酸化土壤DOM的结构组成及其对Cu(Ⅱ)的络合能力  

Structural Composition and Cu(Ⅱ)-complexation Ability of DOM from Acidified Soils

作　　者：左强 马双龙 王竞侦 高博强 宋佳 唐晓丹 化党领[1] 黄岩 ZUO Qiang;MA Shuanglong;WANG Jingzhen;GAO Boqiang;SONG Jia;TANG Xiaodan;HUA Dangling;HUANG Yan(College of Resource and Environmental Science,Henan Agricultural University,Zhengzhou 450046,China)

机构地区：[1]河南农业大学资源与环境学院,河南郑州450046

出　　处：《环境科学与技术》2025年第4期168-178,共11页Environmental Science & Technology

基　　金：河南省科技攻关项目(242102320181,232102320077);国家自然科学基金项目(42377067,42407089);河南省优秀青年基金项目(242300421148);河南农业大学拔尖人才项目(30500945)。

摘　　要：在土壤酸化与重金属污染问题日渐加剧的背景下,该文为研究酸化土壤中溶解性有机质(DOM)的结构组成及其对重金属的络合作用,在淮河上游丘陵平原地区选取3处不同酸化程度的黄褐土开展试验,通过紫外分光光度计、傅里叶变换红外光谱仪、三维荧光光谱技术、平行因子分析法,并结合荧光淬灭滴定实验进行分析。试验结果表明:随着土壤酸化程度的增加,DOM的分子量和芳香性逐渐下降,有更多的内源性DOM浸出,而DOM的腐殖化程度和稳定性则变化不大。随着Cu(Ⅱ)浓度的增加,DOM的羧基官能团减少,可能与部分蛋白质变性有关。土壤酸化增加会导致DOM与Cu(Ⅱ)的络合顺序发生变化,其中羧基为Cu(Ⅱ)络合反应的主要官能团。DOM与Cu(Ⅱ)的相互作用机制可以为土壤酸化条件下重金属离子的环境行为提供重要的理论支持,并为改良酸化土壤和控制重金属污染提供新思路。Against the background of increasingly severe soil acidification and heavy metal pollution,three yellow-brown soils(Y1,Y2,and Y3)with different acidification degrees were collected from the hilly plain area upstream in Huaihe River to study the structural compositions of dissolved organic matter(DOM)in acidified soils and its complexation ability for heavy metals using UV spectrophotometry,Fourier transform infrared(FTIR)spectrometry,3D fluorescence spectroscopy technique,parallel factor analysis method,and fluorescence quenching titration experiment.The results showed that with the increase of soil acidification,the molecular weight and aromaticity of DOM gradually decrease,accompanied by the leaching of more endogenous DOM.However,the overall humification degree and stability of DOM remain largely unchanged.Along with the increase of Cu(Ⅱ)concentration,carboxyl functional group of DOM decreased which might be related to the denaturation of some proteins.Increased soil acidification leaded to the complexation order change between DOM and Cu(Ⅱ),in which the carboxyl group was the main functional group for the Cu(Ⅱ)complexation reaction.The reported interaction mechanism between DOM and Cu(Ⅱ)can provide important theoretical support for the environmental behavior of heavy metal ions under soil acidification conditions,and new ideas for ameliorating acidified soil and controlling heavy metal pollution.

关 键 词：酸化土壤 溶解性有机质 重金属 络合 光谱分析 

分 类 号：X53[环境科学与工程—环境工程]