California Wastewater Operator Exam, Sludge Digestion and Solids Handling: all 23 questions

All questions from the Sludge Digestion and Solids Handling section for California Wastewater Operator Exam, each with the correct answer.

• 6001The main purpose of anaerobic sludge digestion is to
• 6002The typical operating temperature of a mesophilic digester is
• 6003The two groups of bacteria in anaerobic digestion are
• 6004Which condition is the most likely sign of an upset digester?
• 6005A steadily rising volatile acids to alkalinity ratio in an anaerobic digester is mainly a warning of
• 6006A digester that is sour can be corrected by
• 6007Digester gas is normally composed of about
• 6008How should sludge be fed to a digester to keep it stable?
• 6009Under 40 CFR Part 503 Appendix B, anaerobic digestion counts as a Process to Significantly Reduce Pathogens at 35 to 55 degrees C when the mean cell residence time is at least
• 6010Percent volatile solids reduction in a digester is a measure of
• 6011Digester supernatant is returned to the plant headworks. This practice can cause
• 6012Sludge drying beds work by
• 6013Which weather condition will interfere with the use of sludge drying beds?
• 6014A belt filter press is used to
• 6015Polymer is added to sludge before dewatering to
• 6016Gravity thickening of primary sludge is mainly used to
• 6017Waste activated sludge is often thickened by
• 6018What is the best way to prevent odors when handling dewatered sludge?
• 6019The land application of biosolids is regulated mainly to protect
• 6020Class B biosolids must meet requirements for
• 6021Digester mixing is important because it
• 6022The safe way to inspect a digester gas safety device such as a pressure relief valve is
• 6023Scum accumulation in a digester can be reduced by

More topics

• Safety and Hazards26 questions
• Sampling, Laboratory Analysis and Wastewater Characteristics30 questions
• Preliminary and Primary Treatment23 questions
• Secondary Treatment (Activated Sludge, Trickling Filters, RBC)31 questions
• Stabilization Ponds16 questions
• Disinfection and Dechlorination20 questions
• Regulations, Classification and Operator Certification29 questions
• Process Math and Unit Conversions36 questions