1. 4.7 Greywater treatment Learning objectives: Get familiar with various treatment options and with the application of various processes Can we remove all the pathogens and heavy metals? What is in the sludge? constructed wetland, gardening, wastewater pond, biol. treatment, membrane- technology Greywater (shower, washing, cleaning, etc.) irrigation, groundwater recharge or direct reuse

2. Application of processes – after source control Jan-Olof Drangert, Linköping University, Sweden Physical Chemical Biological B A E D F G BOD, suspended solids BOD, nitrogen, pathogens phosphorus, pathogens, metals C

3. Overview of possible technical options Treatment:Possible technical solutions for greywater: Physical (SS and BOD-levels) Screen, grease trap, septic tank, sedimentation pond Biological I (BOD-level reduction) ABR, anaerobic filter, UASB, soil filters, reactive filters, trickling/bio-filter, stabilisation pond, sub- surface wetlands, irrigation Biological II (N & pathogen reduction) Nitrification-denitrification in wetland or sandfilter, maturation pond, crop production, mulch beds, overland flow Chemical (P, pathogen, metal removal) soil filters, reactive filters, precipitation pond, irrigation Sludge management Thickeners, centrifuge, sieve, fermentation, lime, drainage bed, reed beds, composting, lime stabilisation Karin Tonderski, Linköping University, Sweden

4. Screens and grease traps Organics from kitchen pipe sorted out in a plastic screen Jan-Olof Drangert, Linköping University, Sweden Screen Over- flow

5. Sedimentation pond Karin Tonderski, Linköping University Sweden

6. Anaerobic pond CH 4, CO 2 scum layer sludge Karin Tonderski, Linköping University, Sweden inflow outflow

7. Sediment Bird’s eye view Sediment Simple septic tank Scum layer Jan-Olof Drangert, Linköping University, Sweden

8. Anaerobic baffled reactor Off-plot system Anaerobic Baffled Reactor (ABR) Pedro Kraemer, BORDA, India

9. Anaerobic Filter (off-plot biogas system) Courtesy of Pedro Kraemer, BORDA, India

10. UASB Reactor Jan-Olof Drangert, Linköping University biogas pump

11. Constructed wetlands - classification Floating-leaved plants Emergent plants Submerged plants Free-floating plants Surface flow (FWS) Sub-surface flow Downflow Upflow Vertical flow (VF) Horizontal flow (HF) Hybrid systems Courtesy of Jan Wymazal, Poland

12. Role of plants in constructed wetlands Free water Horizontal Vertical Hybrid surface flow flow flow ______________________________________________________________ Stabilizing of bed surface +++++ +++++ +++ +++ Prevent clogging - - +++++ +++++ Reduce current velocity +++ - - (++) Attenuation of light +++++ - - (+++) Insulation +++ +++++ +++++ +++++ Attached microbes +++++ +++++ +++++ +++++ Uptake of nutrients ++(++) ++ ++ ++ Oxygen transfer/release + +++ + ++ Habitat for wildlife +++++ +++ + +(++) Aesthetics +++++ +++++ +++++ +++++ Courtesy of Jan Wymazal, Poland

13. Metal removal that may occur in constructed wetlands Source: Kleinmann and Girts, 1987

14. o2o2 o2o2 o2o2 o2o2 Horizontal subsurface flow wetlands Influent Main filter filled with graded gravel and sand Cross distribution trench Cross collection trench Outlet shaft Internal water level Effluent Collection and drainage pipe Courtesy of Roshan Shrestha, UN-Habitat, Nepal

15. Construction of horizontal flow wetlands Karin Tonderski, Linköping University, Sweden

16. o2o2 o2o2 o2o2 o2o2 Vertical flow subsurface wetland Influent Main filter filled with graded gravel and sand Effluent Collection and drainage pipe Courtesy of Roshan Shrestha, UN-Habitat, Nepal (revised)

17. Trickling filter Jan-Olof Drangert, Linköping University, Sweden

18. Soil filters – leachfield or mound systems Jan-Olof Drangert, Linköping University, Sweden

19. Improved distribution using controlled clogging Geotextile unit Pre- treatment in sedimentation tank 0.6 m in sand 3 m in silt 10 m Courtesy of Peter Ridderstolpe, WRS. Sweden

20. Biofilter with nozzle distribution Wetland Total area 100 m 2 Courtesy of Thor-Axel Stenström, SMI, Sweden Biofilter and wetland for greywater treatment

21. kitchen Cajete de acolchado Wash room Bath Registro de división de flujos Bird´s eye view of a mulch bed system for a single house Distribution boxes Mulch beds Courtesy of Kim Andersson, Colombia

22. Mulch bed filter 3-10 litres of greywater per m 2 per day Depth max. 40 cm Mulch from garden Entrance with stones Greywater pipe from household Courtesy of Kim Andersson, Colombia

23. Wetland irrigation and overland flow Karin Tonderski, Linköping University, Sweden

24. Common problems in soil filters & constructed wetlands 1.Overloading (suspended solids, high BOD, water) 2. Uneven distribution (over surface, over clay) 3. Failure in drainage (waterlogging, roots) 4.Wrong choice of sand and gravel (texture, mineral particle shape) 1 2 4 3 Jan-Olof Drangert, Linköping University, Sweden

25. Extensive Intensive Sorption and irrigation systems - Drain mulch basin - Swales & resorption trenches - Wetland irrigation (overland flow & sub- surface flow, and impounding wetlands) Aerobic biofilters and energy Rapid infiltration systems Soil filters: - Infiltration (open, covered submerged) - Sandfilters Artificial filter media: - Indrän, infiltra etc. Biofilter reactors - Trickling filter - Bio-rotors Revised from P. Ridderstolpe, WRS, Uppsala

26. Removal rate of microorganisms in various wastewater treatments (log units) ProcessBacteriaHelminthsVirusesCysts Primary sedimentation: Plain Chemically assisted 0-1 1-2 0-2 1-30-10-1 UASB1-2 Activated sludge0-2 0-1 Sub-surface flow wetland1-22-62-30-2 Aerated lagoon1-21-31-20-1 Slow sand filtration/infiltration2-33-62-33-6 Disinfection2-60-10-40-3 Waste stabilization pond3-61-32-41-4 Large variations in practice due to quality of management Sources: WHO, 2006 and Jimenez et al., 2010

27. Pathogen reductions achieved by selected health-protection measures Control measure Reduction (log units) Comments Wastewater treatment 1-4Usually achieved reduction but depends on type and functionality of the treatment system Drip irrigation: - low-growing - high-growing 2424 Root crops and crops such as lettuce that grow just above but partially in contact with soil. Crops such as tomatoes and fruit trees not in contact. Pathogen die-off0.5-2 per day Die-off on crop surfaces between last irrigation and consumption, depends on sunshine, crop type etc. Crop-washing: - with water - disinfection 1 2-3 Washing salad crops, vegetables and fruit with: clean water. Weak disinfectant and rinsing in clean water. Produce peeling Produce cooking 1-2 6-7 Fruits, cabbage, root crops. Immersion in boiling or close-to-boiling water. Source: Bos, R., Carr, R. and Keraita, B. 2010.

28. E: Treatment of sludge - All treatment processes produce sludge, be it much or little -Choice of treatment according to kind of reuse - We need to de-toxify our chemical society New limits on organics proposed under Option 3 from EU (2008) PAH6 mg/kg dry matter PCB0.8 mg/kg dry matter PCDD/F100 ng ITEQ/kg dry matter LAS5 g/kg dry matter NPE450 mg/kg dry matter Limits Cd Cr Cu Hg Ni Pb Zn Old (mg/kg) 20-40- 1,100- 1,750 16-25300-400 750- 1,200 2,500- 4,000 New 5150 400 5 50 250 600 Source: EU, 2008

29. Start from the end ! (centralised example) Our thinking is now on global challenges as well as on local wishes for system performance and status Percolating effluent water Dried sludge itself We decide what quality we would like the final products to have. Jan-Olof Drangert, Linköping University, Sweden Sludge drying bed CO 2 & methane gases

30. Drying beds and composting for decentralised sludge management Dried sludge itself J-O Drangert, Linköping University, Sweden Source: Water and Wastewater Distance Learning http://water.me.vccs.edu/ Source: WRS Uppsala AB http://www.swedenviro.se/wrs/

31. Principle: Organic ≠ other solid waste Stormwater ≠ sewage Industrial ≠ household wastewater Black toilet water ≠ greywater Faeces ≠ urine Summary of strategies to improve wastewater treatment and nutrient use in agriculture and energy production: Jan-Olof Drangert, Linköping University, Sweden