Chemistry is all about environment. Waste Water Treatment is related to Environmental Chemistry. This Presentation show a view of waste water composition and its treatment facilities available.

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Prepared By
A.S.M. Asadur Rahman
ID: 1214010 Reg: 900087
Department of
Chemistry
Comilla University
Presentation On

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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%)
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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.

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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.
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Countless fish died in
Greenwich bay in 2003 when DO
reached critically low levels for
an extended time

6. Models of treatment Plant
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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.
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Primary Treatment Process

8. It is biological process to convert organic matter
into bacterial biomass and carbon dioxide, followed
by settling process.
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Secondary Treatment Process
Biological waste water treatment
Aerobic
• Activated Sludge
process
• Trickling filters
• Stabilization lagoons
Anaerobic
• Contact beds
• Anaerobic ponds

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Typical performances for various methods of sewage Treatment

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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.
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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.
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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.
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14. Overall water treatment process
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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
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