煤化工渣高效吸附去除水中全氟辛酸

为高效快速去除水中全氟辛酸，选择工业废物煤化工渣对全氟辛酸进行吸附去除探究。采用不同的处理方法制备了4种煤化工渣（粒径从大到小为CGA1、CGA2、CGA3和CGA4），研究其在水溶液中的全氟辛酸吸附性能。利用扫描电子显微镜（SEM）、拉曼光谱、傅里叶变换红外光谱（FTIR）和X射线光电子能谱（XPS）对4种煤化工渣的结构特征进行表征分析，并考察了全氟辛酸初始质量浓度和初始pH对吸附进程的影响。实验结果表明：煤化工渣对全氟辛酸有高效的吸附能力，伪二级动力学模型和Langmuir等温模型可以较好地描述4种煤化工渣对全氟辛酸的吸附行为及过程，其中CGA4去除全氟辛酸的最大吸附量为25.51 mg/g；随着全氟辛酸溶液初始质量浓度升高，煤化工渣对全氟辛酸的吸附容量逐渐增加；初始pH对CGA3和CGA4的影响微弱，CGA1和CGA2在酸性条件下显示出更优越的吸附性能。由此得出，4种煤化工材料中粒径最小的CGA4具有最优的全氟辛酸去除能力且基本不受pH限制。FTIR分析表明，吸附过程中氢键的形成占主导地位，XPS和Zeta电位检测结果表明，物理吸附和静电吸附在去除过程中也发挥了重要作用。

Removal of Perfluorooctanoic Acid (PFOA) in Aqueous Solution Using Highly Adsorptive Coal Chemical Slag

Industrial waste coal chemical residues were selected as absorbent to remove perfluorooctanoic acid (PFOA) in water. Four kinds of coal chemical slag (particle size range from large to small was CGA1, CGA2, CGA3, and CGA4) prepared by different treatment methods were used to evaluate their sorption performance for PFOA. Scanning electron microscope (SEM), Raman, Fourier transform infrared (FTIR), and X-ray photoelectron spectroscopy (XPS) were used to characterize the structures of the four kinds of coal chemical slag, and the effects of initial concentration and pH of the PFOA solution on the adsorption process were investigated. The results showed that the absorbents had high efficiency for PFOA removal. The adsorption was well described by the pseudo-second-order kinetic model and the Langmuir isothermal model. With the increase of the initial concentration of PFOA solution, the adsorption capacity of the coal chemical slag for PFOA increased gradually. The initial pH value had almost no impact on CGA3 and CGA4; While for CGA1 and CGA2, it showed better adsorption performance under acidic conditions than alkaline conditions. It is concluded that CGA4 (the smallest particle size) has the best PFOA removal ability and is almost unrestricted by pH. The maximum adsorption capacity of CGA4 is 25.51 mg/g. The FTIR analysis suggested that the formation of hydrogen bonds dominates the adsorption process. The results of XPS and zeta potential showed that physical and electrostatic adsorption also plays important roles in the removal progress. Therefore, coal chemical slag can be used as a promising adsorbent to remove the difficult-to-treat pollutants and promote the recycling of waste and sustainable development.