CA GRADE 2 WASTEWATER TREATMENT OPERATOR PRACTICE EXAM 1 2023 QUESTIONS AND ANSWERS ALREADY PASSED A+

What is the methane content in a properly operating anaerobic digester? - CORRECT ANS 65 to 70% by volume What will the addition of chlorine gas do to the pH of wastewater? - CORRECT ANS decrease the pH What is the purpose of a Parshall Flume? - CORRECT ANS Measure the flow rate What is the typical removal efficency of settleable solids in a primary clarifier? - CORRECT ANS 95 to 99% Which of the follwing is true about pumoing scum from a primary clarifier? - CORRECT ANS scum causes more piping problems than other substances pumped at a wastewater treatment plant What might cause thick billows of white sudsy foam in the aeration tank? - CORRECT ANS MLSS is too low What does the M in F/M ratio represent? - CORRECT ANS The mixed liquor volatile suspended solids in the aeration tank In general, how will warmer temp affect the settling rate of solids in a clarifer? - CORRECT ANS Increase the settling rate What could happen if the digester gas is mixed with air(85 to 95% by volume)? - CORRECT ANS Cause an explosion How will algae impact the chlorine demand in the pond effluent? - CORRECT ANS increase the chlorine demand Which of the following is true about a positive displacement pump? - CORRECT ANS it must never be started with the discharge valve closed What is true about the F/M ratio? - CORRECT ANS the volume of the secondary clarifier is not needed to determine the f/m ratio Which of the following is one of the basic rules of lab work? - CORRECT ANS never pipet hazardous material with your mouth, even if the pipet has been sterialized What is the recirculation ratio for a trickling filter? - CORRECT ANS Qr/Q Which of the following is true about COD and BOD? - CORRECT ANS they are indirect measurements of the organic content in the influent What is the purpose of the grit channel? - CORRECT ANS remove heavy inorganic waste Which of the following is true about the extended aeration process? - CORRECT ANS it does not produce as much waste sludge as other processes What is the correct formula for solids in raw wastewater? - CORRECT ANS Non settleable solids + settleable solids = total suspended solids What is freeboard in a waste stabilization pond? - CORRECT ANS the vertical distance from normal water surface to the top of the levee What is one of the requirements for a BOD test? - CORRECT ANS The BOD bottle should be completely filled to the top What should be scheduled every 3 months for a flamer arrester in an anaerobic digester? - CORRECT ANS maintenance