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प्रश्न
Explain the steps involved in preliminary treatment of sewage.
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उत्तर
- Screening: Sewage and waste water contain plenty of suspended, floating materials, coarse, and solid particles, along with dissolved substances. The suspended objects are filtered and removed. This is done in screening chambers. The sewage is passed through screens or net in the chambers. Larger suspended or floating objects are held in the screening chambers. These have to be removed before the biological treatment.
- Grit Chamber: After screening, the filtered sewage is then passed into a series of grit chambers. These chambers contain large stones (pebbles) and brick-ballast. Coarse particles settle down by gravity. Thus, passage of filtered sewage removes much of the coarse particulate matter.
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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?
What is primary treatment of sewage?
After which of the following treatment BOD of the effluent is significantly reduced?
Why do we prefer to call secondary waste water treatment as biological treatment?
In what way anaerobic sludge digestion is important in sewage treatments?
After a significant reduction in the BOD of wastewater, it is passed into a settling tank where bacterial flocs are allowed to sediment. This sediment is called ______.
Removal of suspended, floating, coarse and solid particles in sewage treatment is called ______.
What are 'flocs' in the context of biological wastewater treatment?
What happens to the polluting potential of wastewater as its Biochemical Oxygen Demand (BOD) increases?
