화학공학소재연구정보센터
Journal of Colloid and Interface Science, Vol.434, 59-64, 2014
Removal of perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) from water by coagulation: Mechanisms and influencing factors
In this study, alum (Al-2(SO4)(3).18H(2)O), ferric chloride (FeCl(3 center dot)6H(2)O) and polyaluminium chloride (PACl) were used to remove perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) from water. The influencing factors, including pH and natural organic matter (NOM), were investigated. A positive correlation was found between the size of the flocs and the removal efficiency of PFOX (X = S and A). The removal ratios of PFOS and PFOA were 32% and similar to 12%, respectively, when 50 mg/L of FeCl3 center dot 6H(2)O was added as the coagulant at the initial pH. Coagulation achieved high removal ratios for PFOX under acidic conditions (similar to 47.6% and 94.7% for PFOA and PFOS at pH 4, respectively). In addition, increasing NOM concentrations decreased the removal rates of PFOX because of the existence of competitive adsorption between NOM molecules and PFOX on the surface of the coagulants and flocs. The combination of adsorption by powdered activated carbon (PAC) and coagulation increased the removal ratios up to >90% for PFOX at the initial concentration of I mg/L, implying that the adsorption enhanced coagulation. Meantime, the experiments with natural water showed that coagulation is a feasible method to remove PFOS and PFOA from surface water. (C) 2014 Elsevier Inc. All rights reserved.