Abstract
Mineralization of a fluorotelomer surfactant containing a C6F13 end-group (FSC), in hot and superheated water was studied. The process was optimized by variation of parameters such as temperature and the presence or absence of O2, Ar, KMnO4 and K2S2O8. Treatment of FSC with a combination of KMnO4 and O2 efficiently decomposed the surfactant to F−, SO42−, and CO2. Specifically, when aqueous FSC (34.8 μmol) and KMnO4 (0.50 mmol) were reacted at 350 °C for 18 h under O2 (13.6 mmol), the F−, CO2, and SO42− yields reached 82, 84, and 97%, respectively, that is, most of fluorine, carbon, and sulfur atoms were mineralized. 1H-Perfluoroalkanes (CnF2n+1H, n = 1–6) were detected as minor products in the gas phase, in amounts that decreased with increasing reaction time. Taken together, these major and minor products accounted for 96% of the fluorine, 97% of the sulfur, and 91% of the carbon atoms in the initial FSC. The in situ formed MnO2 dominantly acted as the oxidizing agent for the mineralization of FSC.