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Ch. 1.2 Resources energy from waste via reuse to sustainability ? Where are the resources? What might be the problem to access them? Learning objective.

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Ch 1. Sustainable sanitation - a review Management & organisation Residents´ views & actions Physical arrangements including technology The challenge is.

Ch 1. Sustainable sanitation - a review Management & organisation Residents´ views & actions Physical arrangements including technology The challenge is.

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Presentation on theme: "Ch. 1.2 Resources energy from waste via reuse to sustainability ? Where are the resources? What might be the problem to access them? Learning objective."— Presentation transcript:

1 Ch. 1.2 Resources energy from waste via reuse to sustainability ? Where are the resources? What might be the problem to access them? Learning objective : To familiarise with a coordinated view on resources, and to understand the context and role of sanitation Jan-Olof Drangert, Linköping University, Sweden

2 Reflections on water and plant nutrients Water molecules cannot be manufactured or destroyed Water is renewable (sun- driven cycle) everywhere Water available in situ (rural, peri-urban) or imported (cities) Energy supplied by humans (rural) or electricity (urban) 70% of global water use is for crop production A balanced diet requires a loan of 1300m 3 /yr p person based on current practice. This is 70 times greater than the basic water need of 50 l per person per day. Phosphorus (P) cannot be manufactured or destroyed P is immobile and mined in only a few countries Food available in situ (rural) or mostly imported (cities) Energy supplied by humans and sun (rural) or fossil (urban) 90% of global rock P extrac- tion is for crop production A balanced diet results in depletion of 22.5 kg/yr of phosphate rock or 3.2 kg/yr of P per person based on current practices, of which 0.5 kg is found in the food. Jan-Olof Drangert, Linköping University, Sweden

3 agri- culture households excreta organics food fertilizer Losses on farm choice rain & irrigation water evapo transpi ration no choice manure Jan-Olof Drangert, Linköping University, Sweden Input to and output from the food chain loss

4 The water cycle – dynamics does the trick but, H 2 O is always on the move... Instant snap shot: Ice caps 2.7% Rivers % Lakes 0.007% Oceans 96.5% Clouds 0.001% Groundwater 0.7% Shortage of freshwater ! A dynamic perspective gives a better description: years years 8 days years 280 days Renewable rain gives in 2000 years as much water as is in the oceans!!! Jan-Olof Drangert, Linköping University, Sweden

5 Annual renewal and use of fresh water CountryH 2 O m 3 /person/ year km 3 /yr total in country Rivers from/to countries Portion being used Total use per year per person - by house- holds - by indu- stry - by agri- culture Sweden % 479 m 3 36% 55% 9% Holland % m 3 5% 61% 34% Saudi Ara % 255 m 3 45% 8% 47% Lebanon % 271 m 3 11% 4% 85% India % 612 m 3 3% 4% 93% Tanzania % 36 m 3 21% 5% 74% Kenya % 48 m 3 27% 11% 62% Egypt % m 3 7% 5% 88% USA % m 3 12% 46% 42% Chile % m 3 6% 5% 89% China % 462 m 3 6% 7% 87% Source: P. Gleick, 2003

6 Global scarcity of plant nutrients - a new driving factor for sanitation Phosphorus is a limited resource, and large untapped reserves will eventually only be found on sea shelves and as anthropogenic depositions in lake sediments. 95% of mined potash goes to the fertiliser industry and has no substitute. Exhausted in some 50 years. 60% of mined sulphur goes to fertilizer industry and has no substitute. Exhausted in some 20 years. Costly to recover these plant nutrients from lake sediments compared to trapping them directly at the source i.e. output from households and industries. Nitrogen can be manufactured from the N in the air, but this requires much energy (1 litre of oil to produce 1 kg of nitrogen). D. Cordell & J-O Drangert, Linköping University, Sweden

7 Phosphate Rock – Worldwide Estimates (thousands of metric tons) P scarcity is worse than oil scarcity because P CANNOT be substituted in food production Courtesy of Ian Caldwell, Stockholm Envrionment Institute, Sweden

8 Food, water and nutrient flows food H2OH2O 1.5 l 1.1 l transpiration & evaporation 0.9 l Urine: 1.5 l Faeces: 0.15 l Jan-Olof Drangert, Linköping University, Sweden + nutrients Virtual water 4 cu.m.

9 NUTRIENTS – and demography World Total 16 th - 21 st century Billion people Jan-Olof Drangert, Linköping University, Sweden 20 th century 9 rural urban 21 th century

10 Actual reuse of nutrients for urban agriculture & food security (in Swedish towns 1850 – 2000) 100% 50% waste pits + urine diversion + WC only WC + WWTP stop Jan-Olof Drangert, Linköping University, Sweden Proportion nutrients being reused Glass, tins, ceramics Heavy metals

11 Human resources: capacity to manage sanitation arrangements Utility Household Work hoursPaying fees Level of management User contribution pit latrine urine- diverting toilet flush toilet, WWTP, wetland Grease trap, Organic waste septic tank sewerage water supply, biogas drainage Jan-Olof Drangert, Linköping University, Sweden sewerage Organic waste biogas

12 Manpower blindness: driver of new responsibility sharing We tend to account only for what is done by governments and projects in water and sanitation What is done by residents and small entrepreneurs is rarely appreciated, if at all recognized (blindness) Yet, many urbanites survive thanks to such local initiatives Here, we pledge that both kinds of initiatives are needed to solve current sanitation problems Our pre-conceived views play a role Jan-Olof Drangert, Linköping University, Sweden


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