QUESTIONS AND ANSWERS 2026
Primary Clarifiers - ANSWERSIn an activated sludge treatment system, primary
treatment processes include the:
Removal of Inorganic material from grit - ANSWERSIn a washing grit remover, the grit
is moved slowly by screw conveyors up an inclined channel in order to?
90% or above - ANSWERSAn efficient primary clarifier is expected to remove ? of the
influent settleable solids.
Adequate DO at surface at all times - ANSWERSProper operation of a facultative pond
system requires that:,
True - ANSWERSThe amount of organic matter removed by a trickling filter is mostly
dependent on the recirculation ratio
Bulking - ANSWERSIn an activated sludge treatment plant, a Sludge Volume Index
(SVI) of 180 would indicate
Reseed The AB, Remove sludge from FC - ANSWERSThe purpose of returning the
solids from the bottom of the clarifier to the aeration tank in the activated sludge process
is to
Free swimmer rotifers stalked ciliates - ANSWERSMicroscopic examination of a good-
settling sludge should show a predominance of:
Dissolved oxygen (DO) or oxygen obtained from food materials such as sulfate or
nitrate - ANSWERSWhen nitrification takes place in the activated sludge process,
facultative bacteria use
Primary clarifiers - ANSWERSIn an activated sludge process, the results of a mixed
liquor settling test indicate that the supernatant of the mixed liquor sample is clear, but
the supernatant of the plant effluent sample is turbid. These test results indicate that the
problem is occurring in the?
Low C02 high Methane - ANSWERSOne indication that an anaerobic digestion facility is
improving would be?
False - ANSWERSThe terms "low rate" and "high rate" when used in reference to the
anaerobic digester refer to the rate of stabilization of the raw sludge?