Control of Contaminants of Emerging Concern (CEC) During Pilot Scale Advanced Oxidation Processes (AOPs) for Water Reuse

This study assessed the control of contaminants of emerging concern (CEC) during AOPs (advanced oxidation process) pilo” plant installed downstream of two different wastewater treatment plants (WWTPs) designed for water reuse. UV- and ozone-based AOPs were investigated for the removal of CEC present in real wastewater. The removal efficiency (RE) of selected CEC from WWTP-1 and WWTP-2 effluents was discussed considering their photo-susceptibility, reactivity with •OH and ozone (O3). In general, CEC showed REs between ~ 60% and 100% during UV/H2O2 process in WWTP-1 effluent, and between ~ 0% and 100% during O3 and O3/H2O2 processes in WWTP-1 and WWTP-2 effluents. Fluorescence spectroscopy was performed on collected samples in order to obtain excitation/emission matrices (EEM). Peak-picking method was used for EEMs interpretation. Linear predictive models of CEC removal efficiency were developed using the removal of EEM fluorescence peaks as surrogate parameter. Particularly, the removal of the fluorescence peak corresponding to the microbial/tryptophan-like region was found highly correlated with the removal of micropollutants, suggesting that this fluorescence peak is suitable for near real-time monitoring of a wide range of micropollutants having different concentrations, physical-chemical characteristics, and reactivity.