WASTEWATER
By Rick LallishWhat is the main problem found when aerobically digesting primary sludge?A. Increased amounts of endogenous respirationB. To maintain DO levels, more air is requiredC. Loss of microorganism growth required for endogenous respirationD. Primary sludge should never be fed to an aerobic digesterAnswer: B. Primary sludge can be used in aerobic digesters, although secondary sludge is more commonly used. The use of primary sludge, due to an increase of organics (food), will increase the microorganism population until the food source is consumed. Then endogenous respiration will begin. The length of time that aerobic digestion requires will still allow for this to occur. But,
