1. Less heat is required to maintain the temperature in a digester where thick sludge is pumped than one where relatively thin sludge is pumped to the digester.
a. true
b. false

2. A scum blanket in a digester may be broken up by vigorously mixing the digester contents.
a. true
b. false

3. A stuck digester means that the cover has tilted to one side and the edge has become lodged in the annular space.
a. true
b. false

4. Ponds with long detention times (longer than 20 days) usually produce a better effluent with a shorter detention time.
a. true
b. false

5. A polishing pond is a form of a tertiary treatment.
a. true
b. false

Answers:

1. a
2. b
3. b
4. b
5. a