Department of Environmental Science and Engineering, POPs Research Center, Tsinghua University, Beijing 100084, PR China.
Water Res. 2011 Feb;45(4):1774-80. doi: 10.1016/j.watres.2010.11.029. Epub 2010 Nov 30.
Perfluorooctanoate (PFOA) has been detected in surface water all over the world, and little is known of its removal by coagulation in water treatment plants. In this study, polyaluminium chloride (PACl) was used to remove PFOA from surface water, and the effects of coagulant dose, solution pH, temperature, and initial turbidity on the removal of both PFOA and suspended solids (SS) from water were investigated. Since the SS had high sorption affinity for PFOA, most PFOA was adsorbed on the particles and removed via the SS removal in the coagulation process. PFOA concentrations in aqueous phase decreased with increasing initial turbidity and PACl dose, while they increased with increasing solution pH and temperature. Other perfluorinated compounds (PFCs) with different C-F chain lengths and functional groups were also compared with PFOA. It was proved that hydrophobic interaction played an important role in the adsorption of PFOA on the SS. The addition of powdered activated carbon (PAC) before the coagulation process significantly enhanced the removal efficiency of PFOA in water, and the residual PFOA concentrations in water were less than 1 μg/L after the addition of 1-16 mg/L PAC and subsequent coagulation when the initial PFOA concentrations were in the range of 0.5-3 mg/L.
全氟辛烷酸（PFOA）已在世界各地的地表水 中被检测到，而对于其在水处理厂中的去除方法知之甚少。在本研究中，使用聚合氯化铝（PACl）去除地表水中的 PFOA，并研究了混凝剂剂量、溶液 pH 值、温度和初始浊度对 PFOA 和悬浮物（SS）去除的影响。由于 SS 对 PFOA 具有高吸附亲和力，因此大部分 PFOA 被吸附在颗粒上，并通过 SS 在混凝过程中的去除而被去除。水相中 PFOA 浓度随初始浊度和 PACl 剂量的增加而降低，随溶液 pH 值和温度的升高而升高。还比较了具有不同 C-F 链长和官能团的其他全氟化合物（PFCs）与 PFOA 的关系。证明疏水性相互作用在 SS 上对 PFOA 的吸附中起重要作用。在混凝过程之前添加粉末活性炭（PAC）可显著提高水中 PFOA 的去除效率，当初始 PFOA 浓度在 0.5-3 mg/L 范围内时，添加 1-16 mg/L PAC 并随后混凝后，水中的残留 PFOA 浓度小于 1μg/L。
