190 likes | 397 Views
4.5 Greywater is man-made. – an untapped water and nutrient resource . Greywater (shower, washing, cleaning, etc.). constructed wetland, gardening, wastewater pond, biol. treatment, membrane- technology. irrigation, groundwater recharge or direct reuse. Learning objective :
E N D
4.5 Greywater is man-made – an untapped water and nutrient resource Greywater (shower, washing, cleaning, etc.) constructedwetland, gardening, wastewater pond, biol.treatment, membrane-technology irrigation, groundwater recharge or direct 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
Urban horizontal water and nutrient flows Rain Jan-Olof Drangert, Linköping University, Sweden
Urban unintended vertical flows of contamination Landfill Sludge bed Septic tank Petrol station Pit latrines Irrigation Sewers Soil layer with organic material, clays and charged particles Groundwater (saturated aquifer) Jan-Olof Drangert, Linköping University, Sweden
The effects of urbanisation on groundwater utilisation, quantity and quality Water volumes (supply & disposal) Imported water time Periurban wells Deeper wells Settlement size Shallow wells Effect on quantity:None Falling grw-levelOver extraction Excess infiltration Effect on quality:None Growing pollutionExcessive pollution Courtesy of G. Jacks, Royal Institute of Technology, Stockholm
All groundwater under cities is polluted Source: Powell et al., 2003
Wastewater = clean water + what has been added Courtesy of Peter Ridderstolpe, WRS, Uppsala, Sweden
What do we put into the water? What is in soap, detergents, shampoos, solvents, disinfectants, paints, medicines, pharmaceuticals, etc ? • Soapcontains alkali salts with long-chained fatty acids: • Hard soap usually contains sodium (Na) • Liquid soap usually contains potassium hydroxide (K) • Detergentscan 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 Courtesy of H. Jönsson, Swedish University of Agricultural Sciences, Sweden
Toxic organic compounds O Cl Ifosfamide O NH P Cl NH 0% biodegradable HO O O Cl O HO NH Cl P OH NH Phthalates Glufosfamide (ß-D- Glc -IPM) 70% biodegradable, improved up-take in the gut Source: Kümmerer, 2007
Metals in wastewater & excreta Courtesy of G. Lindgren, Sweden
Can we cope with the chemical society ? What we know: 1. Metals and man-made organic material do NOT disappear, but 30 000 chemical compounds 2. ... they may adsorb to particles 3. Organics decompose into ... 4. inorganic substances and gas, but do NOT disappear ”treatment” 20 monitored 29 980 unknowns Jan-Olof Drangert, Linköping University, Sweden
A: Source control comes first sludge 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 Usages: Service waterResorption Surface irrigation Sub-soil irrigation Infiltration To surface water Minimise water use, reduce contamination by chemicals, oil, particles, fats, excreta Storage of urine/faeces, septic tank, grease filter, screen, etc. Quality of material & workmanship is a FIRST priority! Courtesy of Peter Ridderstolpe, WRS, Uppsala, Sweden
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, andyou avoid blockages Jan-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 New view: + complete and fast degradation + no risk of harmful effects Classical view on functionality of chemical products: + stable (persistent) + effective + efficient + affordable + effective + efficient + affordable Source: Kümmerer, 2007 TPS non-biodegradable for washing powder LAS readily biodegradable replacement of TPS
Supervision: nonylphenol in car care products mg/kg dry matter Car wash Nonylphenol in digested sludge Applying law on product choice Courtesy of Arne Jamtrot, Stockholm City
Media attention: Triclosan in toothpaste % of toothpastes containing triclosan MEDIA Reports ”Your toothpaste is full of poison” % in 2006: % in 2010:000 00 00 0 00 0 0 Courtesy of Arne Jamtrot, Stockholm City
Subsidies: Hg in sewers at dental clinics Did the campaign make a difference? 280 kg mercury was removed 1998 and 2004 Section of sewer with Hg nuggets Courtesy of Arne Jamtrot, Stockholm City