1. Operators need to take special precautions against high _ levels when working near blowers.
d. Oil and grease
2. A composite sample provides _.
a. Representative information for given flow or time intervals
b. Information on a waste stream’s DO profile
c. Information on a mixture of different waste streams
d. Instantaneous information on a waste stream
3. Before working on a clogged comminutor, be sure the unit is _.
a. Adequately lit
b. Shut down
d. Turned off, locked and tagged
4. BOD in wastewater is the measurement of the amount of oxygen required _.
a. To produce an equilibrium between wastewater and atmospheric oxygen
b. For the oxidation of sulfites and sulfates
c. To chemically combine with the inorganic matter present
d. For the stabilization of decomposable organic matter by aerobic bacterial action
5. Axial flow is a type of _ pump.
c. Positive displacement