摘要
为研究白银区周边农田土壤环境中重金属的污染及来源特征,以期为农田土壤重金属污染防治提供科学依据,于2021年7月在白银区周边农田采集67个表层土壤样品(0~20 cm),用微波消解-电感藕合等离子体质谱分析技术开展重金属(Cr、Ni、Co、Cu、Zn、Cd、As、Hg、Pb)污染特征及Pb的同位素指纹特征分析,并利用正定矩阵因子分析(PMF)和铅同位素指纹技术等方法手段解析重金属的污染来源。结果表明,研究区域农田土壤已受到不同程度的重金属污染,大部分重金属含量是相应土壤背景值的3.25~130.24倍;其中As、Cd、Cu、Pb和Zn含量均超过相应的农用地土壤污染风险筛选值,超标率为57.6%~100%。正定矩阵因子分析结果表明,该研究区农田土壤重金属污染共4个主要来源,其中,Cr、Ni、Co主要来自自然源,Hg主要来自煤燃烧释放;Zn、Cu和Pb主要来自铅锌矿的采选及冶炼等工业活动源,Cd和As主要来自于污水灌溉和农药化肥施用等农业活动源。Pb同位素源解析结果证实农田土壤Pb主要来源于矿产开采及冶炼活动等工业源。本研究表明,人为来源是当地农田土壤重金属的主要污染来源,不同重金属的污染防控需采取有针对性地污染源头治理与控制措施。
In order to study the pollution characteristics and identify the potential sources of heavy metals in farmland soil in the suburbs of Baiyi,Gansu province,to provid a scientific basis for the prevention and control of heavy metal pollution in farmland soil,67 surface soil samples(0~20 cm)were collected from farmland around Baiyin in July 2021.The pollution levels of heavy metals(Cr,Ni,Co,Cu,Zn,Cd,As,Hg,Pb)and Pb isotopic characteristics were analyzed by the method of microwave digestion-inductively coupled plasma mass spectrometry.Positive matrix factorization(PMF)analysis and Pb isotope fingerprint technique were applied to do the source apportionment of these heavy metals.The results showed that the farmland soil had been polluted by heavy metals in different degrees.The contents of As,Cd,Cu,Pb and Zn were all higher than the corresponding risk screening values of soil pollution in agricultural land,with a exceed ratio of 57.6%~100%.PMF results showed that there were four main sources of heavy metal pollution in this farmland soil.Among them,Cr,Ni and Co could be mainly attributed to natural sources,which accounted to 22.2%;Hg mainly came from coal combustion,which accounted to 10.4%.While,Zn,Cu and Pb mainly originated from industrial sources such as Pb/Zn mining and smelting(24.1%);Cd and As mainly derived from agricultural sources,including sewage irrigation,pesticide and fertilizer application(43.3%).Lead isotope ratios confirmed that the Pb might come from industrial sources such as mining and smelting pollution.This study indicated that anthropogenic sources were largely responsible for the accumulation of heavy metals in the farmland soil in the suburb of Baiyin,targeted treatment and control of pollution sources should be taken for prevention and control of different heavy metals.
作者
尚婷婷
张亚群
周静
曹素珍
SHANG Ting-ting;ZHANG Ya-qun;ZHOU-Jing;CAO Su-zhen(Environmental Science Research Institute in Gansu Province,Lanzhou 730020,China;University of Science and Technology Beijing,Beijing 100083,China)
出处
《环境生态学》
2023年第4期19-26,共8页
Environmental Ecology
基金
甘肃省科技计划项目(20YF8WA026)
甘肃省自然科学基金(22JR5RA742)资助。
关键词
农田土壤
重金属污染
源解析
PMF
铅同位素
Farmland soil
heavy metal pollution
sources apportionment
positive matrix factorization
lead isotope
