胞外聚合物对活性污泥吸附去除全氟辛烷磺酸(PFOS)的影响  

Effect of Extracellular Polymeric Substance (EPS) on the Adsorption of Perfluorooctane Sulfonate (PFOS) onto Activated Sludge

作　　者：刘鑫彤 尹华[1] 彭辉[2] 李浩榕[1] 杨萍萍[1] 曹雅娟[1] 

机构地区：[1]华南理工大学环境与能源学院工业聚集区污染控制与生态修复教育部重点实验室广东省环境风险防控与应急处置工程技术研究中心,广州510006 [2]暨南大学化学系,广州510632

出　　处：《环境科学》2017年第8期3435-3441,共7页Environmental Science

基　　金：广东省科技厅公益研究与能力建设专项重点项目(2015B020215006);广州市科信局产学研协同创新重大专项(2014Y2-00523)

摘　　要：采用活性污泥和去除胞外聚合物(EPS)污泥作为吸附剂,探讨污泥吸附PFOS的机制和EPS在吸附过程中的作用.结果表明,活性污泥和去除EPS污泥吸附PFOS均符合准二级动力学方程,平衡吸附量(q_e)分别为0.46 mg·g^(-1)和0.38 mg·g^(-1),化学吸附占主要作用.吸附等温线可以用Freundlich、Langmuir及Temkin方程拟合.Ca^(2+)和Cu^(2+)通过离子架桥作用促进PFOS在污泥上的吸附.活性污泥吸附去除PFOS的效果明显优于去除EPS后的污泥.傅里叶红外光谱(FTIR)和X射线光电发射光谱(XPS)分析吸附前后的污泥官能团变化,发现去除了EPS的污泥中羟基、羧基和氨基活性基团减少,而这些基团是PFOS吸附过程中参与反应的主要成分.由此可见污泥EPS中蛋白质含有的羧基和氨基活性基团为PFOS提供了吸附反应位点,EPS在吸附过程中起到至关重要的作用.The adsorption of PFOS by activated sludge and EPS-removed sludge was conducted to investigate the adsorption mechanism of activated sludge and the effect of EPS on this adsorption process. The experimental results indicated that the adsorption process of PFOS onto activated sludge and EPS-removed sludge fitted the pseudo-second-order model,with equilibrium absorption capacities（ q_e）of 0. 46 mg·g^（-1）and 0. 38 mg·g^（-1）,respectively. The sorption isotherm accorded well with the Freundlich,Langmuir,and Temkin models. Chemisorption played an important role in the adsorption of PFOS on the activated sludge. Ca^（2＋）and Cu^（2＋）contributed to PFOS adsorption on the activated sludge through an ion-bridging effect. Adsorption efficiency was better on the normal activated sludge compared to the EPS-removed sludge. FTIR and XPS were used to analyze the variations of functional groups before and after sorption.The results showed that the amount of functional groups such as hydroxyl,carboxyl,and amidogen on EPS-removed sludge was lower;however,these functional groups were found to have participated in the PFOS adsorption process. It is concluded that carboxyl and amidogen contained in protein of EPS provided reaction sites for PFOS adsorption,thus EPS components played a vital role in PFOS adsorption on the activated sludge.

关 键 词：活性污泥 全氟辛烷磺酸 胞外聚合物 活性基团 吸附机制 

分 类 号：X703.1[环境科学与工程—环境工程]