ABC Wastewater Level 3 - General Exam Questions Rated 100% Correct!!

ABC Wastewater Level 3 -General Turbidity in wastewater is caused by A. color B. dissolved calcium C. hardness D. finely divided suspended material - Answer -D. finely divided suspended material The gas most commonly associated with septic wastewater is A. carbon dioxide B. carbon monoxide C. hydrogen sulfide D. methane - Answer -C. hydrogen sulfide How many cubic meters per second in 10 MGD? A. 0.44 B. 1.44 C. 4.73 D. 24.62 - Answer -A. 0.44 Mechanical ventilation of a lift station is required to A. lower temperatures to reduce proportion of hydrogen sulfide B. reduce chlorine demand C. reduce corrosion D. increase DO in raw wastewater - Answer -C. reduce corrosion A wet well probe is usually used for ________ determination(s) of level. A. approximate B. dual point C. continuous D. single point - Answer -D. single point A pump is delivering at less than the expected rate of discharge. Which of the causes listed below is incorrect? A. speed of motor too low B. pump not primed C. impeller clogged D. discharge head too low - Answer -D. discharge head too low Metal pipes often fail because of A. back siphonage B. browning movement C. galvanic action D. reverse osmosis - Answer -C. galvanic action When a fire hydrant is operated, it should be A. just opened enough to have a flow B. opened fully C. opened halfway D. regulated to flow required - Answer -B. opened fully If the pump bearings on horizontal centrifugal pumps are over lubricated, the most important effect is that the extra lubricant A. will result in smoother and more efficient operation of the pump B. will not make any difference in the operation of the pump C. will be wasted D. shaft or shaft sleeve will be damaged - Answer -D. shaft or shaft sleeve will be damaged If packing is not maintained properly, A. cavitation damage will result B. impeller will corrode C. loss of suction due to air being allowed to enter pump D. shaft or shaft sleeve will be damaged - Answer -C. loss of suction due to air being allowed to enter pump Air flow through a trickling filter when the influent is warmer than the air temperature is A. upward through the filter B. downward through the filter C. inadequate and may require forced air ventilation D. improved by decreasing the recirculation - Answer -A. upward through the filter An active sludge in the aeration tank with an abundant available food supply will have a relatively A. high oxygen uptake and fast settling rate B. high oxygen uptake and slow settling rate C. low oxygen uptake and fast settling rate D. low oxygen uptake and slow settling rate - Answer -B. high oxygen uptake and slow settling rate The reaction of chlorine and ammonia produces a compound which is called A. ammonium chloride B. chloral hydrate C. chloramine D. hydrazine - Answer -C. chloramine A malfunctioning gas chlorination system has normal gas pressure, no feed rate indicated on rotometer, and no injector vacuum. What is the most likely cause of the problem? A. air leak upstream of rotameter B. gas line plugged C. injector clogged D. pressure reducing valve diaphragm ruptured - Answer -C. injector clogged What is the impact of increased viscosity on the effectiveness of mixed media filters? Mixed media filters are A. affected only if temperature also changes B. less effective C. more effective D. not affected - Answer -B. less effective The precipitate in coagulation with alum is aluminum A. bicarbonate B. carbonate C. hydroxide D. sulfate - Answer -C. hydroxide Given the following data, what is the most likely cause of the mechanically cleaned bar screen problem? DATA: Above normal water differential across bar screen Drive motor shaft turning Drive sprocket, chain, rake not moving Less than normal flow on bar screen downstream side Bar screen mode selector in automatic position Normal seasonal flow (influent) coming into bar screen Alarm systems operating normally A. low influent (incoming) level B. raw wastewater pumping units out of service C. sheared pin or disengaged clutch