摘要
为查明老工业城市土壤-作物系统的重金属环境地球化学特征,测试和分析石嘴山市水稻、小麦和玉米籽实及其根系土重金属含量和形态,利用统计学方法、风险评价编码法(RAC)、生物富集系数法(BCF)、土壤和农产品综合质量影响指数法(IICQ)及ArcGIS空间插值法开展土壤-作物系统重金属的迁移累积特征剖析及风险协同评价.结果表明,根系土中重金属ω(As)、ω(Cd)、ω(Cr)、ω(Cu)、ω(Hg)、ω(Ni)、ω(Pb)和ω(Zn)均值分别为12.56、0.19、63.48、23.52、0.038、28.86、21.68和69.47 mg·kg^(-1),与宁夏土壤背景值相比呈一定程度的累积,其中以Cd和Hg累积效应最为显著,但均低于农用地土壤污染风险筛选值;配套作物中上述8种重金属含量均值分别为0.0149、0.0112、0.075、6.7、0.0015、0.67、0.0427和20.48 mg·kg^(-1),与食品中污染物限量相比,作物中As、Pb和Cr点位超标率分别为4%、3%和1%,其余元素均未超标;相比水稻和小麦,根系土中重金属不易向玉米籽实中迁移,玉米的重金属综合影响程度较低;耕地土壤区域上为轻微亚污染状态,仅10%样点处于轻微(亚)污染-中度亚污染、可通过改种玉米降低作物重金属污染风险.
In order to explore the environmental geochemistry characteristics of heavy metals(HMs)in soil-crop systems in an old industrial city,the concentration and fraction of HMs in the paddy,wheat,and maize root soil and their seeds were detected and analyzed.Subsequently,statistical methods,risk assessment coding(RAC),the bio-enrichment coefficient factor(BCF),influence index of comprehensive quality(IICQ),and ArcGIS spatial interpolation were used to conduct the translocation,accumulation,and comprehensive risk assessment of HMs in soil-crop systems.The results showed that the average concentrations of As,Cd,Cr,Cu,Hg,Ni,Pb,and Zn in root soil were ranked respectively as follows:12.56,0.19,63.48,23.52,0.038,28.86,21.68,and 69.47 mg·kg^(-1).HMs in root soil were accumulated to some extent in comparison with the soil background value in Ningxia,especially Cd and Hg,but did not exceed the soil environmental pollution screening value(GB 14618-2018).The average concentrations of the eight aforementioned elements in supporting crop seeds were 0.0149,0.0112,0.075,6.7,0.0015,0.67,0.0427,and 20.48 mg·kg^(-1)in turn.The over-limit ratio of As,Pb,and Cr in crop seeds was 4%,3%,and 1%,respectively,relative to the national food safety standards(GB 2762-2017),whereas the other five elements were within the allowable range.In comparison to those in paddy and wheat,HMs hardly tended to translocate to maize seeds from root soil.According to the results of IICQ in soil-crop systems,the cultivated soil was in the state of slight sub-contamination regionally,and only 10%of sampling points showed slight(sub-)contamination-submoderate contamination,where we could replant maize to reduce HMs contamination risk.
作者
王莹
董爱俊
杨建锋
马彦斌
王泽晶
杨凡燕
WANG Ying;DONG Ai-jun;YANG Jian-feng;MA Yan-bin;WANG Ze-jing;YANG Fan-yan(School of Earth Science and Resources,China University of Geoscience,Beijing 100083,China;Ningxia Institute of Elementary Geological Survey,Yinchuan 750021,China;Geophysical and Geochemical Exploration Institute of the Ningxia Hui Autonomous Region,Yinchuan 750004,China)
出处
《环境科学》
EI
CAS
CSCD
北大核心
2023年第8期4429-4439,共11页
Environmental Science
基金
宁夏自然科学基金项目(2021AAC03444)
宁夏第二批青年人才托举工程项目。
关键词
重金属
土壤-作物
迁移累积
协同评价
石嘴山
heavy metals
soil-crop
translocation and accumulation
comprehensive assessment
Shizuishan
