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 micro-contaminant (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 m(3) 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 O-3 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.