The fate of ten phosphorus ester flame retardants (aryls and alkyls) in activated sludge and advanced oxidation process sewage works was assessed in five sewage works in Spain. Concentrations detected in sewage works inflow ranged from 4 to 150 parts per billion (total of the ten FRs). These results shows that concentration remains at extremely low level.
The chlorinated alkyl FRs (TCEP, TCIPP, TDCPP) were not removed by standard sewage treatment (activated sludge) whereas the aryl FRs (TMPP, EHDP, TEHP and TPHP) were mainly transferred to sewage sludge and were not detectable in the plant discharges. Advanced treatment (ultraviolet/H2O2 peroxide or ozone) proved to be effective in breaking down the non-chlorinated P-FRs detected in wastewater effluent (TNBP, TIBP, TBOEP) but not the chlorinated alkyls.
“Can activated sludge treatments and advanced oxidation processes remove organophosphorus flame retardants?” J. Cristale et al., Environmental Research 144 (2016) 11-18