江苏典型农田土壤重金属形态分布初步研究  

Distribution of Soil Heavy Metals and Their Speciation in Typical Farmlands in JiangsuProvince

作　　者：汪媛媛[1] 廖启林[1] 李文博[1] 徐宏婷 崔晓丹[1] 刘玮晶 李文婷 周强 WANG Yuanyuan;LIAO Qilin;LI Wenbo;XU Hongting;CUI Xiaodan;LIU Weijing;LI Wenting;ZHOU Qiang(Technology Innovation Center for Ecological Monitoring&Restoration Project on Land(Arable),Ministry of Natural Resources,Geological Survey of Jiangsu Province,Nanjing 210018,China)

机构地区：[1]自然资源部国土(耕地)生态监测与修复工程技术创新中心,江苏省地质调查研究院,南京210018

出　　处：《土壤》2024年第6期1326-1338,共13页Soils

基　　金：江苏省自然资源发展专项资金(海洋科技创新)项目(JSZRHYKJ202117);江苏省基础研究计划暨自然科学基金项目(面上)(BK20171496);江苏省国土(耕地)生态地质环境监测项目(苏财建[2018]96号)资助。

摘　　要：采用改进的BCR形态分析4态法和相关土壤理化指标检测手段,测定江苏典型农田区459个土壤样品的Cd、Hg、Pb、As、Cr、Ni、Cu、Zn的可交换态、可还原态、可氧化态、残渣态含量及其全量等指标,以及常量元素含量和pH、总有机碳(TOC)和阳离子交换量(CEC),通过地球化学参数统计、相关分析和数据对比,探讨江苏农田土壤重金属形态分布特征及其相关规律,结果显示:①Cd以可交换态和可还原态为主,占比大于75%;Hg和Cr以残渣态为主,占比大于90%;Pb、As、Ni、Cu、Zn以可还原态和残渣态为主,占比大于87%;各重金属可氧化态占比均小于8.5%;②重金属形态组分同其全量之间多具有显著正相关性,相关系数r普遍大于0.5,可交换态、可还原态、可氧化态Cd同其全量的相关系数均大于0.9,可交换态Cd同稻米Cd的正相关性明显优于Cd全量;③pH、TOC、CEC、Si、Al、Na、K等都是影响重金属形态分布的重要因素,不同重金属及其形态受控因素有差异,如可交换态、可还原态、可氧化态Cd与pH、K之间存在较显著负相关性,而可氧化态Cu、Zn与TOC之间存在显著正相关性;④局地存在相近或相同的Cd、Cu、Zn、Se物质来源或富集机制,致使可交换态、可还原态、可氧化态Cd、Cu、Zn与Se之间多具有显著正相关性;⑤Hg的形态分析合格率只有4.6%,不适合BCR形态分析法,而除Hg之外的其他重金属的形态和全量分析均不可或缺。To study and explore heavy metals distributive characteristics and their controlling factors,459 typical soil samples were systematically collected from the farmlands in Jiangsu Province,and heavy metal concentrations(Cd,Hg,Pb,As,Cr,Ni,Cu,Zn)and their speciation contents(exchangeable state,reducible state,oxidative state,residual state)were determined with the improved 4-state testing methods related to chemical state analysis from European Community BCR.Macro elements and other relevant soil physio-chemical parameters were also analyzed such as pH,TOC,and CEC,and geochemical parameter statistics and correlation analyses were used to analyze and compare these detected data.The results showed that:1)exchangeable and reducible state were the main speciation of Cd(accounting for more than 75%),residual state was the main speciation components of Hg and Cr(more than 90%),reducible and residual state were the main speciation of Pb,As,Ni,Cu and Zn(more than 87%in total),while oxidative state was less than 8.5%for every heavy metal;2)There were mostly significant positive correlation between heavy metals speciation contents and the total contents(correlated coefficients r general higher than 0.5,and r of Cd higher than 0.9),and the positive correlation between rice Cd with soil exchangeable state Cd was obviously higher than with soil total Cd;3)soil pH,TOC,CEC,Si,Al,Na,K were outright important factors to impact heavy metals speciation distribution,but controlling factors were obviously different for different heavy metals and their speciation,for example,there were significant negative correlations between exchangeable state,reducible state,oxidative state Cd with pH or K,and significant positive correlation between oxidative state Cu and Zn with TOC;4)Some similar or identical material sources or enriched mechanism may existed for Cd,Cu,Zn and Se in the farmland soils,resulting in significant positive correlation between Se with exchangeable state,reducible state,oxidative state of Cd,Cu and Zn;5)BCR speciation metho

关 键 词：重金属形态 分布 农田土壤 江苏 

分 类 号：P632[天文地球—地质矿产勘探] P596[天文地球—地质学]