贵州名优茶产区土壤-茶叶中重金属污染及迁移

选择贵州省云雾、都匀、湄潭3个典型名优茶产区,采集土壤和茶叶样品进行重金属检测分析。结果表明:贵州省茶园土壤主要重金属污染元素为Cd和Hg,3个茶产区中,湄潭茶产区土壤Cd的超标率最高,达到39.4%,都匀茶产区土壤Hg超标率最高,为24.2%。土壤Cd平均含量表现为都匀茶产区>湄潭茶产区>云雾茶产区,超标率表现为湄潭茶产区>都匀茶产区>云雾茶产区;土壤Hg含量和超标率均表现为都匀茶产区>湄潭茶产区>云雾茶产区。贵州省3个典型名优茶产区茶叶重金属含量均低于国家标准限量,茶叶中Cd、Hg、Cu、Pb含量随土壤中Cd、Hg、Cu、Pb含量增大而增大,不同重金属在茶叶中的富集系数为Cd>Hg>Cu>Pb>Cr>As。

Research of Pollution and Enrichment of Heavy Metal in Soil and Tea in Typical Tea Producing Areas of Guizhou Province

Samples of tea and soil were collected in three typical tea-producing areas in Guizhou province,and concentrations of heavy metals in soil and tea were detected.The results show that: the main polluted elements in tea-producing areas of Guizhou Province are Cd and Hg.The excessive rate of Cd in soil is highest in Meitan tea-producing area,which reach 39.4%.And Duyun tea area has the highest excessive rate of Hg,which is 24.2%.The average concentration of Cd in soil shows that Duyun tea area>Meitan tea area>Yunwu tea area,and the exceeding rate shows Meitan tea area>Duyun tea area>Yunwu tea area.The concentration and excessive rate of Hg shows Duyun tea area>Meitan tea area>Yunwu tea area.And also,the concentrations of heavy metals in tea are all below the national standard limits.The concentrations of Cd,Hg,Cu and Pb in teas increase with that increase in soils.The enrichment factor of heavy metals in tea shows Cd>Hg>Cu>Pb>Cr>As.