Is the combination of nanofiltration membranes and AOPs for removing microcontaminants cost effective in real municipal wastewater effluents?
The purpose of this work was the economic assessment of different municipal wastewater treatment plant (MWTP) effluent treatment operating strategies based on the combination of nanofiltration (NF) and EDDS-assisted solar photo-Fenton at neutral pH or ozonation at natural pH. The study focused on microcontaminant (MC) removal as evaluated by LC-Qtrap-MS. Direct treatment of MCs in MWTP effluents was compared with their treatment in an NF rejection stream. Costs were estimated based on a flow rate of 1000 m3 per day (365 operating days per year) and over 90% degradation of 35 different MCs. The highest operating costs were related to EDDS and the hydrogen peroxide for photo-Fenton, pumping for NF and O3 generation for ozonation. It was concluded that both photo-Fenton and ozonation applied to NF rejection lowered treatment costs compared to MWTP effluent treatment. Ozonation was the most economical in all cases.