Ozone is an increasingly popular oxidant and disinfectant for the treatment of drinking water and the polishing of wastewater. Typically, ozonation is combined with a subsequent biofiltration step that utilizes beneficial bacterial communities to remove partially oxidized contaminants and assimiable organic matter that is formed by ozone. To better understand the processes occuring during such treatment schemes a small-scale ozone/sand filtration system based on electrolytic ozone production was designed. Ozone is produced continuously at very small amounts and enables in this way continuous laboratory experiments with biologically active sandfilters. The fate of a few well-known trace contaminants was investigated, including NDMA precursor compounds, acesulfame, carbamazepine, diclofenac and fluoxetine. LC-MS was used as the main analytical tool. As expected, during ozonation a degradation of parental compounds with simultanteous formation of typical transformation products could be observed. Subsequent sandfiltration passage of the ozonated water led to a decline in most transformation products via bacterial degradation. The initial investigation has shown that the developed system is easy to build and maintain. The set-up can serve as a flexible tool to predict the fate of trace contaminants in larger scale treatment facilities using combined oxidation/biofiltration treatment.

Lab-scale continuous ozonation combined with biofiltration to understand the fate of trace contaminants during slow sand filtration and soil aquifer treatment

255th National Meeting (2018)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.