1. Chlorella, Chlamydomanas, and Euglena are common _ found in wastewater lagoons.
a. bacteria
b. alage
c. fish
d. water fowl

2. Methane fermentation in wastewater lagoons consists of _.
a. the conversion of organic material to methane by bacteria
b. the reduction 5 day BOD by coliform bacteria
c. the conversion of algae into methane by ultraviolet light
d. the conversion of inorganic material into organic material and methane gas by bacteria

3. An operator finds excessive organic material in the grit removed from the grit chamber. How can this situation be corrected?
a. increase the velocity by reducing the number of channels in use
b. decrease the velocity by increasing the number of channels in use
c. cleaning the grit change more frequently

4. Digester gas may be used as a fuel when the methane content exceeds _ %.
a. 35
b. 50
c. 65
d. 75

5. The best way to control excessive foaming during start up of a digester i to _.
a. add water to the tank
b. allow the digester content to cool slightly
c. increase the feed rate
d. stir gently to release excess gas

Answers:

1. a
2. a
3. c
4. d
5. d