American Water College Published on Mar 26, 2012 http://americanwatercollege.org
This question comes from the California Wastewater grade 3 certification exam sample questions that can be found here: http://www.swrcb.ca.gov/water_issues/...
The problem reads: In an attempt to correct a filamentous growth in an activated sludge process, you want to inject chlorine into the RAS flow stream at the dosage of 2.5 pounds of chlorine per 1000 pounds of return activated sludge suspended solids. Show the calculations to find the proper chlorinator feed setting (in pounds of chlorine per day), given the following information:
Average Plant Flow Rate 9.0 MGD - MLSS Conc. 2850 mg/L RAS Flow Rate 3.3 MGD - MLVSS Conc. 2600 mg/L WAS Flow Rate to DAF 1.2 MGD - RAS Conc. 8500 mg