1. Effluent treatment…….

2. Effluent treatment……
The household sewage and the industrial waste contains organic and inorganic impurities, which can cause potential threat (POT) to plants, animals, or human beings.
Generally effluent is discharged into the following water bodies which causes contamination .
Can make groundwater unfit and soil infertile.
Treatments aim to reduce BOD and COD.

3. Primary treatment……..
Aims at sedimentation of suspended organic particles.
Sewage flows through large tanks(PRE- SETTLING BASINS OR PRIMARY CLARIFIERS).
Here heavy solids settle to bottom while oil and grease and lighter solids float to surface.
Settled and floating materials are removed
Remaining liquid may be discharged or subjected to secondary treatment.

4. SECONDARY TREATMENT….
Removes dissolved and suspended biological matter.
Relies upon m/o
M/o mineralizes suspended organic matter and converts dissolved matter into suspended form.
M/o used in form of biofilm or homogenously suspended .

5. Tertiary treatment…… provide a final treatment stage
improve effluent quality before discharging to receiving environment.
Treated water if disinfected called as EFFLUENT POLISHING.
Waste water contains high levels of nutrients(N,P).
Excessive release to environment lead to EUTROPHICATION (overgrowth of weeds, algae and cyanobacteria).

6. Nutrient = plants require them for growth
Potential problems from nutrients:
water quality
aquatic ecosystem
human & animal health

7. NITROGEN…… Biochemically inter convertable forms :
organic N (proteins, urea)
ammonia gas (NH3)
ammonium ion (NH4+)
nitrate (NO3)
nitrite (NO2)
elemental N2 gas (78% of air)
Mobile (esp. nitrate)
Limiting nutrient in salt waters

8. NITROGEN REMOVAL…… Two-step biological method
Step 1: Aerobic Nitrification
Ammonia to nitrate conversion
m.o: Nitrosomonas
Step 2: Anoxic-anaerobic De nitrification
nitrate to N2 conversion
requires carbon source
m.o.: Pseudomonas
Nitrogen gas is released to atmosphere and thus removed form water.
Sludge is mixed by using SUBMERSIBLE MIXERS

9. PHOSPHORUS REMOVAL…… Forms: organic phosphorus orthophosphate (PO4)
polyphosphates
phosphorus-containing rocks
Binds to soils and sediments
Limiting nutrient in fresh waters

10. PHYSICAL-CHEMICAL REMOVAL..
Chemical precipitation (3 options)
add alum (Al2SO4) to form aluminum phosphate
add ferric chloride (FeCl3)
add lime (CaO)
Coagulation / flocculation
Clarifier/settler

11. BIOLOGICAL REMOVAL…… Called as ENHANCED BOLOGICAL PHOSPHORUS REMOVAL.
Poly phoshphate -accumulating organism(PAO) are used
Enriched selectively
Accumulate large quantities of P within their cells
Biomass enriched with this has a fertilizer value.

12. Thanking you……….