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प्रश्न
What is the key difference between primary and secondary sewage treatment?
उत्तर
Sewage is treated in a sewage treatment plant so that it can be free from pollution. This treatment is completed in two stages -
- Primary treatment - In primary treatment, mainly large and small particles are separated by physical processes such as sedimentation, filtration, flotation etc. First of all, floating garbage is removed by filtration. After this, grit soil and small particles are separated by sedimentation. The fine particles settle down as primary sludge and supernatant effluent is formed. The effluent is taken from the primary treatment tank for secondary treatment.
- Secondary treatment - Microorganisms are used in secondary treatment. For example, an oxidation pool is a shallow reservoir collecting sewage. Due to the high amount of organic matter in it, algae and bacteria start growing well.
The bacteria decompose and the algae use the carbon dioxide they produce in photosynthesis. The oxygen released in photosynthesis protects the water from getting contaminated. Thus, an oxidation pool is an example of symbiosis between algae and bacteria. Infectious bacteria are destroyed by the processes taking place in the oxygen pool and only harmless substances remain after the decomposition of organic matter. After secondary treatment, the effluent from the plant is usually released into natural sources of water such as rivers, springs etc. or for tertiary treatment, after separating nitrogen and phosphorus salts from it through chemical processes, the effluent is released into reservoirs.
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संबंधित प्रश्न
Describe how do 'flocs' and 'activated sludge' help in Sewage Treatment.
Removal of large pieces of floating debris, oily substances, etc. during sewage treatment is called _______________.
Why is this sewage water treatment essential?
What are flocs with respect to sewage treatment?
Small part of activated sludge is passed back into primary sedimentation tank.
If the above statement is correct then rewrite as it is and in case it is incorrect then reframe it.
Rearrange the names of tanks used in sewage treatment as per the flow of the procedure.
- Settling tank
- Grit Chamber
- Aeration tanks
- Primary sedimentation tank.
After which of the following process effluents from anaerobic sludge digesters are released in natural water bodies?
Which of the following occurs during tertiary treatment?
Which of the following is/are found in discharge from industrial waste?
In the process of biogas production which of the following anaerobic bacteria are used?
Identify the INCORRECT statement with respect to sewage treatment.
During tertiary treatment, the bacterial floes sediment in the sedimentation tank, this sediment is called ____________.
In a sewage treatment plant, all of the following processes belong to secondary treatment except:
Activated sludge should have the ability to settle quickly so that it can ______.
Why do we prefer to call secondary waste water treatment as biological treatment?
Ganga has recently been declared the national river. Discuss the implication with respect to pollution of this river.
In what way anaerobic sludge digestion is important in sewage treatments?
Which one is wrongly matched?
The aeration tank of a sewage treatment plant is not functioning properly. Explain in detail the impact of this on the treatment of sewage and BOD of the effluent.
