重庆紫色母岩及土壤As、Hg环境地球化学基线研究  

Environmental Geochemical Baseline of As and Hg in Purple Soil and Its Parent Rock in Chongqing

作　　者：李艳[1] 张薇薇 程永毅[1] 李忠意[1] 谢德体[1] 

机构地区：[1]西南大学资源环境学院,重庆400716 [2]重庆市合川区农业技术推广站,重庆401519

出　　处：《土壤学报》2017年第4期917-926,共10页Acta Pedologica Sinica

基　　金：国家自然科学基金项目(41671291)资助~~

摘　　要：为了掌握紫色土类中As和Hg在不同发育阶段土壤中元素含量的理论值(基线值),在重庆市合川区系统采集侏罗系沙溪庙组(J2s)紫色母岩及其不同发育程度的各土种样品,利用土壤"钛值"法测定和验证土壤发育程度;通过对土壤全量As、Hg的测定,采用标准化方法,建立紫色土类中灰棕紫泥土属As、Hg的环境地球化学基线模型。结果表明:侏罗系沙溪庙组(J2s)紫色母岩发育的土壤As、Hg的环境地球化学基线均表现为随土壤发育加深而轻度累积,As基线值大小顺序为母岩<石骨子土<半沙半泥土<大眼泥<紫黄泥,而Hg的基线值大小顺序为母岩<石骨子土<半沙半泥土<紫黄泥<大眼泥;Hg在土壤发育过程中的富集程度约大于As;深度发育土中As和Hg的化学基线值分别为5.94 mg kg-1、29.0μg kg-1,可作为重庆地区中性紫色土亚类、灰棕紫泥土属土壤污染评价的参考。[Objective] This study is oriented to acquire theoretical values （or baseline value） of As and Hg in purple soils different in developmental stage, to understand migration and accumulation processes of the elements in the soils, and to provide an accurate and reliable basis for evaluation of heavy metal pollution of the soil. [Method] Samples of the purple parent rock of the Jurassic Shaximiao Formation （J2s） and various soils species derived from the same parent rock, but different in developmental degree were collected according to the traditional nomenclature in Hechuan District of Chongqing, for analysis to determine and verify development degrees of the soil with the ＂titanium value＂ method of soil; To measure total As and total Hg in the soils, to build up environmental geochemical baseline models for As and Hg in the soils of the gray brown purple soil genus in the purple soil group, and to define the chemical baseline values for each soil along the developmental line. [Result] Results show that in terms ＂titanium value＂ , the soils followed an order of parent rock 〉 stony sub-soil 〉 half sand half mud 〉 big-eye mud 〉 purple yellow mud, which reflects that the sequence of the soils in development degree coincides with the traditional order of the soils along the soil development line and that the soil sampling complied with the requirements of the study; The environmental geochemical baselines of As and Hg in the soils were found both on the trend of slight accumulation with deepening soil development, in terms of baseline value of As, the soils followed an order of parent rock 〈 stony sub-soil 〈 half sand half mud 〈 big-eye mud 〈 purple yellow mud, while in terms of baseline value of Hg, the soils followed another order： parent rock - stony sub- soil 〈 half sand half mud 〈 purple yellow mud 〈 big-eye mud. According to enrichment coefficient Q, Hg is always higher than As in enrichment degree in the soils along the development line. [Conclusion] Due to the unique pe

关 键 词：母岩 紫色土 AS HG 环境地球化学基线 

分 类 号：X142[环境科学与工程—环境科学]