Biodegradation behavior of ozonated natural organic matter in sand filters

Abstract

In this study, an ozonated natural organic matter (NOM) solution was used as a substrate. The NOM was isolated from a groundwater in Germany using ion-exchange resins. The ozone dose was 0.35 mg O3/mg DOC (dissolved organic carbon). Previously bioacclimated sand was used as filter media and biomass source and was homogeneously distributed in the filter prior to each run. When expressed in terms of the empty bed contact time (EBCT), the results showed that filter velocity in the range of 1.5 to 15 m/hr had no impact on susbstrate removal. This implies that substrate utilization, not external mass transfer, is the rate limiting step for substrate removal in drinking water biofilters.