School of Environment and Energy, South China University of Technology, Guangzhou 510006, China.
Guangdong Provincial Key Laboratory of Environmental Health and Land Resource, Zhaoqing University, Zhaoqing 526061, China.
J Environ Sci (China). 2023 Jul;129:45-57. doi: 10.1016/j.jes.2022.08.026. Epub 2022 Aug 30.
Surfactant enhanced elution is an effective method for removing hydrophobic organic pollutants from soils. The key to the development of leaching technology is selective removal of targeted pollutants in soil washing effluent and recycling of surfactant solutions. In this study, a molecular imprinting technique was applied to selectively sorb polybrominated diphenyl ethers (PBDEs) in soil washing effluent. The novel molecular imprinted polymers (MIPs) using different template molecules were synthesized by precipitation polymerization. Adsorption behaviors and mechanisms of MIPs were studied through experiments and theoretical calculations. The results show that 4-bromo-4'-hydroxybiphenyl and toluene can be effective imprinting molecule for MIPs synthesis. The maximal adsorption capacity of selected dummy molecular imprinted polymer (D-MIP) was 1032.36 µmol/g, and that of part molecular imprinted polymer (P-MIP) was 981.13 µmol/g. Their imprinting factors in 5 PBDEs adsorption ranged from 2.13 to 5.88, the recovery percentage of Triton X-100 can reach 99.09%, confirming the feasibility of reusing surfactant. Various PBDEs could be removed by MIPs, and Quantitative Structure Property Relationship analysis revealed that PBDEs' molecular volume, planarity, polarity, and hydrophobicity have major influences on their adsorption performance. DFT calculation revealed that Van der Waals force and hydrogen bonding played important roles during selective adsorption. These results can provide effective theoretical guidance for surfactant enhanced soil elution in practical engineering applications.
表面活性剂强化洗脱是一种从土壤中去除疏水性有机污染物的有效方法。洗脱技术的关键在于选择性地去除土壤洗脱液中的目标污染物并回收表面活性剂溶液。本研究采用分子印迹技术选择性地吸附土壤洗脱液中的多溴二苯醚（PBDEs）。采用沉淀聚合法合成了不同模板分子的新型分子印迹聚合物（MIPs）。通过实验和理论计算研究了 MIPs 的吸附行为和机理。结果表明，4-溴-4'-羟基联苯和甲苯可以作为 MIPs 合成的有效印迹分子。选择的虚拟分子印迹聚合物（D-MIP）的最大吸附容量为 1032.36 µmol/g，部分分子印迹聚合物（P-MIP）的最大吸附容量为 981.13 µmol/g。在 5 种 PBDEs 的吸附中，其印迹因子范围为 2.13-5.88，Triton X-100 的回收率可达 99.09%，证实了表面活性剂的重复使用是可行的。MIPs 可以去除各种 PBDEs，定量构效关系分析表明，PBDEs 的分子体积、平面性、极性和疏水性对其吸附性能有较大影响。DFT 计算表明，范德华力和氢键在选择性吸附过程中起重要作用。这些结果可为实际工程应用中的表面活性剂强化土壤洗脱提供有效的理论指导。
