Reversing clogging in Imhoff tanks by catalyzed hydrogen peroxide treatment

Abstract

One of the most frequently encountered operational problems with Imhoff tanks is filter media clogging. Traditionally, the restoration procedure is to remove the clogged rock media and replace them with clean material. This is costly and may require the facility to close for a time. Recently, an innovative approach has been tested at lab- and full-scale. It consisted of aggressive oxidation and segregation of the clogged solids, using catalyzed hydrogen peroxide. The results indicate that, after treatment, clogging was substantially reduced. The outcomes of the lab- and full-scale studies are discussed in this paper.