Question

a) Define sewage.
b) Why secondary treatment is also known as biological treatment?
c) Expand BOD.
d) Why a small portion of activated sludge is pumped back into aeration tanks?
e) What do you understand by the term "Floc"?​

Answer 1

Answer:

a) Define sewage.

b) Why secondary treatment is also known as biological treatment?

c) Expand BOD.

d) Why a small portion of activated sludge is pumped back into aeration tanks?

e) What do you understand by the term "Floc"?

Answer 2

B) Secondary treatment of waste water works on a deeper level than primary level.It is called as biological treatment because it is designed to substantially degrade the biological content of the waste through aerobic biological processes.

This step removes the dissolved organic matter by the use of biological agents.......

C) BOD-Biological Oxygen Demand......

D) A small part of the activated sludge is pumped back into the aeration tanks to serve as inoculam.

when we add a small amount this activated sludge in aeration tank, in presence of oxygen they start multiplying and increase in number to digest organic matter.

E) Floc is a flocculent mass formed in a fluid through precipitation or aggregation of suspended particles. Gentle mixing brings smaller clumps of particles together to form larger groups called FLOC.....

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