State-of-the-art of the application of ozonation in BENELUX drinking watertreatment

Major objectives for drinking water treatment are microbiological integrity , organic contaminant control and the production of biologically stable wat er. In view of these objectives many BENELUX water supply companies have up graded their treatment plants. In many retrofit plants ozonation has been i mplemented. In ground water treatment eight Dutch and three Belgian plants have been up graded with ozonation for disinfection and to remove manganese, color, tast e and odor and organic micropollutants. Although the primary objective was achieved, regrowth caused five Dutch companies to abandon ozone again and i ntroduce activated carbon use. In surface water treatment, six Dutch and fo ur Belgian plants have installed ozonation for disinfection and organic con taminant control. Assimilable organic compounds produced by ozone enhance b iological activity in the carbon filters or may cause aftergrowth problems. Aftergrowth problems after post ozonation caused three Belgian companies t o abandon ozonation again. Future plans comprise advanced oxidation, i.e. combined use of ozone and hy drogen peroxide for organic contaminant control.