Presentation on theme: "Ecological Sanitation"— Presentation transcript:
1Ecological Sanitation [ Black Soil for the World‘s People ]
2 People contaminate the environment and are infected by it! The pathogen cycle People contaminate the environment and are infected by it!
3Some sanitation facts 1100 Million ( = 18 % of world population ) People without access to safe drinking water in the year 2000:1100 Million ( = 18 % of world population )People without access to sanitation facilities in the year 2000:2400 Million ( = 39 % of world population )Polluted water is estimated to affect the health of 1.2 billionpeople worldwide, and contributes to the death of 15 millionchildren each year.About 4 billion cases of diarrhoea occur each year:leading to 2.2 million deaths, predominantly among children,representing 15% of child deaths in developing countries.For the latest data see the latest "The state of the world's children“report from UNICEF, and UNDP‘s "Human Development Report“.
4...some more sanitation facts Worldwide, 5.3% of all deaths and 6.8% of all disabilities are caused by poor sanitation hygiene, and water.Some diseases that are caused (or supported) by unhygienic sanitation & faecal contaminated drinking water:Cholera, Typhoid Fevers, Diarrhoea, Dysentery,Infectious Hepatitis, Malaria, Polio, SchistosomiasisChlorine by-products, used to reduce the risk of infectious disease, are associated with a substantial portion of the cancer cases (bladder, rectal, colorectal and liver cancer) from drinking water supplies.900 million rural Chinese people excrete about 450 million tons of organic fertilizer each year - worth 2.6 Billion US$!The global human waste output (excrements) in the year 2000, is estimated to be 8.5 million tons each day ~ 49 million US$.
5Breaking the pathogen cycle To prevent illness pathogens must be blocked, so that humans are not exposed to them by inhalation and ingestion.Sanitation is the first and most effective point for blocking pathogens from faeces - when faeces are sanitized at the place of defecation almost no pathogens will enter the environment.
6The nutrient cycleThe fertilizing equivalent of excreta - nitrogen (N), phosphorus (P), potassium (K) - each of us produces, is nearly sufficient for a person to grow his own food!
7Nutrients in excrements The mineral plant nutrients per person and year (in kg) are:Nutrienturine(500 ltr. / year)faeces(50 ltr. / year)TotalRequired to grow 250 kg of cerealsNitrogen (N)4.00.54.55.6Phosphorus (P)0.40.20.60.7Potassium (K)0.90.31.2Urine:comprises 90% of the volume of human wasteit also contains about 80% all the mineral plant nutirents (N, P, K)Faeces:contain most of the carbonaceous (C) organic matter in our excrementscarbon increases the water holding capacity and nurtures healthy soilorganic matter serves as a soil conditioner and humus replenisheran asset not shared by chemical fertilizers!
8Closing the nutrient cycle Urine:is a good natural mineral (N, P, K) fertilizercontains only few pathogens and heavy metals – thus urine is a clean fertilizermixed with water (5–10 litre water / 1 litre urine) it can be used for crop irrigationFaeces:contain less minerals (N, P, K) than urinecontain the most carbon (C) in our excrementscontain a lot of pathogensthey must be sanitized prior to usagesanitized faeces can be safely composted together with other garden & kitchen organic wastesapplying the resulting compost to the soil restores the soil’s humus layer
9What is ecological sanitation? The flushing toilet system:VSThe ecological toilet system:Breaks the pathogen cycle by flushing away excrements.Breaks pathogen cycle by storing and sanitizing excrements.Needs a lot of water to flush away faeces and urine.Conserves water: uses either minimal water or even better: no water at all!Excrements, flushing water, household greywaters and indus-trial wastewaters are mixed.Excrements are processed near to the point of ‚production‘ without industrial contaminants.The output of modern wastewater treatment plant cannot be safely used as agricultural fertilizer – their effluents even contaminate rivers and the sea.Sanitized and co-composted faeces enrich soil‘s humus layer and nutrients in urine are returned to the soil as fertilizer – nothing is contaminated.
10What about the pit latrine? 2.8 billion people use them – pit latrines have several disadvantages:They cannot be used in areas with impenetrable ground, or with high water tables, or where flooding is a problem, or in densely populated areas where space is limited - even a deep hole will fill after some years of operation, so the pit latrine has to be relocated, causing space problems in small urban yards.Risk of groundwater contamination, threatening the drinking water:Increased nitrate levels in groundwater are caused by leakage from pits.Pit latrines often collapse during the rains, by groundwater entering the pit – latrines get waterlogged due to high water tables.Households with family wells in their yards have to keep their latrines at a safe distance from the water point (at least 10m, rather more).Often pit latrines are disdained because of smells and flies - especially during the rainy season:Certain disease vectors breed in humid pits - flies and mosquitoes like the humid environments of the latrines.These vectors are spreading pathogens and cause diseases like Malaria!
11Eco-San benefits (1) EcoSan tries to do both: Break the pathogen cycle -> no contact with unsanitized faecesClose the nutrient cycle -> reuse urine & faeces as fertilizer & soil conditionerTherefore it has a double effect on people’s health by:reducing diseaseimproving thenutrient intake
12Eco-San benefits (2)Safely recovering, and reusing human wastes as soil conditioner & fertilizer offers several benefits, including:reduces effluents to receiving bodies - rivers, lakes, the searetains valuable resources – instead of wasting themreduces the amount of chemical fertilizers imported for food production - reducing the dependence on chemical fertilizers, and saving money for schools, hospitals, etc.increases household food security - everybody surely can afford this fertilizer for his own gardening!creates jobs - in collection / composting systems / urban agricultureimproves living conditions – safe, fly-free, pleasant smelling & cheap toilet for everybodyhealthier children – can learn more and better and are happier!healthier people – can work better and earn more and are also happier!
13Eco-San benefits (3)While being attractive all over the world, especially developing countries can benefit from Eco-San:In combination, improved sanitation and higher nutritional status could significantly improve public health in developing countries.The higher temperature in many of the developing regions and the more concentrated urine, obtained from toilets or latrines that do not use flushwater, increase the pathogen inactivation rate. The low risks for transmission of infections through urine support the implementation of urine separation.In southern tropical climates, composting toilets or dry sanitation systems and combinations with reed bed filters may be more feasible and efficient.Combined composting toilets and filter systems may be appropriate for countries where sanitary ablution (anal cleansing with water as opposed to paper usage) is practised.
14Non-Eco-San problemsFailure to close the nutrient cycle has resulted in:1.) reduction of the soil’s humus layer (loss of soil fertility)(need for more watering)(increased risk of flooding!)2.) increased use of pesticides (healthy soil has been destroyed)3.) production and use of artificial fertilizers (since World War I)4.) nutrient and Chlor (Cl) overload (loss of biodiversity)in coastal and marine waters (toxic algae blooms)(fish & coral dying)
15Sanitizing urineSanitizing urine is not necessarily required, since urine from healthy people is also healthy:In a healthy individual the urine is sterile in the bladder.Some people drink their morning urine as a preemptive health caremeasure (to be more resistant against diseases).However, in areas where diseases like bilharzia, typhus, cholera, hepatitis A & B, tuberculosis or HIV/AIDS are endemic, urine should be sanitized prior to usage!Sanitizing urine by storing it in tanks:nitrogen in stored urine converts to ammonia, and the pH rises to about 9a low dilution with water should be sought – this will help to kill pathogenstemperatures should tend toward a warmer environment (20°C or more)Necessary storage time (at 20°C):6 months, when cross-contaminated with faeces1 month for clean urine (no faecal contaminations)
16Sanitizing faeces Here are 4 approaches to sanitizing faeces: Dehydration (desiccation):Dehydration to below 5 % of solids - in dry warm climate achievable within 4 months - will lead to complete inactivation of all worm eggs (also Ascaris eggs, which are the most resistant pathogens).Pasteurisation:70°C for one hour will kill as good as all pathogens.Aerobic composting:When composting the digesting aerobe bacteria will create high temperatures °C kills pathogens within days. Temperatures around 55-65°C kill all types of pathogens (except bacterial spores) within hours.Anaerobic digestion:Takes longer than composting and produces unpleasant smells (SOH4).
17Composting (1) The 6 composting essentials are: 1. Organic matter: ( carbon (C) and nitrogen (N) )Carbon is energy food for microorganisms.Nitrogen provides protein needed by the microorganisms to break down carbon.2. Microorganisms:The microorganisms produce heat and transform organic matter into compost.Good sources of microorganisms are soil and finished compost.3. Air:Composting bacteria are aerobic, which means they need air and cannot live in water,so air is necessary because they need a lot of oxygen (O2) to do their job.4. Water:Water is needed in a compost pile to keep the pile moist, but not wet.5. Temperature:When the ground is frozen the bacteria are inactive – temperatures above 20°C are nice.6. Time:If the previous 5 are present, compost is generated - whether within a month or a year.
18All composted biological material becomes humus. Composting (2)The C-N ratio:Since most of the job of composting is done by microorganisms the compost pile has to offer them a balanced diet of carbon (C) and nitrogen (N) to be attractive for them.Unfortunately the C-N ratio of our faeces and urine is not a good diet!Carbonaceous organic matter must be added to the compost pile, such as:wood shavings, grain husks, straw, ashes, soil, paper, …Earthworms:Vermiculture - adding earthworms for composting - is a very satisfactory method for obtaining a stable compost of high quality, with nutrients readily available for plant assimilation.Humus:During composting, the volume of the material is reduced by about 90% - the remaining 10% is humus, filled with the minerals that were withdrawn from the soil where the food was grown.All composted biological material becomes humus.
19Arbor Loo - composting toilet The Arbor Loo is a simple composting toilet with a portable slab,pedestal and superstructure over a shallow pit:maximum 1 meter in depthpit can be unlined, or with a protec-tive ring beam securing the pit headand raising the latrine slightly aboveground level.Wood ash and soil are added after eachuse to reduce fly breeding and odour.Layers of organic matter, such as leaves,can be added as well to assist in the de-composition process.When the pit is about 70% full:the slab and superstructure are removedand mounted over a new shallow pit.The filled and topped pit is then watereddown.On the following day a young tree is planted and again well watered.
20Double vault composting toilet Both urine and faeces accumulate in the shallow pit together withwood ash, soil and organic plant matter, which is used coverexcrements after defecation.When the first pit is nearly full:Slab and structure are moved to the second pitthe contents of the used chamber are coveredwith topsoil between 15 and 30 cm deep andleft to decomposeWhen the second pit is nearly full:the mature contents of the first pit are removedthey can be easily removed, without any offensivesmells – else decomposition is not totally finishedthey should look, feel and smell like rich compost
21Composting toilet with reed bed filter Reed bed filters are used to treat urine and greywater(‘greywater’ = wash water, from dish washing, laundry, shower etc.)The urine is drained from the toilet through a small tube to the exterior ofthe residence or latrine housing and piped together with the other waste-water into a shallow evapo-transpiration bed:The filter bed is filled with coarse sandIt has its own containing walls to prevent seepage (maybe with a thick plastic sheet at the bottom)Reed and if also desired flowers, shrubs and even fruit trees and coconut palms can be planted on the filter bed1 m2 of reed bed filter surface area is required per toilet userThe reed bed filter assimilates and evapo-transpires the effluent as itflows through the subsurface root system where impurities are removedby combining microbial, chemical and physical processes.
22Bucket latrineThe bucket holds excreta (faeces & urine) and added covering materialsit must be emptied every 1–3 days, preferrably every day.The bucket is made of rubber, enamel, galvanized metal, or lacquered woodit is placed under the slab, in the compartment created by the platformalso more simple constructions are possibleA laborer replaces the bucket with a clean one, empties the excreta into a larger container, and takes it to a composting site:Water must be available so the laborer can washthe containers and buckets.Composting can be done with no odour, flies ordisease.The compost is then used to fertilize crops.
23Biogas generationModern biogas technology constitutes a widely disseminated branch of technology with a history of over 30 years. The technology is efficient, well demonstrated and provides a cost-effective method of disposing organic wastes and producing fuel and fertilizers.Anaerobic bacteria degrade organic materials in the absence of oxygen. Methane and CO2 are produced. The methane component can be used as an alternative energy source.A reduction of total bio-solids volume of up to % can be realized. The final waste sludge is biologically stable and can serve as a rich humus for agriculture.The excreta of 25 people produce an average of about 1 m³ of biogas per day (40 l per person and day), representing the approximate cooking energy demand of one household.In institutions with 500 or more attendants (schools, prisons, religious centres, public facilities like markets) the produced biogas may supply sufficient energy for a canteen.Anaerobic treatment processes are suitable in tropical conditions because anaerobic treatment functions well in temperatures exceeding 20ºC.
24Some books The Composting Toilet System Book 235 pagesApril 1999ISBN:CEPP (Center for Ecological Pollution Prevention)The Humanure Handbook: A Guide toComposting Human Manure.302 pagesJuli 1999ISBN:2.nd edition - Jenkins Publishing (PA)
25Some organizationsSANDEC (Sanitation in Dev. Countries department of EAWAG (Swiss))SIDA (Swedish International Development Assistance)WSP (UNDP & World Bank: Water and Sanitation Programme)WSSCC (Water Supply and Sanitation Collaborative Council)IETC (UNEP Intl. Environmental Technology Centre (Japan))WEDC (Water Engineering and Development Centre (UK))CAWST (Centre for Affordable Water and Sanitation Technology (Canada))
26...some more organizations CEPP (Centre for Ecological Pollution Prevention)IRC (International Water and Sanitation Centre (Netherlands))IDRC (International Development Research Center (Canada))GARNET (Global Applied Research Network in Water Supply and San. (UK))AIT (Asian Institute of Technology (Thailand))Sanitation ConnectionEcological Engineering Group
27Some webpagesEcological Sanitation – an introduction by Steven A. EsreyThe Water Page – Ecological SanitationNews on the „2003 World Toilet Summit“ in Taipei (Taiwan)SSHE (IRC & UNICEF) news from Aug. 2002
28(from the 1st International Conference on Ecological Sanitation 2001) ...however, application of this revolutionary approach, and understanding of its implications for public health, agricultural gain, economic benefits, and institutional requirements - especially in modern urban settings - are still in their infancy...(from the 1st International Conference on Ecological Sanitation 2001)THE END...OR THE BEGINNING?