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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 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?
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.
Which of the following is TRUE about primary treatment?
Which of the following occurs during secondary treatment?
During tertiary treatment, the bacterial floes sediment in the sedimentation tank, this sediment is called ____________.
Which of the following process is a part of preliminary treatment of sewage?
Nitrogen fixation by organisms requires conditions that are:
Why are flocs important in biological treatment of waste water?
Ganga has recently been declared the national river. Discuss the implication with respect to pollution of this river.
