College of Architecture & Civil Engineering, Faculty of Urban Construction, Beijing University of Technology, Beijing 100124, China.
Junji Environment Technology Co., LTD, Wuhan 430070, China.
J Hazard Mater. 2023 May 5;449:131065. doi: 10.1016/j.jhazmat.2023.131065. Epub 2023 Feb 21.
The physicochemical properties of powdered activated carbon (PAC) are important factors affecting its adsorption performance, which is also related to the characteristics of target organic pollutants. In this study, the key indicators affecting the adsorption performance of PAC were identified, and the physicochemical properties of PACs were modified by hydrogen peroxide and/or ultrasound in a targeted manner to improve the adsorption performance. The results indicated the adsorption properties of printing and dyeing secondary effluent organic matter (EfOM) in terms of COD and UV absorbance at 254 nm (UV) positively correlated with mesoporous volume, average pore size and acid group content of PAC. After modification, the mesoporous volume and average pore size of PAC increased, and the number of acidic groups increased, thus enhancing the adsorption efficiency. EfOM removal characteristics showed that PAC preferentially adsorbed unsaturated bonds or aromatic compounds, tryptophan-like proteins, soluble microbial metabolites and low molecular weight fractions below 1 kDa. In addition, the relative contents of specific surface area, pore volume and oxygen-containing functional groups (O-CO, C-OH, CO/O-C-O) of PAC decreased after adsorption, indicating that EfOM adsorption was a physical and chemical process, including pore filling, hydrophobic interaction and chemical bond force interaction. In general, PACs with larger mesoporous volume, average pore size and abundant acid groups possessed good adsorption performance towards EfOM.
粉末活性炭（PAC）的物理化学性质是影响其吸附性能的重要因素，这也与目标有机污染物的特性有关。本研究确定了影响 PAC 吸附性能的关键指标，并通过过氧化氢和/或超声波有针对性地修饰 PAC 的物理化学性质，以提高其吸附性能。结果表明，PAC 对印染二级出水有机物（EfOM）的吸附性能（以 COD 和 254nm 处的紫外吸光度（UV）表示）与 PAC 的中孔体积、平均孔径和酸性基团含量呈正相关。改性后，PAC 的中孔体积和平均孔径增大，酸性基团数量增加，从而提高了吸附效率。EfOM 的去除特性表明，PAC 优先吸附不饱和键或芳香族化合物、色氨酸样蛋白、可溶性微生物代谢物和 1kDa 以下的低分子量物质。此外，PAC 对 EfOM 的吸附后比表面积、孔体积和含氧官能团（O-CO、C-OH、CO/O-C-O）的相对含量降低，表明 EfOM 的吸附是一个物理化学过程，包括孔填充、疏水相互作用和化学键力相互作用。一般来说，具有较大中孔体积、平均孔径和丰富酸性基团的 PAC 对 EfOM 具有良好的吸附性能。
