4.5 Greywater is man-made– an untapped water and nutrient resource

constructedwetland, gardening,

wastewater pond, biol.treatment, membrane-

technology

Greywater (shower, washing,

cleaning, etc.)

irrigation,groundwater recharge ordirect reuse

Learning objective:

the role of households in

tackling environmental

and resource challenges

Challenges and possibilities

Greywater represents environmental challenges:

- Unpleasant odours- Health hazard (pathogens and toxic compounds)- Soil erosion- Pollution of surface water and groundwater- Mosquito breeding

Benefits of using treated greywater and sludge:

+ Reduces water shortage+ Reduces environmental degradation, eutrophication and health hazards+ Reclaims otherwise wasted nutrients+ Alleviates food shortages and poverty+ Protects the quality of groundwater

Courtesy of Nicola Rodda University of KwaZulu Natal, Durban

UrbanwasteUrbanwaste

Treat-ment

Lowerquality

Drinkingwater

Urban

Stormwater

Surface &ground water

Activ-ities

Solidwaste

Urine

Greywater

Blackwater

Wastewater

Faeces

Compost

Compost &hygienization

Hygienization& concentration

Hygienizationmembranebiological

Wetlandaquacult

Sludgefractionationbiologicaltreatment

Horticulture

Agriculture

Forestry

Aquaculture

Industry

HouseholdSludge

Rain

Urban horizontal water and nutrient flows

Jan-Olof Drangert, Linköping University, Sweden

Urban unintended vertical flows of contamination

Landfill

Groundwater (saturated aquifer)

Sludge bed

Soil layer with organic material, clays and charged particles

IrrigationSeptic tank

Petrol station SewersPit

latrines

Jan-Olof Drangert, Linköping University, Sweden

 Water volumes (supply & disposal)

Shallow wellsDeeper wells

Periurban wells

Importedwater

Effect on

quantity: None Falling grw-level Over extraction Excess infiltration

Effect on

quality:        None Growing pollution Excessive pollution 

The effects of urbanisation on groundwater utilisation, quantity and quality

Courtesy of G. Jacks, Royal Institute of Technology, Stockholm

Settlement size

time

All groundwater under cities is polluted

Source: Powell et al., 2003

Wastewater = clean water + what has been added

Content in different fractions Component Faeces Urine Greywater

Impact (potential)

Means of control

Water lit/person/day flush included

4-10 (WC) 0 (no flush)

20-40 (WC) 0 (no flush)

80-200 - water scarcity - heat loss - investment - water logging

- behaviour - fee structure - water saving equipment

Pathogens (bacteria, viruses, helminths)

high very low low - infections - ‘no’ faeces in water - hygienic handling - aerobic treatment - minimize exposure

5.5 2 Organic matter BOD kg/p/year Excreta 7.5

10 -deplete oxygen

-bacteria growth

Physical, aerobic, anaerobic treatment

0.2 0.4 0.05-0.3 Phosphorus kg/person/year

-eutrophication urine separation, precipitation, etc

0.5 4 0.5 Nitrogen

kg/person/year Mean value 5.0 -eutrophication

-consume oxygen

urine separation, aerobic/anaerobic

Heavy metals present negligible present -toxic to humans use other products

Organic toxic compounds

negligible negligible present -toxic to humans Aerobic treatment

Pharmaceutical residue/hormone

present negligible negligible -toxic for aquatic Degrade in top soil

Courtesy of Peter Ridderstolpe, WRS, Uppsala, Sweden

What do we put into the water?

Detergents can contain (check list of contents on package)– Phosphorous  in water and  on soil– which can be replaced by potassium   or – Salts: sodium  or  – Bleaches: chlorine  and peroxide – Fluorescent whitening agents  – Non-degradable substances:    zeolites  or      and  fillers  or  

What is in soap, detergents, shampoos, solvents, disinfectants, paints, medicines, pharmaceuticals, etc ?

Courtesy of H. Jönsson, Swedish University of Agricultural Sciences, Sweden

Soap contains alkali salts with long-chained fatty acids:  Hard soap usually contains sodium (Na)   Liquid soap usually contains potassium hydroxide (K) 

Toxic organic compounds

Phthalates

(ß-D- Glc -IPM)

OHO

OHO

P

O

NH

NHCl

Cl

Ifosfamide

0% biodegradable

OP

O

NH

NH Cl

Cl

HO

Glufosfamide

70% biodegradable, improved up-take in the gut

Source: Kümmerer, 2007

Metals in wastewater & excreta

1. 2. 3. 4. 5. 6.

ElementDaily intake(mgr)

Output in faeces

(mgr/kg P)

Found in sludge

(mgr/kg P)

Quotient Output in urine

(mgr/kg P)

Quotient

Copper Cu 1,400 1,000 14,000 14 68 206

Chromium Cr 300 214 1,300 6 0.65 2,000

Nickel Ni 120 88 720 8.3 16 78

Zinc Zn 11,000 7,200 25,000 3.5 424 69

Lithium Li 17 12

Mercury Hg 5 3,5 40 11 0.64 63

Lead Pb 23 16 1,500 94 16 94

Cadmium Cd 14 10 44 4 0.32 137

23

53

Courtesy of G. Lindgren, Sweden

Can we cope with the chemical society ?

30 000 chemical

compounds

”treatment”

29 980 unknowns

20 monitored

What we know:

1. Metals and man-made organic material do NOT disappear, but

2. ... they may adsorb to particles

3. Organics decompose into ...

4. inorganic substances and gas, but do NOT disappear

Jan-Olof Drangert, Linköping University, Sweden

Minimise water use, reduce contamination by chemicals, oil, particles, fats, excreta

Storage of urine/faeces,

septic tank,

grease filter, screen, etc.

Aerobic process:- Trickling filter

- Soil/sand filter

- Mulch filter

- Vertical flow con- structed wetland

- Ponds– facultative maturation etc. Anaerobic process:

- Anaerobic baffled reactor- Anaerobic pond

Service waterResorption

Surface irrigation

Sub-soil irrigation

Infiltration

To surface water

Quality of material & workmanship is a FIRST priority!

Usages:

Courtesy of Peter Ridderstolpe, WRS, Uppsala, Sweden

A: Source control comes first

Households can contribute – NOW!

Use as little water as possible by mimicking the use of water in buckets (do not wash under running tap, take quick showers, mend leaking taps, put full loads in washing machines, ...... ) 

Do NOT add solid matter to water (put food scraps from plates and utensils in the waste bin, do not flush tooth picks etc. down the toilet, do not put cigarette butts in urinal, ...... )

Do NOT add chemicals and oils to the water while using it (put fat from frying pan in the solid waste bin, use biodegradable soap and detergent, do not flush paint, medicines or other chemicals down the toilet, .... )

Buy and use environmentally friendly products for your home

Then you can use greywater in your garden, and you avoid blockagesJan-Olof Drangert, Linköping university, Sweden

Households can invest: install proper devices in your kitchen and bathroom

When you build or retrofit your home:

- Buy water- and energy-saving devices e.g. water-efficient     shower heads, taps, washing machines and low-flush toilets

-  Install a dry or low-flush urine-diverting toilet to recover     nutrients and to save water

-  Avoid leaking taps and keep a record of the amount of water used every now and then to monitor your usage

Example: A new suburb in Stockholm, Sweden with proper   saving devices achieved (www.stockholmwater.se): -   a 40 % reduction in water use-   a 25% reduction in hot water use (= energy saving)-   a 50% reduction in eutrophying substances to the lake

Jan-Olof Drangert, Linköping university, Sweden

”Benign by design” - manufacturers need not make products with problematic content

Classical view on functionality of chemical products:

+ stable (persistent)

+ effective

+ efficient

+ affordable

New view: + complete and fast degradation

+ no risk of harmful effects

TPS non-biodegradable for washing powder

Source: Kümmerer, 2007

LAS readily biodegradable replacement of TPS

+ effective

+ efficient

+ affordable

0

50

100

150

200

250

300

350

400

1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006

Henriksdal Bromma

Nonylphenol in digested sludge in Stockholm, mg/kg d.m.

Supervision: nonylphenol in car care products

mg/kg dry

matter

Nonylphenol in digested

sludge

Car wash

New law

Courtesy of Arne Jamtrot, Stockholm City

Media attention: Triclosan in toothpaste

MEDIA Reports

”Your toothpaste

is full of poison”

% in 2010: 000 00 00 0 00 0 0

% in 2006:

Courtesy of Arne Jamtrot, Stockholm City

% of toothpastes containing triclosan

Section of sewer with Hg nuggets

Subsidies: Hg in sewers at dental clinics

Did the campaign make a difference?

280 kg mercury was removed 1998 and 2004

Courtesy of Arne Jamtrot, Stockholm City