9.
Septic conditions are avoided in the lower part of the lmhoff tank by:
a Frequently removing scum.
b. Frequently removing of sludge.
c. Maintaining a constant rate of flow through the tank.
d. Preventing bubbles from rising through the upper (settling) compartment
because of the conFigureuration of the tank.
e. None of the above is correct.
10. Sludge of proper consistency for removal may be recognized by:
a.
Odor.
b.
Taste.
c.
Appearance.
d.
Test results.
e.
AlI of the above.
11. Name one accomplishment when aerobic processes are employed during
secondary wastewater treatment?
a.
Solids are removed by chemical action.
b.
c.
Organic matter is settled out by plain sedimentation.
d.
Solids are converted by biomedical action into stable substances, which
may then be removed by sedimentation.
MD0161
2-57