Treatment Plant Operator Exam Study Guide Answers

What type of activated sludge treatment process is used when the influent is considered nutrient deficient? The answer is A, the Kraus process. The Kraus process is when the wastewater is nutrient deficient or has a greater ratio of carbonaceous to nitrogenous materials. This is usually found in dairy or cannery operations. It is a modification of a conventional activated sludge process and uses a portion of the anaerobic digester supernatant to supplement the nutrients needed for the activated sludge process. Other benefits of the Kraus process include increased sludge settleability and a ready supply of organisms. A water softener is 5