1. 1 NORWEGIAN UNIVERSITY OF LIFE SCIENCES www.umb.no Department of Plant and Environmental Sciences P.D. Jenssen 1 Water treatment processes Petter D. Jenssen and Manoj Pandey** Professor, Norwegian University of Life Sciences (UMB) ** Assistant professor, Tribhuvan University, Nepal THT282 Introduction to sustainable water and sanitation

2. 2 NORWEGIAN UNIVERSITY OF LIFE SCIENCES www.umb.no Department of Plant and Environmental Sciences 7 90% of the worlds wastewater does not receive any treatment (Corcoran et al. 2010) Department of Plant and Environmental Sciences, P.D. Jenssen

3. 3 NORWEGIAN UNIVERSITY OF LIFE SCIENCES www.umb.no Department of Plant and Environmental Sciences P.D. Jenssen 3 Phosphorus is the major agent triggering eutrophication (algeal blooms) in freshwaters

4. 4 NORWEGIAN UNIVERSITY OF LIFE SCIENCES www.umb.no The North Sea Photo: R. Gjørven Nitrogen is considered the main element triggering eutrophication in saltwater

5. 5 NORWEGIAN UNIVERSITY OF LIFE SCIENCES www.umb.no Department of Plant and Environmental Sciences P.D. Jenssen 5 Green algae in a stream in Norway at 1200 meters altitude

6. 6 NORWEGIAN UNIVERSITY OF LIFE SCIENCES www.umb.no Department of Plant and Environmental Sciences P.D. Jenssen 6 Nitrogen can cause algea growth in freshwater in alpine regions

7. 7 NORWEGIAN UNIVERSITY OF LIFE SCIENCES www.umb.no Department of Plant and Environmental Sciences P.D. Jenssen 7  DO less than 1 mg/l  BOD - 250 mg Kathmandu, Nepal Dry season: (Pandey et al. 2005)

8. 8 NORWEGIAN UNIVERSITY OF LIFE SCIENCES www.umb.no Department of Plant and Environmental Sciences P.D. Jenssen 8  DO less than 1 mg/l  BOD - 250 mg Kathmandu, Nepal Dry season: (Pandey et al. 2005) Putrification

9. NORWEGIAN UNIVERSITY OF LIFE SCIENCES www.umb.no 9 Wastewater treatment - removal parameters The objectives of sewage treatment will always include the reduction of the concentration of at least one of the below constituents:  Suspended solids;  Organic (biodegradable) material;  Nutrients (nitrogen and phosphorous);  Pathogenic organisms (expressed as E. Coli)  Medicine residues, organic chemicals (POP´s)  Heavy metals Department of Plant and Environmental Sciences, P.D. Jenssen

10. NORWEGIAN UNIVERSITY OF LIFE SCIENCES www.umb.no 10 Methods of Removal The contaminants in wastewater are removed by different unit processes:  Physical (sedimetation, flotation, screening, filtration)  Biological (trickling filters, RBC, activated sludge)  Chemical (chemical precipitation, ozonation, chlorination) Department of Plant and Environmental Sciences, P.D. Jenssen

11. NORWEGIAN UNIVERSITY OF LIFE SCIENCES www.umb.no Department of Plant and Environmental Sciences, P.D. Jenssen 11 Wastewater Treatment – Processes PrimarySecondary Tertiarary Sludge treatment Remove organics and ammonia Remove nutrients and pathogens

12. NORWEGIAN UNIVERSITY OF LIFE SCIENCES www.umb.no 12 Methods of Removal Physical Unit Processes (mainly primary) Treatment methods in which the application of physical forces predominates are known as physical unit operations. Typical unit operations are: –Screening –Sedimentation –Floatation –Membrane filtration* (< 1um) *Tertiary treatment Salsnes filter Department of Plant and Environmental Sciences, P.D. Jenssen

13. NORWEGIAN UNIVERSITY OF LIFE SCIENCES www.umb.no 13 Membrane Filter Technology (tertiary)  Sette inn egne bilder av membraner Department of Plant and Environmental Sciences, P.D. Jenssen

14. NORWEGIAN UNIVERSITY OF LIFE SCIENCES www.umb.no 14 Membrane Filter Technology Department of Plant and Environmental Sciences, P.D. Jenssen

16. NORWEGIAN UNIVERSITY OF LIFE SCIENCES www.umb.no Department of Plant and Environmental Sciences, P.D. Jenssen 16 Wastewater Treatment – Processes PrimarySecondary Tertiarary Sludge treatment Remove organics and ammonia Remove nutrients and pathogens

17. NORWEGIAN UNIVERSITY OF LIFE SCIENCES www.umb.no 17 Methods of Removal (Contd.) Biological Unit Processes (mainly secondary) The treatment method in which the removal of contaminants is brought about by biological activity are known as biological unit process. Some examples are: –aerobic processes - presence of dissolved oxygen Biofilters Trickling filters Activated sludge –anaerobic processes – absence of dissolved oxygen Denitrification (tertiary) Septic tanks Ponds Department of Plant and Environmental Sciences, P.D. Jenssen

18. Biofilter Porous media LWA Diam: 2,5 mm Surface area > 5000m 2 /m 3 Bacteria on LWA surface

19. 19 NORWEGIAN UNIVERSITY OF LIFE SCIENCES www.umb.no Wastewater spraying over a biofilter 19 Department of Plant and Environmental Sciences, P.D. Jenssen

20. 20 NORWEGIAN UNIVERSITY OF LIFE SCIENCES www.umb.no Biofilter: trickling filter (fixed biofilm) 20 Department of Plant and Environmental Sciences, P.D. Jenssen

21. 21 NORWEGIAN UNIVERSITY OF LIFE SCIENCES www.umb.no Biofilter: Rotating biological contactor - RBC (fixed biofilm) 21 Department of Plant and Environmental Sciences, P.D. Jenssen

22. 22 NORWEGIAN UNIVERSITY OF LIFE SCIENCES www.umb.no 22 Activated sludge at Ryaverket Gothenburg 700 000 pe Department of Plant and Environmental Sciences, P.D. Jenssen Biological treatment: Activated sludge (biofilm in suspension)

23. NORWEGIAN UNIVERSITY OF LIFE SCIENCES www.umb.no Department of Plant and Environmental Sciences, P.D. Jenssen 23 Wastewater Treatment - Processes PrimarySecondary Tertiarary Sludge treatment Remove organics and ammonia Remove nutrients and pathogens

24. NORWEGIAN UNIVERSITY OF LIFE SCIENCES www.umb.no 24 Methods of Removal (Contd.) Chemical Unit Process (tertiary) Treatment methods in which the removal or conversion of contaminants is brought about by the addition of chemicals or by chemical reactions are known as chemical unit processes. Some of the most common are: –Precipitation (lime, Fe- of Al salts, Struvite formation) –Adsorption –Disinfection Department of Plant and Environmental Sciences, P.D. Jenssen

25. NORWEGIAN UNIVERSITY OF LIFE SCIENCES www.umb.no 25 Methods of Removal (Contd.) Chemical Unit Process (tertiary) Treatment methods in which the removal or conversion of contaminants is brought about by the addition of chemicals or by chemical reactions are known as chemical unit processes. Some of the most common are: –Precipitation –Adsorption (Ion exchange) –Disinfection Department of Plant and Environmental Sciences, P.D. Jenssen

26. NORWEGIAN UNIVERSITY OF LIFE SCIENCES www.umb.no 26 Methods of Removal (Contd.) Chemical Unit Process (tertiary) Treatment methods in which the removal or conversion of contaminants is brought about by the addition of chemicals or by chemical reactions are known as chemical unit processes. Some of the most common are: –Precipitation –Adsorption –Disinfection (chlorination, UV-light, Ozone) Department of Plant and Environmental Sciences, P.D. Jenssen

27. NORWEGIAN UNIVERSITY OF LIFE SCIENCES www.umb.no 27 Water and sludge treatment process at Bekkelaget PrecipitationPrimary 1900 l/s<Q< 4000 l/s Q=1900 l/s PAX-18 Q<1900 l/s Biogas- upgrading Department of Plant and Environmental Sciences, P.D. Jenssen

28. 28 NORWEGIAN UNIVERSITY OF LIFE SCIENCES www.umb.no Department of Plant and Environmental Sciences, P.D. Jenssen Removal efficiency % 28 ParameterPrimarySecondaryTertiary SS50 - 8080 - 90>90 BOD20 - 4070 - 90>90 P<1030>90 N<103070 E. Coli1 log2 -3 log3 - 5 (7)* logs *with disinfection