Microbes in Sewage Treatment

Explanation

(1)Microbes play a vital role in sewage treatment.(2)The sewage treatment includes three processes,viz,.primary treatment.secondary treatment and tertiary treatment.(3)Of these,secondary and tertiary treatment involve the use of microbes.(4)During secondary treatment when the useful aerobic microbes takes place into flocs.The microbes present in flocs consume the organic matter present in the effluent.(5)During tertiary when the BOD of waste water is reduced,it is transferred to settling tank where the bacterial flocs sediment.(6)The sediment present at the bottom of the settling tank is known as activated sludge.(7)Major portion of the activated sludge is pumped into the large tanks called anaerobic sludge digesters where anaerobic bacteria grow and digest the bacteria and fungi present in the sludge.