生物质热成烟气溶解性有机质与Cu^(2+)和Cd^(2+)的络合特性及机制研究  

Binding characteristics and mechanism of biomass burning smoke-derived dissolved organic matter with Cu^(2+)and Cd^(2+)

作　　者：程玥 王志耿 代琴 钟寅华 张慧颖 陈卫锋[1,2] 倪进治 魏然[3,4] CHENG Yue;WANG Zhigeng;DAI Qin;ZHONG Yinhua;ZHANG Huiying;CHEN Weifeng;NIJinzhi;WEI Ran(Institute of Geography,Fujian Normal University,Fuzhou 350007;Fujian Provincial Key Laboratory for Plant Eco-physiology,Fujian Normal University,Fuzhou 350007;Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education,Fujian Normal University,Fuzhou 350007;School of Geographical Science,Fujian Normal University,Fuzhou 350007)

机构地区：[1]福建师范大学地理研究所,福州350007 [2]福建省植物生理生态重点实验室,福州350007 [3]福建师范大学湿润亚热带生态地理过程教育部重点实验室,福州350007 [4]福建师范大学地理科学学院,福州350007

出　　处：《环境科学学报》2024年第11期230-243,共14页Acta Scientiae Circumstantiae

基　　金：国家自然科学基金(No.42077130);福建省自然科学基金(No.2020J01137,2022R1002003)。

摘　　要：由于全球野火的频发和秸秆的肆意焚烧,生物质燃烧产生的溶解性有机质(BBS-DOM)的环境效应备受关注.BBS-DOM最终沉降在水体和土壤环境中,并可改变地表环境中污染物(如重金属)的环境行为和归趋.然而,BBS-DOM与重金属之间的络合特性尚不清楚.本研究通过燃烧苜蓿、松木和玉米秸秆制备不同的BBS-DOM,并选择Cu^(2+)和Cd^(2+)为模型污染物,络合滴定实验、二维同步荧光光谱(2D-SFS-COS)和二维红外光谱(2D-FTIR-COS)研究了BBS-DOM与重金属之间的络合特性.结果表明,BBS-DOM与Cu^(2+)络合优先顺序为类蛋白物质>类腐殖酸物质>多酚类物质,与Cd^(2+)络合优先顺序为多酚类物质和类腐殖酸物质>类蛋白物质.此外,BBS-DOM中官能团与Cu^(2+)和Cd^(2+)的络合顺序因原料类型不同而有所差异.苜蓿燃烧产生的BBS-DOM中官能团与Cu^(2+)和Cd^(2+)络合顺序为芳环C=C>C-O-C/C-O>-C=O,松木和玉米秸秆燃烧产生的BBS-DOM中的-C=O优先与Cu^(2+)络合,而松木燃烧产生的BBS-DOM中的芳环C=C优先与Cd^(2+)络合,玉米秸秆燃烧产生的BBS-DOM与Cd^(2+)的官能团络合顺序为C-O-C/C-O>芳环C=C.此外,本研究还发现Cu^(2+)的加入增加了BBS-DOM的分子大小,可能是因为Cu^(2+)起到桥接作用,将多个BBS-DOM分子聚合成更大的分子.本研究为在分子水平上深入理解BBS-DOM在水环境中与Cu^(2+)和Cd^(2+)络合的机制提供了重要的理论基础,为合理评估BBS-DOM在水环境中的环境效应提供了科学依据.Owing to the frequent occurrence of wildfires and burning of straw around the world,the environmental effects of biomass burning smokederived dissolved organic matter(BBS-DOM)have attracted increasing attention.BBS-DOM eventually deposits on the water and soil environments,thus altering the environmental behaviors and fates of pollutants(e.g.,heavy metals)in the surface environments.However,the binding characteristics between heavy metals and BBS-DOM remain unknown.In this study,different BBS-DOMs were prepared by burning alfalfa,pinewood and corn straw,Cu^(2+)and Cd^(2+)were selected as the model pollutants,and the binding characteristics between BBS-DOM and heavy metals(Cu^(2+)and Cd^(2+))were investigated by titration experiments,synchronous fluorescence spectra combined with two-dimensional correlation spectroscopy(2D-SFS-COS)and FTIR combined with two-dimensional correlation spectroscopy(2D-FTIR-COS).The results showed that the binding priority with Cu(II)of various BBS-DOMs followed a consistent order of protein-like matters>humic-like matters>polyphenols-like matters,and the binding priority with Cd^(2+)followed the order of polyphenols and humic-like matters>protein-like matters.In addition,the binding order of functional groups with Cu^(2+)and Cd^(2+)in BBSDOM depended on the biomass types.The binding order of functional groups with Cu^(2+)and Cd^(2+)for the BBS-DOM derived from alfalfa followed aromatic ring C=C>C-O-C/C-O>-C=O.The-C=O group in the BBS-DOMs derived from pinewood and corn straw preferentially bound with Cu^(2+),while the aromatic ring C=C in the BBS-DOM derived from pinewood preferentially bound to Cd^(2+).The binding order of functional group with Cd^(2+)for BBS-DOM derived from corn straw followed C-O-C/C-O>aromatic ring C=C.Furthermore,the addition of Cu^(2+)could increase the molecular size of BBS-DOM,which was possibly due to that Cu^(2+)could be a bridge to bind multiple BBS-DOM molecules and make them aggregate to a lager molecule.This study provides an important theoretical basis

关 键 词：生物质热成烟气溶解性有机质 Cu^(2+) Cd^(2+) 有机组分 官能团 络合特性 

分 类 号：X131[环境科学与工程—环境科学]