黔中某茶园重金属污染特征及防治对策

Characteristics and Prevention Measures of Heavy Metal Pollution in a Tea Garden in Central Guizhou

为了解黔中山区土壤和茶叶重金属含量、风险及来源,以黔中某农旅一体化茶园为研究对象,对应采集土壤与茶叶样品各30个,测定重金属镉(Cd)、汞(Hg)、砷(As)、铬(Cr)、铅(Pb)、铜(Cu)、锌(Zn)含量,运用内梅罗综合污染指数法、潜在生态危害指数法、目标危害系数与综合影响指数对茶园土壤和茶叶重金属污染特征及风险进行评价,结合相关性分析与组成份分析探究茶园土壤和茶叶重金属的主要来源,提出相应的防治措施。结果表明:研究区茶园土壤Cd、As、Hg、Cr、Pb、Cu、Zn的平均含量分别为0.14、16.92、0.24、62.93、25.48、54.59、56.84 mg/kg;茶叶Cd、As、Hg、Cr、Pb、Cu、Zn的平均含量分别为0.048、0.049、0.022、0.630、0.305、26.949、53.417 mg/kg。土壤重金属综合污染指数显示有50.00%的点位存在Cu污染,3.30%的点位存在Cd与As污染,茶叶重金属综合污染指数为0.33,表明茶叶未受到重金属污染,土壤重金属综合生态危害指数为51.84,生态危害指数为轻微,土壤和茶叶综合质量影响指数显示茶园土壤有50.00%的点位受到重金属污染,Cu是造成土壤污染的主要元素,饮茶重金属摄入风险<1,表明土壤与饮茶摄入的重金属不会对人体造成健康风险。要防治茶园土壤和茶叶重金属污染,必须减少车辆进入茶园,施用无重金属有机肥,控制重金属的带入,减少茶园重金属污染。

In order to understand the content,risk and source of soil-tea heavy metal in the mountain area of central Guizhou,where an integrated tea garden was taken as the research object,and 30 soil and 30 tea samples were collected respectively to determine the contents of heavy metals Cd,As,Hg,Cr,Pb,Cu and Zn.The pollution characteristics and risks of soil-tea heavy metal were evaluated using Nemero comprehensive pollution index method,potential ecological hazard index method,target hazard coefficient(THQ)and comprehensive impact index,combined with correlation analysis and components analysis.The results showed that the average contents of Cd,As,Hg,Cr,Pb,Cu and Zn in the tea garden soil of the study area were 0.14,16.92,0.24,62.93,25.48,54.59 and 56.84 mg/kg,respectively.The average content of tea was 0.048,0.049,0.022,0.630,0.305,26.949,53.417 mg/kg.The comprehensive pollution index of heavy metal in soil showed that there were 50%of Cu pollution,3.3%of Cd and As pollution,and the heavy metal pollution index of tea was 0.331,indicating that the tea was contaminated by heavy metals,and the comprehensive ecological hazard index of heavy metals in soil was 51.84,and the ecological hazard index was slight.The soil-tea comprehensive quality impact index(IICQS)indicates that 50%of the tea garden soil was contaminated by heavy metals,and Cu was the main element causing soil pollution,and the risk of heavy tea intake in drinking tea was THQ<1,indicating that the intake of heavy metals in soil and tea drinking does not pose a health risk to human beings.In order to prevent and control heavy metal pollution in tea garden soil and tea,it is necessary to reduce vehicle entry into tea garden,apply organic fertilizer without heavy metals,control the introduction of heavy metals,and reduce heavy metal pollution in tea garden.