WASTEWATER TREATMENT OPERATOR CERTIFICATION TEST #1 2023 QUESTIONS AND ANSWERS ALREADY PASSED A+

What is the methane content in a properly operation anaerobic digester? A) 30 to 35% by volume B) 1 to 2% by volume C) 65 to 70% by volume D) 15 to 20% by volume - CORRECT ANSWER C) 65 to 70% by volume (v.2 pg 158) What will the addition of chlorine gas do to the pH of wastewater? A) Moderately increase pH B) pH will not be affected C) Significantly increase the pH D) Decrease the pH - CORRECT ANSWER D) Decrease the pH (v.1 pg 349- 350) What is the purpose of a Parshall flume? A) measure turbidity B) measure flowrate C) measure settling rate D) measure solids content - CORRECT ANSWER B) measure flowrate (v.1 pg 43) What is the typical removal efficiency of settable solids in a primary clarifier? A) 95 to 99% B) 40 to 60% C) 20 to 50% D) 10 to 15% - CORRECT ANSWER A) 95 to 99% (v.1 pg 129) Which of the following is true about pumping scum from a primary clarifier?