Waste Water Treatment
- 1. 12/14/2018 1 Prepared By A.S.M. Asadur Rahman ID: 1214010 Reg: 900087 Department of Chemistry Comilla University Presentation On
- 2. 12/14/2018 2 Waste water & its origin Waste water is any water that adversely affected in quality by anthropogenic influence. Origin of waste water: • Domestic used water • Industrial Discharge • Surface ran-off or storm water and Infiltration • Commercial used water • Agricultural run-off • Community waste water(Sewage)
- 3. Water(more than 95%) 12/14/2018 3 Composition of wastewater Name Example Pathogens Bacteria, Viruses, prions & parasitic worms Organic Particles Hairs, food, paper fibers, plant material, humus Soluble Org. Material Urea, Soluble proteins, drugs, sugars , Pharmaceuticals etc. Inorganic Particles Sand, Grit, metal particles etc. Soluble Inorg. Material Ammonia, road-salt, sea-salt, cyanide, hydrogen sulfide, thiocyanates etc. Animals Protozoa, insects, arthropods Macro solids Children toys, nappies, dead animals or plants, Gases Carbon di oxide, methane etc. Emulsions Paints, adhesives, hair colorants, emulsified oils Toxins Pesticides, poisons, herbicides etc.
- 4. 12/14/2018 4 Definition And Its Classification Wastewater treatment is collectively the industrial scale process that makes water more acceptable for reuse or to discharge in nature which then can't affect the aquatic life and water quality. Classification Primary method Secondary method Tertiary/Advanced method
- 5. Why wastewater treatment is necessary Main causes • Produce dangerous level of toxic chemicals or organisms. • Produce excess algal nutrients. • Wastes are contaminate water & consume the dissolved oxygen. 12/14/2018 5 Countless fish died in Greenwich bay in 2003 when DO reached critically low levels for an extended time
- 6. Models of treatment Plant 12/14/2018 6 Wastewater-treatment-plant-in-India Wastewater-treatment plant in South Australia
- 7. The treatment refers to sedimentation, the physical treatment process that is used to remove settle able suspended solids from waste water. 12/14/2018 7 Primary Treatment Process
- 8. It is biological process to convert organic matter into bacterial biomass and carbon dioxide, followed by settling process. 12/14/2018 8 Secondary Treatment Process Biological waste water treatment Aerobic • Activated Sludge process • Trickling filters • Stabilization lagoons Anaerobic • Contact beds • Anaerobic ponds
- 9. 12/14/2018 9 Typical performances for various methods of sewage Treatment
- 10. 12/14/2018 10 Activated Sludge Process Pathways for the removal of BOD
- 11. It may use biological or physical chemical treatment process to remove water contaminants not removed by primary & secondary treatment ,such as nutrients, toxic materials or additional suspended solids & BOD removal. 12/14/2018 11 Tertiary treatment process Steps of the treatment: • Coagulation sedimentation • Disinfection • Filtration • Reverse osmosis
- 12. • Coagulation Sedimentation: Is used to increase the removal of solids from effluent. • Disinfection: Is an attempt to destroy the pathogenic organisms in the effluent, Chlorination mostly used. • Filtration: Methods are available to ensure high quality water. Sand filtration, Activated carbon & membrane filtration used. • Reverse Osmosis: Pressure is used to force effluent that retains contaminants on one side & clean water pass to other side. 12/14/2018 12
- 13. Final Product After treatment of waste water Water, which one portion is suitable for drinking and the other portion is suitable for discharge in nature. Solid sludge that must be undergo further disposal. 12/14/2018 13
- 14. Overall water treatment process 12/14/2018 14
- 15. General consideration of selection of treatment process • Flow range & Variation • Influent waste water characteristics • Climate enclosure • Plant performance • Operational consideration • Reliability of the process • Compatibility • Land requirement • Environmental Constraints • Overall cost 12/14/2018 15
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