Assessing Ozonation as Pretreatment for Granular Activated Carbon Filtration

摘要

Water treatment schemes comprising combinations of low dose ozonation, GAC filtration, slow sand filtration and hyperfiltration, and their effeft on pesticide removal, are investigated on a pilot scale usign Rhine water pretreated with coagulation, sedimentation andrapid filtration. The research is part of a broader range of activities concerning the future capacity extension of the Water Supply Amsterdam. teh role of ozonation is to achieve a certai ndegree of disinfection (i.e. mainly virus inactivation), while avoiding unacceptable bromate formation. Furthermore, ozonation is expected to increase biodegradability of Natural Oganic Matter (NOM), decrease its adsorbability, and yield partial pesticide oxidation to more biodegradable by-products. As a result, ozonation is expected to delay the breakthrough of pesticides and other micropollutants during GAC filtration. Teh later decreases the required frequency of GAC regenration and, therefore, reduces opertional costs.