Ozone Enhanced Biological Activated Carbon Filtration and its Effect on Organic Matter Removal, and in Particular on AOC Reduction

Abstract

Ozonation prior to GAC filtration is evaluated in relation to organic matter removal, and in particular to AOC (assimilable organic carbon) reduction. In terms of TOC removal, experimental results on pilot plant scale showed an increase of filter service time with about 60 % to 65 %. A dosage higher than 2 mg ozone/1 had no additional effect. The extent to which this increase of service time was predominantly due to enhanced biological activity or to long term cumulative slow adsorption is not yet clear. Ozonation caused a very significant increase of AOC. This increase was a function of the applied ozone dosage. First experimental results suggested a relation between ozonation and an early “breakthrough” of AOC with GAC filters fed with ozonated water.