1. The machine that tears debris after the bar screen is called a _.
2. The principle function of the zoogleal mass on the trickling filter is to _.
a. filter the suspended solids
b. reduce the organic content
c. reduce the nitrogenous BOD
d. control the flow to the following processes
3. When a trickling filter has a recirculation of 0.5 to 1.0, this indicates that the flow of the water over the filter is _ of the flow of the raw wastewater.
e. none of the above
4. What are the four reagents used to prepare a sample before performing a Winkler?
a. alkali iodide, manganese sulfate, starch and sulfuric acid
b. mercuric chloride, manganese sulfate, starch and sulfuric acid
c. borate buffer, phosphoric acid, alkali iodide and starch
d. alkali, iodide, manganese sulfate, starch, and phosphoric acid
5. The BOD incubator needs to be at _ degrees C.