废料碳酸钙对低累积作物玉米吸收重金属的影响:田间实例研究

通过田间试验方法,研究了在铅锌矿废水污染的土壤上施用废料碳酸钙对第1、2季低累积玉米(Zea mays)产量以及重金属Cd、Pb、Zn和Cu含量的影响,并分析了施用废料碳酸钙后土壤pH和土壤有效态重金属含量的变化。结果表明,施用废料碳酸钙,玉米产量均有显著提高,其中高量废料碳酸钙处理效果最佳,第1季增产154%,第2季增产275%,玉米对Cd、Zn和Cu吸收量降低,玉米籽粒Cd、Zn和Cu含量降低到了国家食品卫生标准允许的含量水平。与对照比较,废料碳酸钙不同用量水平均能不同程度地提高土壤pH,降低土壤有效态重金属含量,并抑制茎叶Cd和Cu向玉米籽粒的转移,从而造成玉米籽粒重金属含量降低。

EFFECT OF WASTE-CaCO3 ON HEAVY METALS UPTAKE OF LOW-ACCUMULATING MAIZE: FIELD STUDY

Field experiments were carried out to study the effects of waste-CaCO3 application on the growth and heavy metals (Cd, Pb, Zn, Cu) concentration of low-accumulating cultivar of Zea mays with two harvests on a soil contaminated by waste water of lead/zinc mine. Changes of soil pH and available heavy metals content induced by waste-CaCO3 application were also investigated. Results showed that the waste-CaCO3 addition significantly increased the biomass yields of Z. may . The yields of corn with the high level application of waste-CaCO3 were the highest, increased by 137% for the 1st harvest and 275% for the 2nd harvest comparing with the control. The concentration of heavy metals (Cd, Pb, Zn, Cu) in grain and stem of Z. mays were decreased by waste-CaCO3 application. According to Chinese standards of foods, the concentrations of Cd, Zn and Cu in grain of Z. mays were below the standard limit. Compared to the control, the waste-CaCO3 addition increased soil pH and reduced the concentration of available heavy metals in soil. It was found that the transportation of Cd and Cu from stem to grain in Z. mays were limited with waste-CaCO3 addition, resulting in the reduction of heavy metals in grains of Z. mays.