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Ecosan – some examples of multiple use of household wastewater. Adriaan Mels, Okke Braadbaart, Jules van Lier and Grietje Zeeman. Outline. SWITCH A bit of history on excreta reuse The constraints nowadays What are the recyclable components
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Ecosan – some examples of multiple use of household wastewater Adriaan Mels, Okke Braadbaart, Jules van Lier and Grietje Zeeman
Outline • SWITCH • A bit of history on excreta reuse • The constraints nowadays • What are the recyclable components • Examples (Jordan, Beijing, Lima, Sweden, Netherlands)
Multiple use of municipal wastewater Linear flow of conventional systems Circular flow of Ecological Sanitation
SWITCH – Ecological sanitation • Adoption and performance of established (demo) projects • Fate and removal of micro pollutants • Nutrient demand around a number of mega-cities • Innovative transport systems • Technical standards
Adoption and performance • Drivers (and barriers) • Performance (technology selection tool) • Public health and environmental protection • Resources (re)use • Technical performance • Financial performance • User aspects (acceptance, noise, smell, vermin, O&M) • Robustness
Feces and urine collection in Netherlands for agricultural use (1850-1950s)
Separate collection and use of flows Black water: handle with municipal organic waste Urine Urine: use as fertilizer Grey water: local treatment and use for toilet flush, laundry, car wash, irrigation
Distribution of nutrients Volume = 1.4 l per day per person on average
Distribution of wastewater flows Total 127 l / cap per day (The Netherlands) Grey water (2/3 of total wastewater) is relatively clean and can be treated locally
‘Available' phosphorus reserves (%) 100 2% growth 2.5% growth 80 3% growth 60 40 20 apatite 0 2000 2010 2020 2030 2040 2050 2060 2070 year Source: Driver et al. (2001) Global depletion of P reserves
World population not served with improved sanitation Source: Huber Technology
Examples of multiple use approaches • Urine re-use in agriculture (Sweden, Peru) • Grey water reuse for toilet flushing and landscaping (Beijing, Netherlands)
Urine sorting toilets Anno 2005 Anno 1900
Palsternackan Stockholm (constructed 1995):51 appartementen, 160 bewoners (urine separation)
Urine use in agriculture Urine is stored for 6 months (to remove remaining pathogens) and is directly used in agriculture
PERU OFFICIAL NAME: Republic of Peru CAPITAL: Lima AREA: 1,285,215 km2 COASTLINE: 2,414 km ESTIMATED 2005 POPULATION: 27,925,628 Residual water Latrine
AREA 1 - CENCA • A pilot project with 55 dry ecological toilets in two human settlements (slums) at the East of Lima, called Los Topacios of Nievería and Casa Huerta la Campiña of Cajamarquilla
AREA 1 - CENCA No-mix toilet Wetlands for grey water Composting chambers
AREA 2 - ALTERNATIVA • A pilot project in Ciudad Nuevo Pachacutec in Ventanilla with the construction of: • - 17 water reservoirs of 1500 m3 • - 837 public water taps • - 140 ecological toilets + green gardens + rabbits
AREA 2 - ALTERNATIVA No-mix toilet Fat Keeper Wetland Men urinal Green garden Rabbits
Separate collection and treatment of grey water Brown water Evt. urine Grey water 70 - 100 l /cap. per day Rain water
Grey water treatment and reuse in Drielanden, Groningen Constructed wetland Urban wasterscape
Beijing, a rapidly growing city Source: Bureau of Statistic of Beijing Municipality
… and a very water scarce city • Current water availability is < 300 m3 per capita per year • Severe overexploitation groundwater • The shortfall between water supply and demand is estimated to be around 1.8 billion cubic meters by 2010
Wastewater reuse planning Figure 1. Wastewater reuse planning for the Beijing central region (source: Jia et al., 2005)
Wastewater reuse planning • Current situation of wastewater reclamation systems in urban Beijing (note: this does not include wastewater reuse for agricultural irrigation and industrial reuse: • four centralized wastewater treatment plants for reclamation with total treatment capacity of 255,000 m3/day. • 300 - 400 decentralized wastewater reclamation systems with treatment capacity of 50,000 – 60,000 m3/day source: Water Saving Office,2006
‘Management regulation on the construction of wastewater reclamation facilities in Beijing’ (1987) • In this regulation the Beijing Municipal Government issued that: • hotels with construction areas exceeding 20,000 m2 and • all public buildings with construction areas exceeding 30,000 m2 • should build a decentralized reclamation facility. • As of 2001 also new residential areas exceeding 50,000 m2 fall under this regulation
Five cases presented (of 9 investigated) Beiluchun Residential Area Beijing Jiaotong University Beijing Normal University Xin Bei Wei Hotel BOBO Garden House Residential Area
Buffer tank Beijing Rainbow Hotel (max. 120 m3 / day)
Harvesting mixed wastewater Black water Grey water Rain water 150- 250 l / capita per day
Use of mixed wastewater in the Efteling, The Netherlands Centralised wastewater harvesting • Situated in relatively dry area • Restrictions on use of ground water • Uses approximately 550.000 m3/year municipal effluent • Aim: irrigation of golf courts and supply of water systems of the park
Case Study: Jordan Irrigated agriculture accounts for almost 65% of all current water use Irrigated agriculture water demand is expected to increase only slightly: 1998 863*106 m3 2020 890*106 m3 Generation of reclaimed wastewater is expected to increase drastically: 2001 73*106 m3 2020 265*106 m3 “It is mandatory that all treatment plant projects must include a fully designed and feasible reuse scheme”
Conveyance sewer (40 km) to Desert-WSP system As Samra WSP Conveyance pipeline (40 km) Amman (170.000 m3 sewage/day)
“Khirbet As Samra” Waste Water Stabilisation Ponds Actual situation: System loaded with 2 x design flow: HRT = 20 days • Effluent BOD: 150-200 mg/l • Little pathogen removal • Odour problems • High gas production in anaerobic ponds • Up to 15% of incoming wastewater evaporates • Concomitant salt increase Current problems
grit chamber screens Raw sewage Research: Implementing anaerobic treatment before ponds high-rate anaerobic treatment Existing stabilisation ponds Treated effluent Sludge sludge drying beds
Anaerobic treatment followed by stabilization ponds Cavalcanti et al. (2003) show that at an HRT of 10 days a removal of 99.99% of E-coli is achieved (i.e. compliance with WHO standards for unrestricted irrigation) Post treatment in pond systems, Bucaramanga, Colombia • Advantage: • Combines storage and treatment • Relatively cheap when land is available DMW CORPORATION, Japan
COD Removal: up to 80% BOD Removal: up to 85% SS Removal: up to 80% Pathogen Removal: - Coliforms: 70 - 90% - Helminth eggs: up to 100% Potential CH4 production in Amman (at 170.000 m3 sewage/day): 17,500 m3/day 2 – 2.5 MW Results two-stage pilot trials Middle East (Jordan): UASB Results “Sewage treatment”