High concentrations of the main components in Scotchgard™ fabric protector products (pre-2002 and post-2002; side-chain fluorinated polymer surfactants, S1 and S2, respectively) were detected in biosolids samples from twenty pan-Canadian wastewater treatment plants (WWTPs). Based on mass spectrometric analysis, S1 and S2 can be named as side-chain perfluorooctane sulfonamide-urethane polymer and side-chain perfluorobutane sulfonamide-urethane polymer, respectively. S1 (with C8F17 side-chain) concentrations ranged from 1.08–105 ng/g d.w. and S2 (with C4F9 side-chain) concentrations ranged from 37.5–2051 ng/g d.w., which were much higher than that of other commonly monitored perfluoroalkyl substances (PFAS). S1 and S2 concentrations were significantly correlated (p < 0.001; r2 = 0.6142) indicating similar source origins. A negative linear correlation was observed (p < 0.05) between concentrations of S1 (or S2) with the volume of WWTP treated wastewater per day per person (m3/person/day). The total concentration of 22 other PFAS ranged from 4.93 to 92.6 ng/g d.w., and approximately thirty times lower than S1 and S2 concentrations. The calculated elemental fluorine concentrations of ƩFS1&S2 were generally much higher than the sum of the other PFAS. PFAS concentrations in biosolids are likely underestimated without consideration of S1 and S2.

Additional Metadata
Keywords Biosolids, Perfluoroalkyl substances, PFAS, Side-chain fluorinated polymer surfactants, Sludge, Wastewater treatment plants
Persistent URL dx.doi.org/10.1016/j.jhazmat.2020.122044
Journal Journal of Hazardous Materials
Letcher, R.J, Chu, S. (Shaogang), & Smyth, S.-A. (Shirley-Anne). (2020). Side-chain fluorinated polymer surfactants in biosolids from wastewater treatment plants. Journal of Hazardous Materials, 388. doi:10.1016/j.jhazmat.2020.122044