Simultaneous ozone and granular activated carbon for advanced treatment of micropollutants in municipal wastewater effluent.

The main objective of this study was to compare the efficacy of ozone (O) and O with granular activated carbon (GAC) (O/GAC) at pilot-scale for the enhanced removal of micropollutants (MPs) from wastewater effluent. The results revealed enhanced removal of tris (2-carboxylethyl) phosphine (TCEP), sucralose, and meprobamate during the O/GAC treatment experiments compared to the sum of their removal during isolated ozonation and GAC adsorption experiments. The long-term O/GAC experiment showed the promotive effect of GAC substantially decreased after 20 h of O exposure. This decreased performance correlates with changes to GAC surface properties caused by O. After 6 h of operation, O initially led to an increase in Brunauer-Emmett-Teller (BET) surface area on the GAC improving the elimination level of investigated MPs (except N-nitrosomorpholine (NMOR)). However, after 20 h of exposure, O ultimately caused structural damages to the GAC surface, decreased the BET surface area in the final stages of the experiment, and a 4-fold increase in O:C ratio on the GAC surface was observed due to an increase in surface acidic functional groups caused by O treatment.