Thermal mineralization behavior of PFOA, PFHxA, and PFOS during reactivation of granular activated carbon (GAC) in nitrogen atmosphere.

摘要: Waste disposal site is one of the important sinks chemicals. A significant amount perfluoroalkyl and polyfluoroalkyl substances (PFASs) such as perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS), perfluorohexanoic (PFHxA) have been brought into it. Because their aqueous solubility, PFASs are released to landfill effluent waters, from which efficiently collected by adsorption technique using granular activated carbon (GAC). The exhausted GAC reactivated heating processes. mineralization during reactivation process was studied. Being thermally treated in N2 atmosphere, recovery rate mineralized fluorine PFC homologues including short-chained perfluorocarboxylic acids determined. If reagent form PFOA, PFHxA, PFOS were at 700 °C, less than 30, 46, 72 %, respectively. increased 51, 74, 70 %, if adsorbed onto advance; moreover, addition excess sodium hydroxide (NaOH) improved 91, 90 %. Residual PFAS homologue 1 % original amount. Steamed condition did not affect destruction. role suppress volatile release thermal ambient, whereas NaOH enhanced destruction retained on surface. Comparing fluorine, degradability considered be higher PFOA PFHxA. Whole mass balance missing 9~26 % initial suggested formation some organofluoro compounds beyond analytical coverage.