4.7 Greywater treatment

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

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

3. Overview of possible technical options Karin Tonderski, Linköping University, Sweden

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

5. Sedimentation pond Karin Tonderski, Linköping University Sweden

6. CH4, CO2 scum layer sludge Anaerobic pond inflow outflow Karin Tonderski, Linköping University, Sweden

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

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

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

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

11. Free-floatingplants Floating-leaved plants Emergent plants Submerged plants Downflow Surface flow (FWS) Sub-surface flow Upflow Horizontal flow (HF) Vertical flow (VF) Hybrid systems Constructed wetlands - classification 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. Horizontal subsurface flow wetlands o2 o2 o2 o2 Internal water level Cross distribution trench Cross collection trench Collection and drainage pipe Influent Outlet shaft Main filter filled with graded gravel and sand Effluent Courtesy of Roshan Shrestha, UN-Habitat, Nepal

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

16. Vertical flow subsurface wetland o2 o2 o2 o2 Collection and drainage pipe Influent Main filter filled with graded gravel and sand Effluent 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 10 m Geotextileunit Pre- treatment in sedimentation tank 0.6 m in sand 3 m in silt Courtesy of Peter Ridderstolpe, WRS. Sweden

20. Biofilter and wetland for greywater treatment Biofilter with nozzle distribution Wetland Total area 100 m2 Courtesy of Thor-Axel Stenström, SMI, Sweden

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

22. Mulch bed filter Greywater pipe from household Mulch from garden Depth max. 40 cm Entrance with stones 3-10 litres of greywater per m2 per day Courtesy of Kim Andersson, Colombia

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

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

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

26. Removal rate of microorganisms in various wastewater treatments (log units) 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

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 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 Sludge drying bed We decide what quality we would like the final products to have. CO2 & methane gases Dried sludge itself Percolating effluent water Jan-Olof Drangert, Linköping University, Sweden

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

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: mix as few flows as possible Jan-Olof Drangert, Linköping University, Sweden