Perfluorooctanoic acid (PFOA) is nonbiodegradable, and adsorption is the main pathway for its removal in wastewater treatment plants (WWTPs). This study compared the capability of three types of sludge on adsorbing PFOA and investigated the role of extracellular polymeric substances (EPS) in the adsorption process. Results show that enhanced biological phosphorus removal (EBPR) sludge had the highest adsorption capacity for PFOA. Studies on the interaction between EPS and PFOA reveal that proteins play a crucial role in binding PFOA to EPS/sludge. Specifically, the aromatic and amide groups on the structure of protein can attract the C–F chains and carboxylic head of PFOA via hydrophobic interaction and electrostatic attraction, respectively. EPS of EBPR sludge has the highest amount of protein and binding sites, thus exhibits the highest adsorption capability for PFOA. This study reveals the interaction mechanism between PFOA and sludge EPS and provides new insight into the function of EPS in perfluoroalkyl substances removal in WWTPs.

全氟辛酸（PFOA）是不可生物降解的，吸附是其在废水处理厂（WWTP）中去除的主要途径。这项研究比较了三种污泥对PFOA的吸附能力，并研究了细胞外聚合物（EPS）在吸附过程中的作用。结果表明，增强的生物除磷污泥对PFOA的吸附能力最高。对EPS和PFOA之间相互作用的研究表明，蛋白质在将PFOA与EPS /污泥结合方面起着至关重要的作用。特别是，蛋白质结构上的芳族和酰胺基团可以分别通过疏水作用和静电吸引作用吸引PFOA的CF链和羧基。EBPR污泥的EPS具有最高的蛋白质和结合位点，因此对PFOA的吸附能力最高。这项研究揭示了PFOA与污泥EPS之间的相互作用机理，并为EPS在污水处理厂全氟烷基物质去除中的功能提供了新的见解。