不同污染浓度的五种重金属在胡萝卜与土壤中的积累研究

Study on Accumulation of Five Heavy Metals in Carrots and Soil in Different Levels

土壤重金属污染不仅限制了经济、社会可持续发展,而且给人类健康带来威胁。了解和探明重金属在作物可食部分的累积情况和对产量的影响程度有着重要的意义。在海南最具有代表性的砖红壤中添加不同重金属含量的的5种重金属后,分析Cr、Pb、Cd、As和Hg在胡萝卜、土壤中的重金属含量,测定每种重金属添加后的胡萝卜产量,旨在揭示不同重金属添加量在大田下胡萝卜可食部分内和土壤中的累积规律及其对产量的影响,为治理重金属对胡萝卜的污染提供科学依据。研究结果表明:在不同重金属处理下,胡萝卜对5种重金属的吸收富集能力顺序为:Cd>Hg>Cr>As>Pb。不同重金属添加量的As、Hg、Cd、Pb、Cr在土壤中的有效态含量、全量随着处理浓度的升高而升高。收获胡萝卜后的土壤中随着元素浓度增大,对比空白都表现出减产的趋势,减产幅度由大到小为Cr>Pb>Cd>As>Hg。As、Pb、Cr对胡萝卜产量影响的差异不显著。其中,C1处理下的Hg使胡萝卜的产量显著上升,但C1、C2处理下的Cd分别使胡萝卜产量显著下降5.2%和15.7%。

Soil heavy metal pollution has not only restrict the sustainable development of economy and society, but also bring severe risk to human health. There is importantly significance to learn the accumulation of crops＇ edible part and the effect on crop＇ s yields. In thesis, heavy metals （Cr, Pb, Cd, As and Hg） concentrations in carrots and according soil （latosol） were investigated in a field experiment to ex- plore their accumulation in CaITOtS＇ edible parts and effect on yields, which can provide scientific evidences for soil pollution abatement. The main results of the study are shown below. Under different metal-specific treatments, the bioconcentration capacity of carrot to five metals fol- lowed in orders ： Cd 〉 Hg 〉 Cr 〉 As 〉 Pb. Heavy metal concentrations in carrot edible part increased with the raising of feed metal, respec- tively. After harvest, available-metal and total metal concentrations in carrot soil increased with the addition of heavy metal level, respective- ly. In general, reduced amplitude of the carrot yields followed the orders ： Cr 〉 Pb 〉 Cd 〉 As 〉 Hg. As, Pb and Cr treatments have no signifi- cant influence on the carrot yields. In the C1 level Hg treatment, compared with the control, the carrot yields increased by 7.8%. While in the C1 and C2 level Cd treatments, the pakchoi yields were reduced by 5.2% and 15.7%, respectively.