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1 Greywater treatment and reuse Professor Dr. P. D. Jenssen Norwegian University of Life Sciences (UMB) Appropriate sanitation for the developing world, August 16, 2006 Photo: R. Gjørven Source separation of wastewater Presentation overview Greywater production Nutrients in waste fractions Greywater composition Greywater treatment and reuse (Alsen and Jenssen2005) Nutrients and volume of domestic wastewater fractions 100 % 90 % 80 % 70 % 60 % 50 % 40 % 30 % 20 % 10 % 0 % Nitrogen Phosphorous Potassium Volume Greywater Faeces Urine (Vinnerås 2002). 1

2 Liter/person & day Greywater volumes per capita and day liter liters Greywater composition Parameters Country/Reference BOD5 COD SS Tot N NH4 Kjeldahl N Tot P Faecal coliforms (mg/l) (mg/l) (mg/l) (mg/l) (mg/l) (mg/l) (mg/l) (log/100ml) Sweden/Olsson et ,1 18,1 6,15 al., 1968 Canada/Brandes, ,5 1,7 11,3 1,4 a 6, Norway/Kristiansen ,5 1,3(0,42 b ) 5,08 and Skaarer, 1979 USA 1 /Siegrist and ,9 4,4 6,2 Boyle, 1981 Sweden norm/naturvrdsverket, ,7 4(1,0 b ) Norway 1 /Rasmussen ,2 36,1 3,97 et al., 1996 Australia/CEHBDH, , , Norway 1 /Jenssen ,8 3, ,0 b Sweden proposed ,6 5,2 norm /Vinners et al Germany/Li et al. 73-8,7-2,5 6,8-9, ,1 Malaysia 1 /Jenssen et ,6 22,2 2,4 5,8 al Septic tank effluent, a excluding laundry, b phosphorus-free detergents (Jenssen et al. 2005a) Greywater composition Greywater concentration Source Phosphorus Nitr ogen g/ p and year mg/l g/ p and year mg/l Torvet ua* 58 1, ,1 Kaja* 56 0, ,2 Vinnerås , ,2 *Measured in septic tank effluent (STE) BOD/COD/SS concentrations as for combined wastewater Nutrients (nitrogen and phosphorus) substantially lower concentrations than for combined wastewater Pathogens (bacteria, viruses) substantially lower concentrations than for combined wastewater 2

3 Greywater constituents relative concern Greywater treatment options nitrogen phosphorus of the organic matter bacteria + virus? (Illustration: Jenssen et al. 2005) Greywater treatment options Package treatment - Rotating biological contactors (Illustration: Jenssen et al. 2005a) Package treatment - Rotating biological contactors BOD reduction Bacteria reduction Rotating biological contactors removes: BOD 90% SS >60 Total P 30% Total N 30% Bacteria: needs UV to meet swimming water quality 3

4 Membrane filtration of greywater Greywater treatment options ) Phota: P.D. Jenssen (Illustration: Jenssen et al. 2005a) Tingvall conference center - Sweden POND 1 Septic tank chamber1 POND 2 Septic tank chamber2 Pond 3 Ponds at Tingvall conference center- Sweden Three ponds in series removes: BOD 90% SS 90% Total P >30% Total N >30% Bacteria: very good - swimming water quality Greywater treatment in ponds Greywater treatment options Limited experience Area requirement: 1-5m 2 /person ( ) (Illustration: Jenssen et al. 2005a) 4

5 Infiltration systems - loading rates Large open infiltration system in a sand deposit Open systems - infiltration in ponds cm/d Subsurface (buried) systems - infiltration trenches Illustrations: Jenssen and Siegrist 1991 Photos: P.D. Jenssen 1-5 cm/d Photo: K. Robertsen Large buried infiltration system in a sand deposit Subsurface infiltration and sandfilter Sandfilter Photo: K. Robertsen Trench Photos: P.D. Jenssen Photo: P.D. PDJ Jenssen 1999 Mound Loading rate assessment diagram Md/So (Meso) diagram Buried infiltration systems pollutants of concern; combined wastewater Wastewater source Sorting ( d 60 /d 10 ) K (m/d) 1,3 L.R. (cm/d) 2-2, > ,0 4,0 Soil Ground water Pretreatment Effluent delivery Organic matter P NO 3 Bacteria Virus Infiltration area Clogging zone Percolation GW recharge Well (Siegrist et al. 2000) (Jenssen & Siegrist 1991) Mean grain size (d 50 ) 5

6 Buried infiltration systems pollutants of concern; greywater Infiltration systems treatment efficiency Wastewater source Soil Ground water Pretreatment Effluent delivery Organic matter Bacteria Virus? Infiltration area Clogging zone Percolation GW recharge Well (Siegrist et al. 2000) (Photo: P.D. Jenssen) BOD > 90% SS > 90 Total P >90% Total N 30-90% Bacteria - very good, swimming water quality Greywater treatment options Constructed wetland with subsurface flow (P.D. Jenssen et al. 2005a) (Illustration: T. Mæhlum) Constructed wetland with integrated and separate pretreatment filter The size of the horisontal subsurface flow wetland sectio based on 15 years of P-sorption Domestic WW: 7-9 m3/pe Greywater: 2-3 m3/pe 7 40 m 2 /family ( Jenssen and Heistad 2000) (Illustration: Maxit Group) 6

7 Greywater - 1/4 the area of greywater +WC Greywater treatment Septic tank Pump/siphon Pretreatment biofilter (Photo: P.D. Jenssen) Level control & sampling port Horizontal subsurface flow wetland filter Constructed wetland at Dal primary school Norway Constructed wetland flow direction/purification Photos: P.D. Jenssen Parameter Influent Effluent mg/l mg/l Total - P 2,9 0,2 Total - N 29,0 12,0 COD SS < 5 T. coli. /100ml < 2 (Jenssen et al. 2005b) High quality effluent Pretreatment biofilter performance Dome with TF- nozzle BOD removal: 70-80% Complete nitrification Total-N removal 5-40% SS 60-70% Bacteria reduction: up to 5 logs 2m QuickTime and a Photo - JPEG decompressor are needed to see this picture. Grain size: 2-10 mm Depth: cm Area: 0,3-2,0m 2 /person (Jenssen et al. 2005b) 7

8 Pretreatment biofilter Porous media LWA Diam: 2,5 mm Pretreatment biofilter removal of virus Bacteriophage PRD 1 adsorbed to the biofilm surface Surface area > 5000m 2 /m 3 Surface area > 5000m 2 /m 3 Bacteria on LWA surface (Heistad 2005) Monodisperse particles (1um) Ingested by microorganism Student dormitories in Norway Studentboliger Kaja 48 students Vacuum toilets Local greywater treatment Greywater treatment student housing Norway Effluent values Total - P 0,04 mg/l Total - N 2,2mg/l PBF BOD 3,9 mg/l Termotolerant coli <100 Wetland 48 students Wetland area: 2 m 2 /student Foto: P. Jenssen Torvetua - Local greywater treatment Treatment results BOD <10 mg/l Phosphorus 0,2 mg/l > 80 % Nitrogen: 3,0 mg/l 40-70% Bacteria: swimming water quality Torvetua Norway 42 condominiums vacuumtoilets Local greywater treatment 8

9 Kuching Malaysia Photo: P.D. Jenssen Pilot project Hui Sing Garden Greywater treatment Greywater treatment Septic tank Pump/siphon Pretreatment biofilter Level control & sampling port Horizontal subsurface flow wetland filter 1 st chamber of oil and grease trap Pump sump Final discharge Photo: Y. Fevang Photo: P.D. Jenssen Greywater treatment - Malaysia (Jenssen et al c) Preliminary results: BOD < 2 mg/l Total N 2.2 mg/l Total P 1.9 Faecal coliforms 50/100ml Greywater treatment in urban areas - OSLO NORWAY Klosterenga Photo: Y. Fevang Photo: P.D. Jenssen 9

10 Greywater Klosterenga treatment oversikt in OSLO Pretreatment Biofilter (PBF) Greywater treatment Klosterenga Oslo Pretreatment biofilter: 10 domes 60 cm 2-4mm LWA 33 apartments 100 persons Area 1m 2 /person Horisontal subsurface flow CW Horizontal subsurface flow filter: 100 m 3 FiltraliteP TM 1,8 m deep Pretreatment biofilter (PBF) Klosterenga - under construction PBF Greywater treatment at Klosterenga Oslo Effluent values: Termotolerant coliform bacteria: 0 Total-N: 2,5 mg/l Total-P: 0,02 mg/l P-sorption capacity; approx. 50 years Agricultural use of water and nutrients from constructed wetlands Photo: P.D. Jenssen Inhouse use? Greywater treatment at Klosterenga Oslo Effluent values: Fecal coliforms: 0 Total-N: 2,5 mg/l Total-P: 0,02 mg/l 10

11 Local discharge Irrigation Conclusions Groundwater recharge Photos: P.D. Jenssen Compact reliable RBC systems are available for decentralized greywater treatment Investment and maintenance costs are high for RBC systems Conclusions Conclusions Infiltration are well suited for greywater disposal and treatment and much experience exist Infitration systems have very low investment and operational cost Infiltration systems have excellent bacteria removal capability and recharge groundwater aquifers A simple vertical flow biofilter followed by a horizontal flow wetland filter is developed for greywater treatment The area requirement is 1-2 m 2 / person which facilitates use in urban settings High quality effluent that meets swimmig water standard with respect to indicator bacteria is produced The effluent is suitable for irrigation, groundwater recharge or local discharge The effluent constitute an excellent raw water for upgrading to inhouse use. 11

12 Ecosan education The Norwegian University of Life Sciences Thank you! MSc programs Short courses Norwegian University of Life Sciences Main references Alsén K.W. and P.D. Jenssen Ecological Sanitation for mankind and future. Information folder prepared for the UN-conference CSD-13 New York April. Heistad A Virus removal in porous media. PhD thesis under preparation. Department of Mathematical Sciences and Technology, Norwegian University of Life Sciences, Ås Norway. Jenssen, P.D. and R.L. Siegrist Integrated loading rate determinations for wastewater infiltration systems sizing. On-site wastewater treatment. Proc. 6th Symposium on Individual and Small Community Sewage Systems Dec Chichago Illinois. ASAE Publ , pp Jenssen P.D. and A. Heistad Natuyrbasert avløpsteknologi. Kompendium. Department of Mathematical Sciences and Technology, Norwegian University of Life Sciences, 1432 Ås, Norway. Jenssen, P. D. and L. Vråle Greywater treatment in combined biofilter/constructed wetlands in cold climate In: C. Werner et al. (eds.). Ecosan closing the loop. Proc. 2 nd int. symp. ecological sanitation, Lübeck Apr , GTZ, Germany, pp: Jenssen P.D., J. Heeb, K. Gnanakan and K. Conradi Ecosan Curriculum, GTZ/UNEP,. Jenssen P.D., T. Mæhlum, T. Krogstad and Lasse Vråle. 2005b. Treatment Performance of Multistage Constructed Wetlands for Wastewater Treatment in Cold Climate. Journal of Environmental Science and Health. Vol 40 (6-7) Jenssen P.D., L. Seng, B. Chong, T. H. Huang4, Y. Fevang, I. Skadberg, 2005c. An urban ecological sanitation pilot study in humid tropical climate. Proc. 3rd. International conference on ecological sanitation. Durban, South Africa pp Siegrist, R.L., Tyler, E.J., Jenssen, P.D Design and peformance of onsite wastwater soil absorption systems. Paper presented at National Research Needs Conference Risk-Based Decision Making for Onsite Wastewater Treatment, St. Louis, Missouri, May USEPA, Electic Power Research Inst. Community Env. Center, National Decentralized Water Resources Capacity Development Project. Vinnerås, B Possibilities for sustainable nutrient recycling by faecal separation combined with urine diversion. Agraria Doctoral thesis. Swedish University of Agricultural Sciences, Uppsala. 12