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Agricultural aspects of ecological sanitation

Agricultural aspects of ecological sanitation. Christine Werner, Patrick Bracken, Florian Klingel Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ) GmbH ecological sanitation programme, Division 44 – environment and infrastructure. Commissioned by:.

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Agricultural aspects of ecological sanitation

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  1. Agricultural aspects of ecological sanitation Christine Werner, Patrick Bracken, Florian Klingel Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ) GmbH ecological sanitation programme, Division 44 – environment and infrastructure Commissioned by: Water Resources Protection Workshop, 2-6 May, 2005, Selam Hotel, Asmara Workshop with the Water Resources Department, 07.05. - 08.05.2005, Asmara

  2. Increasing land degradation Desertification Desertification / soil erosion Important facts • 1/3 of the planet surface is covered by arid and semiarid zones Drylands in the Middle East cover 99% of the surface area. • Half the countries on earth lie partly or entirely in arid and semiarid zones. • Many millions of people have nowhere else to go except to live in arid zones • (UNEP, 1992) Source: http://pubs.usgs.gov/ Source:http://users.aber.ac.uk/ Workshop with the Water Resources Department, 07.05. - 08.05.2005, Asmara

  3. Key Elements of Biomass The limiting factors • Energy (Light) • Water (H²O) • Carbon Dioxide (CO2) • Nutrients • Minerals If one is missing, adding more of another will not help!! Macro nutrients: Nitrogen (N); Phosphorus (P); Potassium (K); Sulphur (S); Calcium (Ca); Magnesium (Mg) Micro nutrients: Boron (B) Copper (Cu) Iron (Fe) Chloride (Cl) Manganese (Mn) Molybdenum (Mo) Zinc (Zn) Workshop with the Water Resources Department, 07.05. - 08.05.2005, Asmara

  4. A simplified natural ecosystem In a natural ecosystem all minerals are part of a continuously ongoing cycle. Humus contains not yet mineralised organic matter. Workshop with the Water Resources Department, 07.05. - 08.05.2005, Asmara

  5. Introduction to ecosan Trend of fertilizer consumption (Saskatchewan Interactive, 2002) Workshop with the Water Resources Department, 07.05. - 08.05.2005, Asmara

  6. A simplified agro-eco ecosystem In an agricultural ecosystem, minerals and organic matter are exported from the soil when harvesting the products. What happens to them? Workshop with the Water Resources Department, 07.05. - 08.05.2005, Asmara

  7. For the consumer in = out An adult‘s body is barely growing. Most minerals we take up with our food will be found later in our excreta ! Workshop with the Water Resources Department, 07.05. - 08.05.2005, Asmara

  8. The nutrient content of faeces and urine Fertilising action: Urine - readily available on application Faeces - nutrients released slowly Workshop with the Water Resources Department, 07.05. - 08.05.2005, Asmara

  9. Nutrient Nutrients in Kg for crop production. Urine (500 l/year) Faeces (50 l/year) Total Required for 230 Kg de cereales Nitrogen 5,6 0,09 5,7 5,6 Phosphorous 0,4 0,19 0,6 0,7 Potassium 1,0 0,17 1,2 1,2 Total N + P + K 7,0 Kg (94 %) 0,45 Kg (6 %) 7,5 Kg (100%) 7,5 Kg Plantas verdes con follaje y no leguminosas Nitrogen Plantas flores y frutos Phosphorous Verduras de raíz comestible Potassium The nutrient content of faeces and urine Nutrients in urine N Urea P Phosphate K Ions Fuente: Wolfgast, 1993 Workshop with the Water Resources Department, 07.05. - 08.05.2005, Asmara

  10. Country Nitrogen kg/cap, yr Phosphorus kg/cap, yr Potassium kg/cap, yr China, total 4.0 0.6 1.8 Urine 3.5 0.4 1.3 Faeces 0.5 0.2 0.5 Haiti, total 2.1 0.3 1.2 Urine 1.9 0.2 0.9 Faeces 0.3 0.1 0.3 India, total 2.7 0.4 1.5 Urine 2.3 0.3 1.1 Faeces 0.3 0.1 0.4 South Africa, total 3.4 0.5 1.6 Urine 3.0 0.3 1.2 Faeces 0.4 0.2 0.4 Uganda, total 2.5 0.4 1.4 Urine 2.2 0.3 1.0 Faeces 0.3 0.1 0.4 Nutrient excretion The estimation of nutrients excretion per capita vary from country to country and even within the same region, according to food habits of people and the food itself Workshop with the Water Resources Department, 07.05. - 08.05.2005, Asmara

  11. Nutrients ecosan potential / example of India An adult excretes per year: ~ 4.55 kg N ~ 0.58 kg P (= 1.33 kg P2O5) ~ 1.27 kg K (1.53 kg K K2O) A family of 4 adults can produce the equivalent of around 30 kg NPK per year => Source: Esrey et al., 1998 => => No need to buy chemical fertilisers that are more and more expensive for farmers since fossil resources are diminishing One person can provide enough nutrients for:200 m2 to 400 m2 agricultural production area, depending on soil and plant type => Workshop with the Water Resources Department, 07.05. - 08.05.2005, Asmara

  12. Value of organic household waste Organic (kitchen) waste forms a valuable part of the overall household nutrient flow* of about: N: ~ 8% P: ~ 35% K: ~ 25% *1571 Analysis of the „Bundesgütegemeinschaft Kompost e.V.“ in 1996 Workshop with the Water Resources Department, 07.05. - 08.05.2005, Asmara

  13. Introduction to ecosan phosphate source: US Geological survey, 2003 • World demand for phosphate fertilizers continues to expand in relation to increased world population and food requirements. • For the period 2003-07, world phosphate consumption is forecasted to increase by 2.6% annually. • Within about 60 years, all reserved phosphate are expected to be mined. • Future conflicts on the access to phosphate are likely, due to the limited reserves and the concentration of significant minable resources in a very small number of countries. Workshop with the Water Resources Department, 07.05. - 08.05.2005, Asmara

  14. Recovery and reuse is necessary!! Minerals are very important for a successful agriculture. ? Fosile Thinking sustainable means thinking in the generation cycle. Organic It doesn't matter what we do today. Our grandsons and grand-daughters will have to use fertilizers from human resources (urine and faeces) anyway. Workshop with the Water Resources Department, 07.05. - 08.05.2005, Asmara

  15. Management of resources and quality Collection: • Product quality/ concentration • Strict separation of all non organic industrial wastes and waste water (toxics and heavy metals) • Awareness, support services, discharge control at household-level ! Out = In Treatment: • On Site / Off Site • Minimisation of waste and waste water • Guarantee for customer oriented product quality (sampling and control) • Maintenance of value Transport: • Distances from producer to fields (energy balance) • Concentration / purity of the product (costs) Marketing: • Acceptance by customer (informed choice) • Costs/benefit (market price) Workshop with the Water Resources Department, 07.05. - 08.05.2005, Asmara

  16. Reuse Bio waste, human faeces and urine can be re-used in agriculture and gardening under the following conditions: • Proper pre-treatment (storage, drying, composting, anaerobic fermentation, heating, filtration, irradiation with UV etc.) • Suitable „handling“ (observing all safety measures) • Depending on pre-treatment, the re-use should be limited to specific vegetables and field crops during specific vegetation periods • Regular sampling and hygiene control • Relation to the plant‘s needs in nutrients (no over-fertilization, ground water protection) Workshop with the Water Resources Department, 07.05. - 08.05.2005, Asmara

  17. Reuse Workshop with the Water Resources Department, 07.05. - 08.05.2005, Asmara

  18. Benefits of nutrients reuse: soil fertility Restoration of soil fertility: by reusing nutrients the soil is humus-rich and makes the difference in crops production faeces & urine urine none Source: Vinnerås, 2003 Workshop with the Water Resources Department, 07.05. - 08.05.2005, Asmara

  19. Benefits of nutrients reuse: soil fertility Spinach: Left - local soil Right - compost Green peppers: Left - excreta compost Mid - 1/2 compost, 1/2 soil Right - soil Lettuce: Left - local soil Right - excreta compost Source: Peter Morgan, 2004 Workshop with the Water Resources Department, 07.05. - 08.05.2005, Asmara

  20. Benefits of nutrients reuse: soil fertility Source: CREPA, 2004 Spinach: Left - local soil Right - urine (1 / 3) Sorghum: To : nothing T1 : with P and K T2 - T4 : P and K plus urine T5 : mineral fertiliser Source: Peter Morgan, 2004 Workshop with the Water Resources Department, 07.05. - 08.05.2005, Asmara

  21. Benefits of organic reuse: soil quality Improved soil quality: organic reuse (as compost) enhances the water - holding capacity, ameliorates the soil structure, the buffering capacity and by supporting the soil micro-organisms Source: Petter Jenssen After one week without water Workshop with the Water Resources Department, 07.05. - 08.05.2005, Asmara

  22. The fertilising effect of urine Results of a field trial using human urine as a fertiliser for leeks (Sweden) Workshop with the Water Resources Department, 07.05. - 08.05.2005, Asmara

  23. The fertilising effect of urine Yields (grams fresh weight) in plant trials with urine as a fertiliser to vegetables in Zimbabwe (Morgan, 2003) Workshop with the Water Resources Department, 07.05. - 08.05.2005, Asmara

  24. The fertilising effect of excreta compost Average yields (grams fresh weight) in plant trials comparing growing in poor topsoil only, with growing in a mixture consisting of 50% topsoil and 50% Fossa alterna compost (Morgan, 2003) Gains are less pronounced on better quality soils Workshop with the Water Resources Department, 07.05. - 08.05.2005, Asmara

  25. Agricultural use: urine Urine - How to apply ? • Urine is collected in tanks via pipes, from separating toilets • Urine is virtually sterile - usually contaminated when it contacts faeces Source: ecosan study in Havana • Treated by storage • Can be dilute for application (1/3) • Fertilising rules apply!!! Source: SUDEA Workshop with the Water Resources Department, 07.05. - 08.05.2005, Asmara

  26. Agricultural use: faeces • Techniques enabling the reuse of faeces in agriculture include: • Composting toilets • Dehydrating toilets • Anaerobic digestion with or no organic waste (biogas production) Direct injection of liquid fertiliser Dried faeces - „soil amelioration“ Composting with organic waste Urban agriculture Workshop with the Water Resources Department, 07.05. - 08.05.2005, Asmara

  27. Agricultural use: wastewater Nutrient recycling - epuvalisation (Senegal) Workshop with the Water Resources Department, 07.05. - 08.05.2005, Asmara

  28. Fishfarming with wastewater from ducks, poultry or pigs husbandry (Asia) Source: Nils de Pauw Workshop with the Water Resources Department, 07.05. - 08.05.2005, Asmara

  29. Hygienic risks of reuse • Urine - hygienic quality normally very high. Main risk is cross contamination by faeces • Faeces - risks much higher. Both primary and secondary treatment processes recommended (e.g. storage/composting followed by secondary composting • The HIV virus is very fragile and cannot be spread by treated (stored) “human residues” BUT poor water supply and poor sanitation conditions cause so called “opportunistic infections” as: Diarrhoea, Malaria, Cholera, Skin diseases etc. Workshop with the Water Resources Department, 07.05. - 08.05.2005, Asmara

  30. Survival of pathogens on crops and vegetables Workshop with the Water Resources Department, 07.05. - 08.05.2005, Asmara

  31. Survival of pathogens in the soil Workshop with the Water Resources Department, 07.05. - 08.05.2005, Asmara

  32. Category Use Person / Group exposed Nematodes[Eggs / kg] Faecal coliforms[number / 100 g] A Application to field crop (used for raw food) worker, consumer, public </= 1 </= 1000 B Application to field crop (for industrial use, feedstock, trees) worker </= 1 no suggested standard C Local application to field crop of cat. B, without contact to persons none not relevant not relevant Hygienic quality standards for reuse (WHO 1989) for wastewater Workshop with the Water Resources Department, 07.05. - 08.05.2005, Asmara

  33. Hygienic aspects Personal hygiene and handling care measures Gloves and shoes for work when handling ecosan products 33 Workshop with the Water Resources Department, 07.05. - 08.05.2005, Asmara Veranstaltung, Ort, Datum

  34. Risk minimisation Faeces and faecal sludge: • Pathogen removal in all treatment steps including: • Storage/treatment (weeks - 1 year) • Post treatment drying/composting, etc. (0,5-1 year) • Time period from application till harvest (0,1-0,5 y) • Compliance with recommended urine storage times (depending on storage temperature between 6 weeks (25oC) and 6 months (4oC) (pH) • Consideration of hormones and medical residues • Fresh use to trees Urine: • Separate treatment of industrial wastes / wastewater • Monitoring of dangerous substances Industrial wastes: Maintenance of ecosan systems: • Awareness raising and capacity building • Implementation of neighbourhood based services • Avoid misuse Workshop with the Water Resources Department, 07.05. - 08.05.2005, Asmara

  35. Balance of nutrient cycle In theory, one person can fertilise with his / her own ecosan recyclates an agricultural area, needed to feed him with vegetables, cereals and fruits. German law for fertilizer use / water shed protection Maximum N (Nitrate): 150 kg/(ha*a) Maximum P (Phosphorus): 25 kg/(ha*a) Extension area for urine and faeces application from one adult person: Workshop with the Water Resources Department, 07.05. - 08.05.2005, Asmara

  36. Recommendations for reuse • Excreta (urine and faeces): • Excreta should be handled and treated according to hygiene guidelines • Urine and faeces are complete fertilisers of high quality with low levels of contaminants such as heavy metals. The best fertilising effect is achieved if they are used in combination with each other, but not necessarily the same year on the same area • Faeces: • Both organic matter and ash, which are often added to the faeces, increase the buffering capacity and the pH of the soil, especially important on soils with low pH • Organic matter also improves the structure and the water-holding capacity of the soil • Faeces should be applied and mixed into the soil before cultivation starts • the application rate can be based on the current recommendation for the use • of phosphorous-based fertilisers. This gives a low application rate, and the improvement due to the added organic matter is hard to distinguish. However, faeces are often applied at much higher rates, at which the structure and water-holding capacity of the soil are also noticeably improved Workshop with the Water Resources Department, 07.05. - 08.05.2005, Asmara

  37. Recommendations for reuse • Urine: • Quick-acting nitrogen-rich complete fertiliser. Best used when applied prior to sowing, up until two-thirds of the period between sowing and harvest • Urine can be applied neat or diluted. However, the application rate should always be based on the desired nitrogen application • The recommended application rate and time for chemical nitrogen fertilisers (urea or ammonium if available) best starting point for developing local recommendations on application rate and time for urine. For translating such recommendations to urine, its concentration can be estimated at 3-7 g per litre • If no recommendations can be obtained, a rule of thumb is to apply the urine collected from one person during 24 hours to 1 square m of crop Workshop with the Water Resources Department, 07.05. - 08.05.2005, Asmara

  38. .... and ensuring health protection One person can provide enough nutrients for200 m2 to 400 m2 agricultural production area, depending on soil and plant type. Reuse often not a problem but: • Multi-barrier concept needed to secure hygienic safety in the reuse of human excreta and domestic wastewater: • Awareness raising and education on hygiene and reuse aspects • Effective treatment (primary treatment followed by secondary treatment if needed - storage, drying, composting, anaerobic digestion, heating, filtration, irradiation with UV etc.) • Suitable „handling“ (with security measures) • Limitation to specific vegetables and field crops, or to specific vegetation periods, depending on pre-treatment • the crops nutrient needs have to be respected (no over-fertilisation) Workshop with the Water Resources Department, 07.05. - 08.05.2005, Asmara

  39. For health protection hardware is not enough Esrey et al., 1991 Workshop with the Water Resources Department, 07.05. - 08.05.2005, Asmara

  40. The multiple barrier concept Workshop with the Water Resources Department, 07.05. - 08.05.2005, Asmara

  41. The pathogens to be stopped • Four groups of Pathogens: • Viruses: a strand of DNA in a protein coat, causing many types of illness • Bacteria: single-cell organism living in and around us. Some of them are helpful and some other cause diseases • Protozoa: large group of one-celled animal • Helminths: parasitic worms - toughest 41 Workshop with the Water Resources Department, 07.05. - 08.05.2005, Asmara Veranstaltung, Ort, Datum

  42. Infective dose of a pathogen (the dose required to create disease in a human host) • Bacteria: - medium to high dose required(>1 million) • Helminths, protozoa & viruses: - low dose required (< 100) • Note: 1g of faeces can contain millions oforganisms. Workshop with the Water Resources Department, 07.05. - 08.05.2005, Asmara

  43. Sanitation and hygiene • Good sanitation prevents excreta from entering the domestic environment and getting into water • Good hygiene prevents the transmission of microbes from the environment into the human body via hands • Adequate excreta disposal and safe hygiene practices together effectively prevent almost all gastro-intestinal infection. Workshop with the Water Resources Department, 07.05. - 08.05.2005, Asmara

  44. Water quality Fingers Hand washing Hand washing Fluids New Host Food Faeces Flies Water Quantity Fields The multiple barrier concept Proper treatment and management First Barrier Second Barrier Source: Wagner and Lanois, 1958 44 Workshop with the Water Resources Department, 07.05. - 08.05.2005, Asmara Veranstaltung, Ort, Datum

  45. Sanitising urine Time and Temperature Workshop with the Water Resources Department, 07.05. - 08.05.2005, Asmara

  46. Sanitising faeces Temperature pH Ammonia Dryness Solar radiation Competition Nutrients Oxygen Workshop with the Water Resources Department, 07.05. - 08.05.2005, Asmara

  47. Destructionofpathogens:Effect oftime andtemp. The safety zone Workshop with the Water Resources Department, 07.05. - 08.05.2005, Asmara

  48. Weigh the risks and benefits “In some cases the food supplied and the resulting improvement in nutrition may outweigh the potential health risks from this practice.” DRAFT GUIDELINES FOR THE SAFE USE OF EXCRETA AND GREYWATER Workshop with the Water Resources Department, 07.05. - 08.05.2005, Asmara

  49. Thanx For further information:www.gtz.de/ecosanorecosan@gtz.desubscribe to the ecosan-newsletter by sending a mail to :majordomo@mailserv.gtz.de(text of the mail: subscribe ecosan) Workshop with the Water Resources Department, 07.05. - 08.05.2005, Asmara

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