摘要
为探究矿区农田土壤重金属输入与输出通量特征,本试验以长江下游某典型遗留硫铁矿区小流域为研究区域,分析研究区土壤重金属(Cd、Pb、Cu、Zn、Cr)的空间分布特征,并设置监测田块,核算研究区土壤重金属输入与输出通量及构建含量预测模型。结果表明:硫铁矿区小流域土壤重金属污染元素主要是Cd、Cu、Zn,分别有5.88%、33.99%和13.07%的土壤样品超过农用地土壤污染风险筛选值(GB 15618—2018),水稻籽粒中Cd和Cr超过《食品安全国家标准食品中污染物限量》(GB 2762-2017)中限量值的点位比例分别为36.00%和13.33%;土壤Cd、Cu、Zn的空间分布呈现上游矿坑周边及下游水库入口处含量高的趋势,且三者间存在显著正相关关系(P<0.01),而Pb和Cr的空间分布与之不同,其中Cr与其他元素呈现负相关关系;根据监测田块核算,研究区Cd、Cu、Pb、Zn、Cr的年输入通量分别为15.62、86.63、292.92、325.89、90.30 g·hm^(-2)·a^(-1),年输出通量分别为2.85、0.32、37.20、196.15、5.94 g·hm^(-2)·a^(-1),土壤重金属呈现不断累积的特征;预测Cd和Cu在未来20 a间含量会明显增加,Pb、Zn、Cr反之。综上,加强上游矿区的水源治理,提倡下游农田科学灌溉,减少灌溉水中Cd等重金属输入是土壤重金属污染源头防控的关键。
A small watershed of an abandoned pyrite mining area in the lower reaches of the Yangtze River was selected as the study area to explore the characteristics of heavy metals input and output fluxes in farmland soil of mining areas.We analyzed the spatial distribution characteristics of heavy metals(Cd,Pb,Cu,Zn,Cr)in soils by setting up monitoring fields to calculate the input and output fluxes of heavy metals in the soil of the study area and construct a content of heavy metals prediction model.The results showed that:Cd,Cu,Zn were the main heavy metal pollutant elements in the soil of the small watershed in the pyrite mining area,with 5.88%,33.99%,and 13.07%of the soil samples exceeding the risk screening values for soil pollution in agricultural land(GB 15618—2018),respectively.The proportions of Cd and Cr in rice grains exceeding the"National Food Safety Standard for Pollutant Limits in Food"(GB 2762—2017)were 36.00%and 13.33%,respectively.The spatial distribution of Cd,Cu,Zn in soil showed a trend of high content around the upstream mining pit and at the entrance of the downstream reservoir,and there was a significant positive correlation between them(P<0.01),while the spatial distribution of Pb and Cr were different,and Cr showed a negative correlation trend with the other elements.According to monitoring field calculating,the total annual input fluxes of Cd,Cu,Pb,Zn,Cr in paddy soils were 15.62,86.63,292.92,325.89,90.30 g·hm^(-2)·a^(-1),respectively,and the total annual output fluxes were 2.85,0.32,37.20,196.15,5.94 g·hm^(-2)·a^(-1),respectively.Soil heavy metals exhibited a continuous accumulation characteristic.It was predicted that the content of Cd and Cu would significantly increase in the next 20 years while the content of Pb,Zn,Cr would decrease.In conclusion,strengthening water source management in upstream mining areas,advocating scientific irrigation in downstream farmland,and reducing the input of heavy metals such as Cd into irrigation water is crucial for the prevention and control of so
作者
赵归梅
吴秋梅
胡文友
黄标
祖艳群
李元
湛方栋
ZHAO Guimei;WU Qiumei;HU Wenyou;HUANG Biao;ZU Yanqun;LI Yuan;ZHAN Fangdong(College of Resources and Environment,Yunnan Agricultural University,Kunming 650201,China;State Key Laboratory of Soil&Sustainable Agriculture,Institute of Soil Science,Nanjing 210008,China;Sino-Danish College,University of Chinese Academy of Sciences,Beijing 101408,China)
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2024年第7期1492-1502,共11页
Journal of Agro-Environment Science
基金
江苏省重点研发计划项目(BE2021717)
江苏省农业科技自主创新资金项目[CX(21)2034]
中国科学院青年创新促进会会员项目(2019312)。
关键词
硫铁矿区
重金属
空间分布
输入-输出通量
预测模型
pyrite mining area
heavy metal
spatial distribution
input and output fluxes
predictive model
