Liu Xin-Tong, Yin Hua, Peng Hui, Li Hao-Rong, Yang Ping-Ping, Cao Ya-Juan
Key Laboratory of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangdong Provincial Engineering and Technology Research Center for Environmental Risk Prevention and Emergency Disposal, College of Environment and Energy, South China University of Technology, Guangzhou 510006, China.
Department of Chemistry, Jinan University, Guangzhou 510632, China.
Huan Jing Ke Xue. 2017 Aug 8;38(8):3435-3441. doi: 10.13227/j.hjkx.201701202.
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 () of 0.46 mg·g and 0.38 mg·g, 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 and Cu 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.
通过活性污泥和去除胞外聚合物（EPS）的污泥对全氟辛烷磺酸（PFOS）的吸附，研究活性污泥的吸附机制以及EPS对该吸附过程的影响。实验结果表明，PFOS在活性污泥和去除EPS污泥上的吸附过程符合准二级模型，平衡吸附容量分别为0.46 mg·g和0.38 mg·g。吸附等温线与Freundlich、Langmuir和Temkin模型拟合良好。化学吸附在PFOS在活性污泥上的吸附中起重要作用。Ca和Cu通过离子桥接作用促进了PFOS在活性污泥上的吸附。与去除EPS的污泥相比，普通活性污泥的吸附效率更高。利用傅里叶变换红外光谱（FTIR）和X射线光电子能谱（XPS）分析吸附前后官能团的变化。结果表明，去除EPS污泥上的羟基、羧基和氨基等官能团数量较少；然而，发现这些官能团参与了PFOS的吸附过程。得出结论，EPS蛋白质中含有的羧基和氨基为PFOS吸附提供了反应位点，因此EPS成分在PFOS在活性污泥上的吸附中起重要作用。
