Fan Wenli, Sun Guangxi, Wang Qi, Yang Fan, Gao Yingxin, Yang Min
State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; National Engineering Research Center of Industrial Wastewater Detoxication and Resource Recovery, Research Center for Eco-Environmental Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
Sci Total Environ. 2023 May 1;871:161968. doi: 10.1016/j.scitotenv.2023.161968. Epub 2023 Feb 2.
Activated carbon is widely used to remove effluent organic matter (EfOM) from bio-treated coking wastewater. However, the critical carbon properties affecting adsorption performance are still unclear. Nine commercial powdered activated carbons (PACs) with different pore structures, surface functional groups, and surface charges were used to adsorb EfOM from bio-treated coking wastewater, which was fractionated according to their molecular weight (MW) and hydrophobicity. Good correlations were observed between the adsorption of biopolymers (MW > 20,000 Da, 7 %) and macropore volume (>50 nm), as well as between the adsorption of humics (MW = 1000 ~ Da, 36 %) and mesopore volume (2-50 nm), suggesting that the adsorption sites of EfOM depended on their molecular size. Higher isoelectric points and fewer acidic groups promoted the adsorption of the most negatively charged hydrophobic acids (HPOA, 39.5 %). According to variation partitioning analysis (VPA), mesopore-macropore greatly contributed to the adsorption capacities of EfOM (71.3 %), whereas the sum of phenolic hydroxyl and carboxyl (26.3 %) and isoelectric point (12.2 %) affected the normalized adsorption capacities of EfOM. In conclusion, PAC with a higher mesopore volume, fewer acidic groups, and a higher isoelectric point was desirable for removing EfOM from bio-treated coking wastewater. This study provides guidance for the selection of PAC for the removal of EfOM from bio-treated coking wastewater.
活性炭被广泛用于去除生物处理后的焦化废水中的出水有机物（EfOM）。然而，影响吸附性能的关键碳特性仍不明确。使用九种具有不同孔结构、表面官能团和表面电荷的商业粉末活性炭（PAC）来吸附生物处理后的焦化废水中的EfOM，并根据其分子量（MW）和疏水性进行分级。观察到生物聚合物（MW > 20,000 Da，7%）的吸附与大孔体积（>50 nm）之间以及腐殖质（MW = 1000 ~ Da，36%）的吸附与中孔体积（2 - 50 nm）之间存在良好的相关性，这表明EfOM的吸附位点取决于其分子大小。较高的等电点和较少的酸性基团促进了带负电荷最多的疏水酸（HPOA，39.5%）的吸附。根据变异分配分析（VPA），中孔 - 大孔对EfOM的吸附容量贡献很大（71.3%），而酚羟基和羧基的总和（26.3%）以及等电点（12.2%）影响了EfOM的归一化吸附容量。总之，具有较高中孔体积、较少酸性基团和较高等电点的PAC对于从生物处理后的焦化废水中去除EfOM是理想的。本研究为从生物处理后的焦化废水中去除EfOM选择PAC提供了指导。
