近1000年浙江慈溪地区表层土壤重金属元素演化过程

Study on heavy metals evolution process in surface soil in recent 1000 years in Cixi city,Zhejiang province

为判别慈溪地区表层土壤重金属元素来源,采集该地区近1000年不同成土时期的表层土壤样品,分析各重金属元素的演化过程,结果发现除元素Hg含量随土壤年龄的增大而增加外,其他重金属元素的含量仅在成土285年处出现高值,随后又下降并趋于平缓。利用富集因子法分析演化过程中各重金属元素质量变化,发现其中元素As质量未变化;Hg质量一直增加,成土近1000年时其质量值是初始值的4.7倍;重金属元素Zn、Pb和Cd成土285年和近1000年时质量增加,而Cu、Ni和Cr成土285年时质量增加。

Using the different soil ages in recent 1000 years in Cixi city of Zhejiang province,where located about 10 nature plain beaches,the heavy metal element evolution processes were correctly identified in this study.Element Hg has a high correlation with time while other heavy metal elements have a high concentration value in soil age year 285 and subsequently become flat.Selecting Zr as immobile elements,it shows that As weight does not increase and Hg weight increases to more than 4.7 times of origin weight.The weights of heavy metal element Zn,Pb,Cd increase a little at year 285 and during recent 1000 years.At the same time,Cu,Ni,Cr weights have little increases at year 285 too.The additions are anthropogenic pollution so surface soil has been polluted by parts of heavy metal elements during podogenesis.The curve fitting models for each heavy metal element show a very good correlation except for Cr,Cd,As and Pb.Element Hg model reflects the significant process of human pollutions.