光卤石修饰生物炭活化过硫酸盐修复有机污染土壤  

Activation of persulfate with carnallite-modified biochar for remediation of organic-contaminated soil

作　　者：李嘉鑫 申龙飞 任更波 马小东 I Jiaxin;SHEN Longfei;REN Gengbo;MA Xiaodong(School of Energy and Environmental Engineering,Hebei University of Technology,Tianjin 300401,China)

机构地区：[1]河北工业大学能源与环境工程学院,天津300401

出　　处：《环境工程学报》2024年第7期1987-1996,共10页Chinese Journal of Environmental Engineering

基　　金：国家重点研发计划资助项目(2020YFC1808603);国家自然科学基金资助项目(22106037,21876042);河北省重点研发计划资助项目(21374204D,22374206D)。

摘　　要：过硫酸盐(PS)氧化技术被广泛应用于有机污染物土壤的修复,其中高效、环境友好型非均相催化剂的研发一直是PS氧化技术研究的热点和难点。天然矿物光卤石(CA)本身无法有效活化PS,但将其负载在生物炭上制备的复合催化剂CA-CS能够大幅提高生物炭的催化性能。研究结果表明,CA-CS的最佳添加量为土壤质量的0.5%,最佳PS浓度以及反应时间分别为10 mmol·L^(-1)和12 h,该条件下对土壤中苯酚的降解率为94.1%。猝灭实验和电化学表征表明,苯酚、CA-CS、PS构成一个电子供体-电子介导体-电子受体的三元络合体系,在CA-CS催化作用下,PS可以更快地从苯酚提取电子,通过电子转移路径对苯酚进行降解。此外,氧化后土壤的粒径显著降低,且土壤的化学组成未发生明显变化。本研究旨在为实际工程应用中修复有机污染土壤提供一种高效、绿色的非均相催化剂。The development of efficient and environmentally friendly heterogeneous catalysts has been a challenging and hot topic in the research of persulfate(PS)oxidation technology,widely applied for the remediation of soil contaminated with organic pollutants.The natural mineral carnallite(CA)alone cannot effectively activate PS,but when loaded onto biochar to form the composite catalyst CA-CS,it significantly enhanced the catalytic performance of biochar.The research findings indicated that the optimal addition amount of CA-CS was equivalent to 0.5%of the soil mass,with the best PS concentration at 10 mmol·L^(-1) and reaction time for 12 h,resulting in a degradation rate of 94.1%for phenol in soil under these conditions.Quenching experiments and electrochemical characterization demonstrated that phenol,CA-CS,and PS formed a ternary complex system of electron donor-electron mediator-electron acceptor.Under the catalytic action of CA-CS,PS could more efficiently extract electrons from phenol and degrade it through an electron transfer pathway.Additionally,the particle size of the soil significantly decreased after oxidation,while the chemical composition of remained soil relatively unchanged.It aims to provide an efficient and environmentally friendly heterogeneous catalyst for the remediation of organic polluted soil in practical engineering applications.

关 键 词：有机污染土壤 土柱实验 过硫酸盐 生物炭 电子转移 

分 类 号：X53[环境科学与工程—环境工程]