包气带土壤DOM三维荧光表征及对砷污染的指示意义  

Characterization of DOM from Soil in Unsaturated Zone and Its Implications on Arsenic Mobilization into Groundwater

作　　者：黄爽兵[1] 王焰新[1] 曹菱[1] 王程[1] 余梅[1] 皮坤福[1] 贾陈忠[1] 

机构地区：[1]中国地质大学环境学院及生物地质与环境地质国家重点实验室,湖北武汉430074

出　　处：《地球科学（中国地质大学学报）》2012年第3期605-611,共7页Earth Science-Journal of China University of Geosciences

基　　金：国家自然科学基金重点项目(No.40830748);中法合作交流项目(No.40711120189)

摘　　要：为了解包气带土壤DOM组成特征,探索其对砷向地下水中迁移的影响,对江汉平原高砷区土壤DOM进行了三维荧光光谱分析.结果表明DOM主要为类腐殖质成分,芳香性官能团的减少导致荧光强度随包气带深度增加而变小,局部深度荧光信号不规则变化指示非均质土壤剖面上DOM组分或主导官能团的变化.平行因子分析表明,DOM组分可更细致地分解为4种组分,与微生物源的还原、氧化醌类和陆生的腐殖质富里酸类等相似.砷很可能在DOM腐殖质成分络合作用下与之随水体一起向下迁移,砷的迁移也可能与微生物源的醌类作用过程有关.三维荧光光谱分析准确、快速地刻画了包气带土壤DOM的组分类别及空间变化特征,初步揭示了DOM影响砷迁移的可能作用方式,为进一步的地下水砷污染机制的研究提供了重要的参考信息.3D fluorescent spectra analysis was conducted to understand the characteristics of dissolved organic matter DOM. from soil of unsaturated zone and its potential influence on arsenic transport into groundwater. The results show that the humicqike component is the major constituent of DOM. The decrease in fluorescence intensity with depth is attributed to the reduction in aromatic functional groups. The irregular variation of the intensity in localized depth indicates the changes in DOM components or its major functional groups on soil section. Fluorescence information of DOM can be specifically decomposed by PARAFAC into four components, which are respectively similar to microbial reduced quinones, microbial oxidized quinones, terrestrial fulvic acid and so on. It is suggested that arsenic may be complexed by humic-DOMs and migrate with them into groundwater and the mobilization of arsenic also can be associated with the microbial quinones. Thus, 3D fluorescent spectra have been demonstrated to be a convenient and effective tool in DOM characterization and facilitate further study on effects on arsenic mobilization.

关 键 词：土壤 DOM 地下水 砷污染 污染控制 环境工程 

分 类 号：X143[环境科学与工程—环境科学] R124[医药卫生—环境卫生学]