What is sludge ?

(a) What is a slag ? (b) What is meant by the term 'Pyrometallurgy' ?

What is a null vector ? What is its use ?

What is a wave ? What are elastic waves ?

What is pedigree analysis? What are the symbols used in such an analysis?

What is activated sludge ?

What happens to activated sludge?

Study the given differences between primary sludge and activated sludge and select the incorrect ones. Primary Sludge Activated sludge (i) It is sludge formed during primary sewage treatment. It is sludge formed during secondary sewage treatment. (ii) It possesses flocs of decomposer microbes. It does not possess flocs of decomposer microbes. (iii) It does not require aeration. Formation of activated sludge requires aeration. (iv) A lot of decomposition occurs during formation of primary sludge. Very little decomposition occurs during formation of activated sludge.

Which of the following is True/false A small part of activated sludge is pumped into large tank called anaerobic sludge digesters.

Read the following statements about activated sludge. a. It is the effluent passed from anaerobic digester to the settling tank. b. A small part of activated sludge is pumped into large tanks called anaerobic sludge digesters. c. A small part of activated sludge is pumped back Into the aeration tank to serve as inoculum. Which of the above statements are incorrect?

Name the bacteria found in sludge of sewage treatment.