Biodegradation Property of 8:2 Fluorotelomer Alcohol (8:2 FTOH) under Aerobic/Anoxic/Anaerobic Conditions

Abstract

The objective of present research was to clarify the effects of environment conditions of oxygen on FTOHs biodegradation property. The lab-scale batch tests of 8:2 FTOH biodegradation under aerobic/anoxic/anaerobic conditions were conducted with acclimated activated sludge collected from an industrial wastewater treatment plant. The results revealed that 8:2 FTOH biodegradation property differed in aerobic/anoxic/anaerobic conditions. The first-order rate constants of 8:2 FTOH were 6.10 × 10 −2 , 1.24 × 10 −2 and 5.81 × 10 −3 [L·g-SS -1 ·h -1 ] under aerobic/anoxic/anaerobic conditions, respectively. Within 24 hours, the transformed PFCAs (C4 − C9) moles to the applied 8:2 FTOH were 11.12%, 0.46% and 3.39% under aerobic/anoxic/anaerobic conditions, respectively. Under aerobic condition, PFCAs were remarkably generated. The increased moles of PFOA and PFHpA occupied the applied 8:2 FTOH as 7.87% and 1.29%, respectively. Moreover, the increasing tendency of PFCAs was maintained within 24 hours. The anoxic and anaerobic generation of PFCAs, besides PFOA, were not significant.

Biotransformation of 8:2 Fluorotelomer Alcohol in Soil from Aqueous Film-Forming Foams (AFFFs)-Impacted Sites under Nitrate-, Sulfate-, and Iron-Reducing Conditions

“…However, a significant increase (p < 0.05) was only observed for PFOA after comparing the concentrations of these PFCAs in ED and NA treatments to positive controls (Figure S5), demonstrating that PFOA was formed during 8:2 FTOH biotransformation under nitrate-reducing conditions. Although the concentrations of other PFCAs including perfluorobutanoic acid (PFBA), perfluoropentanoic acid (PFPeA), perfluorohexanoic acid (PFHxA), and perfluoroheptanoic acid (PFHpA) in livespiked treatments were not significantly different from those in positive controls, some PFCAs might be biotransformation products as reported previously under both oxic 23,32 and anoxic conditions 35,46 but with yields that were too low to be distinguished from the background levels in Loring soil. After subtracting the PFOA mass in positive controls at each sampling point, the molar yields of PFOA in both ED and NA treatments continued to increase during the incubations, reaching 6.4 ± 0.5 and 4.0 ± 0.4 mol % of the initially applied 8:2 FTOH at the end of incubation, respectively (Figure 1B,C).…”

Structure-Specific Aerobic Defluorination of Short-Chain Fluorinated Carboxylic Acids by Activated Sludge Communities

“…Thus far, tremendous efforts have been invested in understanding the environmental fate and transport of FCAs using microcosms and microbial isolates. ,,, −, − In Table , we summarized the aerobic defluorination reported in the literature and this study for C 2 –C 10 FCAs and the alcohol precursors oxidizable to carboxylic acids. In the table, all defluorinated structures share a common feature: a functional group subject to enzymatic defluorination or nondefluorinating reactions that form unstable intermediates with fluoroalcohol moieties causing spontaneous C–F cleavage.…”

Remediation of poly- and perfluoroalkyl substances (PFAS) contaminated soils – To mobilize or to immobilize or to degrade?

“…FTOHs biodegradation rates and pathways differed among aerobic/anoxic/anaerobic conditions, with the first-order rate constants in the following decreasing order: aerobic > anoxic > anaerobic conditions (Yu et al, 2016). The anaerobic biodegradation of FTOH was found inefficient to produce PFCAs, but might form polyfluorinated acids (Zhang et al, 2013b).…”