水分非饱和条件下土壤矿物界面有毒有机物转化机制研究进展  

Research Progress on the Transformation Mechanism of Toxic Organic Pollutants on Soil Mineral Interface under Water-unsaturated Conditions

作　　者：程鹏飞 赵旭强 秦超 高彦征[1] CHENG Pengfei;ZHAO Xuqiang;QIN Chao;GAO Yanzheng(Institute of Organic Contaminant Control and Soil Remediation,Nanjing Agricultural University,Nanjing 210095,China)

机构地区：[1]南京农业大学土壤有机污染控制与修复研究所,南京210095

出　　处：《土壤学报》2024年第3期594-606,共13页Acta Pedologica Sinica

基　　金：国家杰出青年科学基金项目(41925029);江苏省碳达峰碳中和科技创新专项资金项目(20220013)资助。

摘　　要：土壤矿物作为土壤重要活性组分,可驱动土壤有毒有机物化学转化,降低污染风险。以往土壤矿物与有毒有机物界面行为研究主要集中于水环境或矿物悬浊液体系,然而实际环境中土壤及其矿物常处于干燥、湿润等水分非饱和状态。近年来,水分非饱和条件下土壤矿物界面有毒有机物转化及机制已成为研究热点,相关研究获得一系列新发现。低含水量铁锰矿物、黏土矿物和金属离子饱和黏土矿物能驱动多环芳烃、抗生素等疏水性有毒有机物化学转化。水分非饱和环境会减弱矿物界面水分子与有毒有机物竞争活性位点,并使矿物发生脱水、向高活性结构转变。此外,土壤矿物水分状态也会影响有毒有机物转化产物,水分非饱和环境更有利于持久性自由基和卤代二英等中间产物的形成和稳定。以往研究认为,电子转移反应是土壤矿物界面有毒有机物转化机制,随着检测技术与理论计算的发展,自由基催化和水解作用机制逐渐被发现,相关机制研究精准至矿物晶型和晶面层面。虽然水分非饱和条件下土壤矿物界面有毒有机物转化及机制已逐渐清晰,但其研究广度和深度有待进一步拓宽和加深。建议未来在实际水分非饱和土壤和矿物中开展有毒有机物转化研究,深入探究还原转化过程,研发原位反应装置及检测方法,尝试从微纳米尺度和分子水平解析有毒有机物在矿物界面转化机制。Minerals are critical active components of soils,which can drive the chemical transformation of toxic organic pollutants in the soil environment and reduce the risk of environmental contamination.Previous studies of the interface behavior of toxic organic pollutants on soil mineral surfaces mainly focused on the water environment or mineral suspension systems.Natural soils,especially surface soils,are usually under water-unsaturated conditions.In recent years,the transformation mechanism of toxic organic pollutants on water-unsaturated soil mineral surfaces has attracted considerable attention,and a series of fascinating discoveries have been made.The water-unsaturated iron and manganese minerals,clay minerals and metal ion-saturated clay minerals drive the transformation of the hydrophobic toxic organic pollutants such as polycyclic aromatic hydrocarbons and antibiotics.Water molecules at the interface of water-unsaturated minerals have weak competition with toxic organic pollutants for active sites,and the dehydration process of minerals also makes them change to highly active structures.However,an appropriate increase in the moisture of dry soil minerals can enhance the transformation of toxic organic pollutants.A small amount of water molecules can improve mass transfer and promote the transfer of toxic organic pollutants to the active sites of soil minerals.The different moisture state of soil minerals leads to the formation of various products.The water-unsaturated condition is more conducive to the formation and stability of persistent free radicals and halogenated dioxins.Also,the transformation of toxic organic pollutants is influenced by the catalytic activity of soil minerals and the physical and chemical properties of toxic organic pollutants.In previous studies,electron transfer reaction was considered as the transformation mechanism of toxic organic pollutants on soil minerals.However,free radical catalysis and hydrolysis mechanisms have been gradually discovered.Transition metal elements in iron ma

关 键 词：水分非饱和条件 有毒有机物 黏土矿物 铁锰矿物 转化 

分 类 号：X13[环境科学与工程—环境科学]