Lettinga Associates Foundation for Environmental Protection & Resource Conservation

Ecosan – some examples of multiple use of household wastewaterAdriaan 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

Otterpohl, 2000

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 performanceDrivers (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

Row of toilets in Ephesus, Turkey, from 1st Century

Feces and urine collection in Netherlands for agricultural use (1850-1950s)

Uit: De Prijs van Poep, NOVIB

Black water: handle with municipal organic waste

Urine

Grey water: local treatment and use for toilet flush, laundry, car wash, irrigation

Separate collection and use of flows

Urine: use as fertilizer

Distribution of nutrients

Nitrogen (13 g / cap.day)

80%

11%9%

UrineFecesGrey water

Phosphorous (2 g / cap.day)

53%26%

21%

Potassium (4 g / cap.day)

70%

20%

10%

Volume = 1.4 l per day per person on average

Distribution of wastewater flowsVolumes (l / cap. per day)

91.3

34.81.5

Grey water

Toilet flush

Black water (urine and feces)

Total 127 l / cap per day (The Netherlands)

Grey water (2/3 of total wastewater) is relatively clean and can be treated locally

Evolution of global water use

2000 2010 2020 2030 2040 2050 2060 20700

20

40

60

80

100

year

‘Available' phosphorus reserves (%)2% growth

2.5% growth

3% growth

apatite

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 1900 Anno 2005

Palsternackan Stockholm (constructed 1995):51 appartementen, 160 bewoners (urine separation)

Collection and storage system

Urine is stored for 6 months (to remove remaining pathogens) and is directly used in agriculture

Urine use in agriculture

PERUOFFICIAL NAME: Republic of Peru CAPITAL: Lima AREA: 1,285,215 km2 COASTLINE: 2,414 kmESTIMATED 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 - CENCANo-mix toilet

Composting chambers

Wetlands for grey water

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

Baño Ecológico

Sistema de tratamiento

Sistema de riego

AREA 2 - ALTERNATIVA

Fat Keeper

Wetland

No-mix toilet

Men urinal

Green garden

Rabbits

Why area matters for system performanceCENCA ALTERNATIVA

House property Inheritance Donation from government

Middle income (Soles/month) 340 530

NGO involvement after project finished Yes No

Inhabitants selected sanitation technology Yes No

Inhabitants designed their toilet Yes No

Inhabitants paid for the toilet Yes (only the 40%) No

Tap water Yes No

Toilets close to each other Yes No

Inhabitants manage the system Yes No

Users identified with the system Yes No

Brown water

Grey water

Evt. urine

Rain water70 - 100 l /cap. per day

Separate collection and treatment of grey water

Urban wasterscape

Constructed wetland

Grey water treatment and reuse in Drielanden, Groningen

Beijing, a rapidly growing city

02468

101214161820

1960 1970 1980 1990 2000 2010 2020 2030

Time

Popu

latio

n (in

mill

ions

)

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 planningCurrent 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)

BOBO Garden House Residential Area

Beijing Jiaotong University

Xin Bei Wei Hotel

Beiluchun Residential Area

Beijing Normal University

Item Beijing Jiaotong

University

Beiluchun Residential

area

Beijing Normal

University

Xin Bei Wei Hotel

BOBO Garden House

Residential area

Established in 1993 1999 2001 2002 2003 Influent source Grey

wastewater Mixed

wastewater Mixed

wastewater Grey

wastewater Mixed

wastewater Main treatment technology

Activated sludge

Aerated Ceramic

Filter Activated

sludge

Contact oxidation + disinfection

Contact oxidation + Activated

sludge Maximal reclamation capacity (m3/day) 200 640 720 120 1,200

Average reclamation (m3/day) 150 600 400 80 3001

Technologies and capacities

1 Another 700 m3 per day are treated and than discharged to the sewer system

Beijing Rainbow Hotel (max. 120 m3 / day)

Wastewater

Grid Bumper tankBiological

contact oxidation reactor

Erect sedimentation

tank

Machine filtration

tank

Reclaimed water storage tank

Disinfector

Flocculater adding

machine

Reclaimed water

Buffer tank

Black water Grey water

150- 250 l / capita per day

Harvesting mixed wastewater

Rain water

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

Use of mixed wastewater in the Efteling, The Netherlands

Centralised wastewater harvesting

Irrigated agriculture accounts for almost 65% of all current water use

Irrigated agriculture water demand is expected to increase only slightly:

Generation of reclaimed wastewater is expected to increase drastically:

1998 863*106 m3

2020 890*106 m3

2001 73*106 m3

2020 265*106 m3

Case Study: Jordan

“It is mandatory that all treatment plant projects must include a fully designed and feasible reuse scheme”

Amman (170.000 m3 sewage/day)

As Samra WSP

Conveyance sewer (40 km)to Desert-WSP system

Conveyance pipeline (40 km)

Overview 200 ha Pond System at “Khirbet As Samra” in Jordan

Effluent use for agricultural irrigation

“Khirbet As Samra” Waste Water Stabilisation Ponds

Actual situation: System loaded with 2 x design flow: HRT = 20 days

Current problems

- 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

screensgrit

chamber

Raw sewage

high-rateanaerobictreatment

Existing stabilisation

ponds

sludgedryingbeds

Sludge

Research: Implementing anaerobic treatment before ponds

Treated effluent

Anaerobic treatment followed by stabilization ponds

DMW CORPORATION, Japan

Post treatment in pond systems, Bucaramanga, Colombia

Advantage:Combines storage and treatmentRelatively cheap when land is available

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)

UASB Results “Sewage treatment”

Results two-stage pilot trials Middle East (Jordan):

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

Lettinga Associates Foundation for Environmental Protection & Resource Conservation

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