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प्रश्न
Explain the process of secondary treatment given to the primary effluent up to the point it shows significant change in the level of biological oxygen demand (BOD) it.
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उत्तर
The effluent from the primary treatment is passed to aeration tanks where air is pumped into it. The useful aerobic microbes grow into flocs (masses of bacteria associated with fungal filaments) and consume the major part of the organic matter in the effluent which reduces BOD of the effluent. The effluent is then passed into a settling tank where bacterial flocs are allowed to sediment. This sediment is called activated sludge.
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संबंधित प्रश्न
Explain the role of microbes in sewage treatment.
Explain the function of “anaerobic sludge digester” in a sewage treatment plant.
Three water samples namely river water, untreated sewage water and secondary effluent discharged from a sewage treatment plant were subjected to BOD test. The samples were labelled A, B and C; but the laboratory attendant did not note which was which. The BOD values of the three samples A, B and C were recorded as 20 mg/L, 8 mg/L and 400 mg/L, respectively. Which sample of the water is most polluted? Can you assign the correct label to each, assuming the river water is relatively clean?
One of the free-living anaerobic nitrogen-fixer is _________.
The purpose of biological treatment of waste water is to ______.
In which of the following microbial digestion of organic wastes of sewage takes place?
During tertiary treatment, the bacterial floes sediment in the sedimentation tank, this sediment is called ____________.
After which of the following treatment BOD of the effluent is significantly reduced?
Biochemical Oxygen Demand (BOD) may not be good index for pollution for water bodies receiving effluents from ______.
Removal of suspended, floating, coarse and solid particles in sewage treatment is called ______.
