What Really Makes Activated Sludge Secondary Clarifiers Work?

The wastewater treatment profession has long studied activated sludge secondary clarifier design. Performance improvements of the next “optimal design” are less and less significant indicating a path of diminishing return. Through years of experience in research, engineering, and operations, the author argues that the greatest advancement in secondary clarifier performance available today lies in improving the quality of sludge entering secondary clarifiers. Sludge quality, in turn, is primarily the responsibility of operators, not so much design engineers and manufacturers. The author goes on to suggest that improving sludge quality will be accomplished through a refresh—retooling even—of the way in which operators are educated, trained, and certified.