ABSTRACT
This chapter aims to identify and understand mechanisms that underlie the expected beneficial effect of ozonation on the removal of pesticides and other micropollutants by Granular Activated Carbon (GAC) filtration. The main purpose was to verify the expectation that the removal of atrazine in GAC filters is improved due to ozone-induced oxidation of Background Organic Matter (BOM) from pretreated Rhine River water. BOM refers to the organic matter in the influent of GAC filters other than the target compounds that need to be removed. The effect of enhanced biodegradation of ozonated BOM, which is also expected to reduce the competitive adsorption of BOM, was not investigated. Several pilot plant experiments were done to assess the range of ozone doses that may be applied when the role of ozonation is to provide an essential contribution to the disinfection of water and to promote biodegradation in GAC filters, while avoiding an unacceptable formation of bromate.
