7 0,3 - 0,5 Domestic solid waste 0,60 0,60 0,60 Composted pig dung 0,25 0,49 0,48 Human faeces 0,50 0,37 1,00 Human urine 0,13 0,19 0,50 Human excreta and urine 0,20 - 0,4 0,2 - 0,3 0,5 - 0,8 (Source: Duc (1968), Tâm (1984) Table 4: Average daily human excretion Feces (grams) Urine (liters) Adult: Man 150 1.50 Woman 145 1.35 Child: Boy - 0.57 Girl - 0.35 (Source: Tuan, 1981) Many years before, in some places in Vietnam, human urine has been used for food plant cultivation. Separated urine from households was collected and stored in a small jar, farmers have put closed-urine naturally in one to six month and then mixed "composting urine" to water with an empirical ratio 1:5 or 1:10 before field fertilizer. According to EcoSanRes, fact sheet 6 stated: "The urine from one person will thus be enough to fertilize 300-400 m2 of crop per year and even up to 600 m2, if dosed to replace the phosphorus removed by the crop" (Source: http://www.ecosanres.org). A search from Sweden for volume reduction and concentration of nutrients in human urine has found that by freezing urine at a temperature of - 14C, approximately 80% of the nutrients can be concentrated in 25% of the original volume (Lind, 2001). However, this result can not be applied in Vietnam's weather condition. For a better understanding the way for urine collection, treatment and application rate in Vietnam, special in the MD, a proposal research has been established with the steps (figure 4):  Designing a suitable urine-diverting units likes a school urine collection blocks. Collected urine will be stored in designed tank.  Mixing urine with acid sulfuric for acidifying to reduce microbial contamination and ammonia emissions.  Drying the urine by solar and wind energy.  Collecting "drying urine" as mineral fertilizer and transporting it to the fields.  Testing applicable using urine fertilizer in some crops.  Recording all experimental analysis and farmers feedbacks. ------------------------------------------------------------------------------------------------------------------------------- Toilet designs for rural areas and 5 separated urine collection as a fertilizer source
SANSED WORKSHOP - 14-16 June, 2005, CanTho University, Vietnam --------------------------------------------------------------------------------------------------------------------------------- Wind Urine collection Solar energy Glass lid Urine fertilizer Fields Urine storage and treatment FOOD Eating Figure 4: Conceptual idea on nutrient cycle in urine collection, treatment and reuse Nitrogen in the urine is in the form of urea, CO(NH2)2, which can rapidly hydrolyze ammonium carbonate (Anderson, 2003) as reactions (1), (2) and (3): CO(NH2)2 + 3H2O  (NH4)2CO3 + H2O (1) (NH4)2CO3 + H2O  2NH4+ + HCO3- + OH- (2) NH4+  NH3 + H+ (3) It is foreseen that there are some advantages in using "dry urine fertilizer" research in the practice:  Urine is salvaged as a natural mineral fertilizer.  Urine is treated to become a solid and small volume fertilizer.  Urine fertilizer is lower risk of pathogen than composting one.  Urine fertilizer quality is higher and cheaper than chemical fertilizers  Urine fertilizer will contribute their role in environmental protection. However, some other disadvantages may be found:  Urine is hardly to collect, special in rural areas.  Urine may lead a bad smell if having a careless treatment.  Urine fertilizer production organization is not easy to persuade farmers, commercial investors and local government. ------------------------------------------------------------------------------------------------------------------------------- Toilet designs for rural areas and 6 separated urine collection as a fertilizer source
SANSED WORKSHOP - 14-16 June, 2005, CanTho University, Vietnam --------------------------------------------------------------------------------------------------------------------------------- 4. DISCUSSION It is necessary to distribute widely the know-how technology to the farmers. The aim of this research is to help rural communities some available low-cost technical documents. The rural toilet design manual has finished its final draft and being last edited. We need a financial support for publication. A study of separated urine collection and treatment is going on. It is an interesting research with full of promise in theory but there are some rocky application in practice as mentions above. Anyway, urine applicable for rural development has very useful and meaningful not in social economic but also in eco-environmental protection. 5. ACKNOWLEDEMENTS The authors would like to thank financial support from CTU through his science research fund for development the manual and Germany Government through the SANSED project for implementation the urine research. We would also like to acknowledge all the teaching and support staff of the Department of Environmental and Water Resources Engineering and HoaAn biodiversity experimental station for their spirit support and allowance to use the laboratories equipment and facilities for our on-going research. REFERENCES Anderson, A.; Strader,. R, Davidson, C. (2003). Airborne reduced nitrogen: ammonia emissions from agriculture and other sources. Environmental International 29 (2003). pp. 277-286. Available online at http://www.sciencedirect.com. Anh, N.V.; Ha, T.D.; Nhue, T.H.; Heinss, U.; Morel, A.; Moura, M.; Schertenleib, R., (2002). Decentralized wastewater treatment - new concept and technologies for Vietnamese conditions. IWA: 5th specialized conference on small water and wastewater treatment systems. Istanbul-Turky, 24-26 Sep. Can L.V. (2003). Rural domestic water supply and sanitation. Agriculture and Rural development Journal 2(2003). Vietnam. Lind, B.; Ban, Z.; Stefan, B. (2001). Volume reduction and concentration of nutrients in human urine. Ecological Engineering 16 (2001). pp. 561-566. Available online at http://www.elsevier.com/locate/ecoleng. Tuan, L.A. (2005). Rural toilet design manual. CanTho University, Vietnam. Tuan, V.A. & Tam, D.M. (1981). Human Feces, Urine and Their Utilization. Environmental Sanitation Information Center, Bangkok, Thailand Simons, J.; Gitta, S.; Joachim C. (2002). The use of separated urine as mineral fertilizer. Poster. Bonn University, Germany. Vietnam National program on Clean water and Rural sanitation (2002). Objectives of national strategies on clean water and rural sanitation to year 2020. Government official documents. Vietnam. WSP-EAP (2002). Selling sanitation in Vietnam. What works? Site reports and community data records from ADCOM, Water and Sanitation Program, East Asia and the Pacific. ------------------------------------------------------------------------------------------------------------------------------- Toilet designs for rural areas and 7 separated urine collection as a fertilizer source