Advancing the treatment of primary influent and effluent wastewater during wet weather flow by single versus powdered activated carbon-catalyzed ozonation for the removal of trace organic compounds

Abstract

For the first time, single and PAC-catalyzed ozonation were explored for the wastewater treatment during wet weather flow in a prompt and efficient process. The effect of varying the ozone (O3) specific dose on the removal of micropollutants (MPs) was first investigated with a mixture of pharmaceuticals, herbicides and perfluorinated compounds in clean water. Most MPs showed higher affinity towards catalytic ozonation. Carbamazepine and Atrazine were found to be good surrogates for fast and slow reacting compounds, respectively. Applying single or PAC-catalyzed ozonation for 1 min only after coagulation was more efficient than applying them simultaneously. PAC-catalyzed ozonation was more efficient for the removal of organics and O3-resistant MPs. Both single and PAC-catalyzed ozonation achieved 4 log removal of E. coli, reduced the acute and genetic toxicity, and estrogenic activity of the wastewater. A detailed cost analysis revealed that applying single ozonation after coagulation costs between 0.06 and 0.32 $/m3 while applying PAC-catalyzed ozonation costs between 0.32 and 0.63 $/m3 for a flow rate between 100 and 600 MLD. Through a comprehensive performance assessment, PAC-catalyzed ozonation was deemed superior with one drawback related to the disposal of PAC.