海南土壤中Zn、Pb、Cu、Cd四种重金属含量及其生物有效性的研究

RESEARCH ON HTE TOTAL BIOAVAILABLE CONCENTRATIONS AND BIOABAILABILITY OF Zn, Pb, Cu and Cd IN SOILS IN HAINAN PROBINCE

对海南63个土壤样品中的Zn、Pb、Cu、Cd四种重金属的总量和生物有效态含量以及45个植物样(根、茎、叶)中的重金属含量分别进行了测定,采样点基本上覆盖了海南全省,测定结果表明,土壤中Zn总量低于全国平均值,而Pb、Cu、Cd高于全国平均值,土壤中重金属生物有效态含量一般低于其总量的10%,其中Pb最高为7.71%,而Cu仅为1.13%,具有较大的变异性;植物中重金属含量与土壤中重金属总量呈现负相关性,但与土壤中有效态重金属含量一般呈现正相关性,叶中的重金属含量与土壤中有效态重金属含量之间的相关性更为显著,叶中的重金属含量与土壤中有效态重金属含量之间的相关系数分别为:Zn(0 726),Cu(0 626),Pb(0 774),Cd(0 512)。这说明土壤中重金属总量并不能全面的评价土壤的环境效应和重金属的生物有效性,应该把重金属总量和生物有效态含量结合起来加以研究,并应将土壤中重金属的含量与植物中该元素含量之间作相关分析,根据其相关系数的大小来判断其生物有效性的程度。

Total concentrations and bioavailability of Zn, Pb, Cu and Cdwere measured for 63 soil samples from Hainan Province, and the total concentrations were also measured of 45 plant samples segmented into stem, leaf and root. The study covers the whole province. The experimentresults showed that the total concentrations of Pb, Cd and Cu exceed the correspondingstatistical data of the whole country, but in contrary to Zn. The bioavailable concentrations are usually below 10% of the total concentrations, with the maximum up to 7.71% for Pb,while Cu has the lowest percentage,1.13%, which shows obvious variability. There exist significantlynegative correlations between the total heavy metal concentrations of soil samples and those ofsamples. On the contrary, the significantlypositive correlations were found between the total heavy metal concentrations of plant samples and the bioavailable metal concentrations of soil samples, the correlations are more positive between the above dataforleaves and soils. The Pearson correlation coefficients between the bioavailable metal concentrations ofsoil samples and the total concentrations ofplant samples are as follows: (Cu (0.626),) (Pb (0.774),) (Zn (0.726)) and (Cd (0.512)). This indicates it is necessary to study the bioavailabilityand total heavy metal concentrations ofsoils, and also to make acorrelative analysis between the heavy metal concentrations ofsoil samples and those of plant samples to assessbioavailability and environmental effects of the heavy metals in soils.