TY - JOUR
T1 - Effect of temperature on oxidative transformation of perfluorooctanoic acid (PFOA) by persulfate activation in water
AU - Liu, C. S.
AU - Higgins, C. P.
AU - Wang, F.
AU - Shih, K.
N1 - Funding Information:
We acknowledge the funding for this research provided by Hong Kong Research Grants Council (Research Fund Scheme HKU 716809E), Hong Kong University Grants Council (Special Equipment Grant SEG_HKU10), and the National Natural Science Foundation of China (40801086). The authors are thankful to Ms. Vicky Fung, Dr. Bing Li, and Mr. Ke Yu for assisting with the UPLC/MS/MS analysis.
PY - 2012/5/3
Y1 - 2012/5/3
N2 - Perfluorooctanoic acid (PFOA) is an emerging environmental pollutant attracting significant attention due to its global distribution, high persistence, and bioaccumulation properties. In this study, the degradation of aqueous PFOA at different temperatures was examined using heat-activated persulfate. Using this approach, 93.5% of PFOA was degraded after 30 h at 85 °C with 43.6% of F - yield, and the shorter chain length compounds (PFHpA (C 6F 13COOH), PFHxA (C 5F 11COOH), PFPeA (C 4F 9COOH), and PFBA (C 3F 7COOH)) were observed as degradation intermediates. The sequential degradation mechanism of losing one CF 2 unit from PFOA and its intermediates on a step-by-step basis were observed. Controlled temperature kinetics studies yielded an activation energy of approximately 60 kJ/mol for the degradation of PFOA by heat-activated persulfate. However, at elevated temperatures, excess persulfate is needed for efficient PFOA degradation, presumably due to more intensive SO4- scavenging. Lower reaction pH was generally found to inhibit PFOA degradation, presumably due to the more prevalent radical-to-radical interactions.
AB - Perfluorooctanoic acid (PFOA) is an emerging environmental pollutant attracting significant attention due to its global distribution, high persistence, and bioaccumulation properties. In this study, the degradation of aqueous PFOA at different temperatures was examined using heat-activated persulfate. Using this approach, 93.5% of PFOA was degraded after 30 h at 85 °C with 43.6% of F - yield, and the shorter chain length compounds (PFHpA (C 6F 13COOH), PFHxA (C 5F 11COOH), PFPeA (C 4F 9COOH), and PFBA (C 3F 7COOH)) were observed as degradation intermediates. The sequential degradation mechanism of losing one CF 2 unit from PFOA and its intermediates on a step-by-step basis were observed. Controlled temperature kinetics studies yielded an activation energy of approximately 60 kJ/mol for the degradation of PFOA by heat-activated persulfate. However, at elevated temperatures, excess persulfate is needed for efficient PFOA degradation, presumably due to more intensive SO4- scavenging. Lower reaction pH was generally found to inhibit PFOA degradation, presumably due to the more prevalent radical-to-radical interactions.
KW - Degradation mechanism
KW - Oxidative degradation
KW - Perfluorochemicals
KW - S O
KW - Sulfate radical
UR - http://www.scopus.com/inward/record.url?scp=84860229636&partnerID=8YFLogxK
U2 - 10.1016/j.seppur.2011.09.047
DO - 10.1016/j.seppur.2011.09.047
M3 - Journal article
AN - SCOPUS:84860229636
SN - 1383-5866
VL - 91
SP - 46
EP - 51
JO - Separation and Purification Technology
JF - Separation and Purification Technology
ER -