Occurrence of UV filters, fragrances and organophosphate flame retardants in municipal WWTP effluents and their removal during membrane post-treatment

- Occurrence and removal of selected CECs from urban WWTPs effluents by UF, NF and RO.
- At least 75% removal of fragrances independent of the membrane used.
- The rejection rates of OPFRs strongly depended on membrane process applied.
- Membrane treatment reduced the potential risk in the receiving aquatic environment.

Membrane filtration using ultrafiltration (UF), nanofiltration (NF) or reverse osmosis (RO) membranes was evaluated as an efficient effluent polishing step at municipal wastewater treatment plants (WWTPs) for the removal of selected contaminants of emerging concern and for improvement of water quality according to water reuse requirements. In samples collected at two largest WWTPs in Norway, 12 out of 14 selected personal care products and organophosphate flame retardants (OPFRs) were found above analytical detection limit. The highest concentrations were observed for BP3, OC (UV filters), HHCB, AHTN (fragrances), TCPP and TBP (OPFRs), exceeding the predicted no-effect concentration for BP3 in one sample and AHTN in five samples. Independently of the membrane type used, membrane filtration effectively (>60%) removed BP3, UV-329, OC, HHCB, AHTN and DBPP. However, UF was insufficient (<20%) for removal of DEET, TCPP and TCEP. UF was sufficient to remove 30-50% of COD, 80-95% of TP, up to 30% of TN and NH4, and a min of 2 log reduction of E. coli. Water quality improved further with application of NF and RO. The results indicate that membrane filtration can be effective post-treatment to improve overall water quality and a measure to reduce potential risk in the receiving aquatic environment.