亚铁活化过硫酸盐体系对水体溶解性有机质分子转化的影响  

Effect of Persulfate/Ferrous Advanced Oxidation System on Molecular Transformation of Dissolved Organic Matter in Water

作　　者：曹惠真 孙宗全 沈佳伦 王佳琪 李晓东[1] 马福俊[1] 谷庆宝[1] CAO Huizhen;SUN Zongquan;SHEN Jialun;WANG Jiaqi;LI Xiaodong;MA Fujun;GU Qingbao(Institute of Soil and Groundwater Environment,Chinese Research Academy of Environmental Sciences,Beijing 100012,China;College of Environmental Science and Engineering,Beijing Forestry University,Beijing 100083,China)

机构地区：[1]中国环境科学研究院土壤和地下水环境研究所,北京100012 [2]北京林业大学环境科学与工程学院,北京100083

出　　处：《环境科学研究》2024年第8期1749-1759,共11页Research of Environmental Sciences

基　　金：国家自然科学基金项目(No.42307339)。

摘　　要：亚铁活化过硫酸盐(PS/Fe^(2+))高级氧化是修复有机污染水体的常用技术,在修复过程中会诱导水体中溶解性有机质(DOM)分子结构转变。为研究PS/Fe^(2+)体系中DOM的分子转化特性,选取腐殖酸(HA)、富里酸(FA)和天然有机质(NOM)3种不同种类的DOM为研究对象,利用光谱和高分辨率质谱对比分析了PS/Fe^(2+)反应前后DOM的理化特性和分子结构特征。结果表明:①与热或碱活化PS体系相比,PS/Fe^(2+)反应后DOM芳香度、分子数和分子量显著下降。②反应后,DOM中残留了含C、H和O的木质素和单宁类物质,去除了O/C<0.6的低氧化程度分子,生成了富含氮和硫的高氧化程度分子。③PS/Fe^(2+)体系去除了DOM中的不饱和态分子(49.3%~94.0%),生成饱和态物质的数量、类型因DOM种类表现出明显差异。研究显示,PS/Fe^(2+)体系在自由基氧化与络合作用的共同介导下显著增加了DOM的分子转化程度,进而可能影响共存污染物的环境行为。Persulfate/ferrous(PS/Fe^(2+))-based advanced oxidation is commonly used for remediation of organic pollutants in groundwater,which can cause changes in the molecular structure of dissolved organic matter(DOM)during the remediation process.In order to investigate the transformation characteristics of DOM molecules after PS/Fe^(2+)reaction,three distinct components of DOM,namely humic acid(HA),fulvic acid(FA),and bulk natural organic matter(NOM),were selectively chosen.The physicochemical properties and molecular structure of DOM before and after PS/Fe^(2+)reaction was compared and analyzed using spectroscopy and high-resolution mass spectrum.The results showed that:(1)The aromaticity,molecular number and molecular weight of DOM were significantly decreased after PS/Fe^(2+)reaction compared with the PS/heat and PS/base system.(2)Lignin and tannin containing CHO of DOM were remained,low oxidation state molecules with O/C<0.6 were removed,and the high oxidation states molecules rich in nitrogen(N)and sulfur(S)were generated after PS/Fe^(2+)reaction.(3)The unsaturated molecules in DOM were primarily removed(49.3%-94.0%)by PS/Fe^(2+)system,while the amount and type of saturated substances were different from each DOM type.The study indicates that the PS/Fe^(2+)system significantly enhances DOM molecular transformation,mediated jointly by radical oxidation and complexation with Fe3+.Consequently,this process may further affect the environmental behavior of coexisting pollutants.

关 键 词：溶解性有机质(DOM) 亚铁 过硫酸盐(PS) 高分辨质谱 分子转化 

分 类 号：X523[环境科学与工程—环境工程]