不同改良剂对小青菜中镉和铅含量的降低效果

Effects of different amendments on reducing concentrations of Cd and Pb in Brassia chinensis L.

【目的】探讨不同改良剂对降低重金属污染土壤中小青菜镉、铅含量的效果。【方法】以小青菜品种"塌地乌"为试材,采用盆栽试验,设置施用不同改良剂(石灰、沸石、骨粉、FeS2、纳米羟基磷灰石、粉煤灰及其两两组合)处理,测定重度镉(40mg/kg)、铅(1 200mg/kg)污染土壤中小青菜生物量、镉和铅的吸收量、转运系数及土壤pH值,分析不同改良剂处理对小青菜中镉铅含量的降低效果。【结果】施入改良剂后,小青菜的生物量均有不同程度提高,其中,沸石+纳米羟基磷灰石处理下的生物量最大,与未施改良剂的对照相比增产51.1%(P<0.05)。小青菜地上部镉含量降幅最大的为石灰+沸石处理;地上部铅含量降幅最大的为沸石+骨粉处理。小青菜中镉的转运系数大于铅,表明镉比铅更容易迁移到小青菜地上部分。施入改良剂后,土壤pH值显著升高,且以沸石+骨粉处理下的pH值最大。【结论】施用改良剂后,小青菜中镉和铅的含量虽有不同程度降低,但仍超过国家食品卫生标准。

[Objective] The study was intended to explore the effectiveness of different amendments on reducing concentrations of Cd and Pb in Brassia chinensis L. planted in soil polluted by heavy metals. [Method] Using wuta-tsai as the material,a pot experiment was carried out to observe the yield and the absorption of Cd and Pb, transfer coefficient, and soil pH responses to different amendments（lime,zeolite, bone mill,FeSe ,nano hydroxyapatite, bottom ash and their combinations）applied in soil severely polluted by heavy metals（Cd 40 mg/kg,Pb 1 200 mg/kg）. Then the reductions of Cd and Pb contents in wuta-tsai were analysed. [Result] The biomass yield of wuta-tsai increased after application of amendments. The treatment of zeolite and nano hydroxyapatite co-application showed the highest yield with an increase of 51. 1%（P〈0.05）comparing to control group. Lime and zeolite co application dec effectively in the shoot of wuta-tsai, whilst zeolite and bone mill co-application was The transport coefficient of Cd in wuta-tsai was higher than the Pb, which explain to the shoot of the wuta-tsai easily mendments application and the highest occ reased Cd concentration efficient at blocking Pb. es that Cd can be moved than Pb. The soil pH value was increased significantly after a urred when using the treatment of zeolite and bone mill co-appli cation. [Conclusion] The study suggested that the content of Cd and Pb could be reduced with application of amendments,but the content of heavy metals of Brassia chinensis L. planted soil severely polluted by Cd and Pb was still higher than the national food standards.