ABC Wastewater Level 3 - Activated Sludge (Questions + Answers) Verified 100% Correct!!

Performance problems in the activated sludge process can be caused by ____________. A. Poor solids dewatering B. Inadequate chlorination of effluent C. Consistent influent characteristics D. Insufficient operator training - Answer-D. Insufficient operator training Solids that float to the surface of the clarifier are referred to as ____________. A. Mixed liquor B. Film C. Residual solids D. Scum - Answer-D. Scum Solids that settle to the bottom of clarifiers and are removed from the process are referred to as ___________. A. RAS B. WAS C. TSS D. Total residual chlorine - Answer-B. WAS Large amounts of filamentous bacteria can improve floc structure and speed the settling of the mixed liquor. A. True B. False - Answer-B. False Protozoans are much more abundant than bacteria in activated sludge. A. TrueB. False - Answer-B. False Under normal conditions, fungi (yeast and molds) are present in activated sludge processes. A. True B. False - Answer-B. False Algae are microscopic plants that can become a nuisance in clarifier launders. A. True B. False - Answer-A. True Which of the following does not result from a pH imbalance in an activated sludge process? A. Power consumption B. Inability to maintain a healthy biomass C. Damage to process equipment D. Increased cost because of chemical addition - Answer-A. Power consumption Because of industrial flows and the nitrification process, pH imbalances may become a concern for activated sludge processes if sufficient __________ is not present. A. TSS B. Alkalinity C. Ammonia D. BOD - Answer-B. Alkalinity Which of the following is NOT a phase of a typical sequencing batch reactor treatment cycle? A. Filter B. Fill C. Decant D. Settle - Answer-A. Filter