单 位：
河南农业大学农学院;河南农业大学资源与环境学院
摘 要：
通过探究膨润土与褐煤单一及其复配对土壤中镉赋存形态及其对玉米各部位吸收镉的影响,为土壤镉污染修复的技术选择提供科学依据。采用盆栽玉米(Zea mays L.)试验,以河南济源某企业周边0～20 cm表层重金属污染土壤为研究材料,将膨润土(S)和褐煤(P)按照1. 5%、3%、5%的土壤质量比例单独及二者正交混合添加,利用BCR连续提取法,研究不同钝化剂处理对镉污染土壤的修复效应。结果表明:膨润土与褐煤不同比例混合施用可使玉米茎叶和根中镉质量分数分别降低22. 2%～49. 9%、9. 7%～40. 6%。膨润土与褐煤的单一及混合施用均可增加玉米的株高及地上部干物质量,降低玉米茎叶和根对镉的富集。钝化后土壤中镉的形态含量发生了变化,土壤中弱酸提取态镉会向着较为稳定的形态转化。膨润土单一施用对镉的钝化效果不显著;单独施用褐煤比单独施用膨润土效果好;膨润土和褐煤两者混合施用的钝化效果最好,可使土壤中弱酸提取态镉质量分数减少10. 4%～31. 1%。对于重金属镉污染的石灰性土壤,褐煤的修复效果整体优于膨润土,但两者结合使用效果更佳。
译 名：
Immobilization and remediation of Cd contaminated soil treated with bentonite,lignite and their mixture
作 者：
ZHANG Jingjing;ZHAO Yongqin;XU Liang;HUA Dangling;YANG Qiuyun;College of Resources and Environment,Henan Agricultural University;Collage of Agronomy,Henan Agricultural University;
关键词：
cadmium;;bentonite;;lignite;;immobilization and remediation;;Zea mays;;soil
摘 要：
[Background]In situ immobilization of heavy metal in contaminated soils with amendments decrease the bioavailability of heavy metals by changing occurrence state of heavy metals in soils,resulting from the reactions of dissolution/precipitation,exchange/adsorption,oxidation/reduction and organic complex. This method has been considered as an important and non-replaceable measure for heavy metal contaminated soil remediation. Natural materials and industrial by-products with high sorption characteristics can be used to the remediation of heavy metal contaminated arable soils,and different amendments have different effects on contaminated soils. Bentonite is a kind of clay mineral dominated by montmorillonite while lignite is rich in humic acid with very low cost. Most current studies use a single passivating agent,and few studies combine organic lignite and inorganic bentonite for heavy metal contaminated soil remediation. [Methods] Pot experiments were conducted to investigate the effects of bentonite(S) and lignite(P) on the occurrence state of cadmium in soils and the uptake of cadmium in different parts of maize growing in contaminated soils sampled from Jiyuan city,Henan province. The addition amounts of bentonite(S) and lignite(P) were 1. 5%,3%, and 5%respectively,and the mixture treatment was based on the orthogonal experimental design. BCR(European Community Bureau of Reference) sequential extraction method was used to assess the remediation effects of amendments on soils polluted by cadmium after incubation and seedling stage.[Results]The mixture of bentonite and lignite in different proportions reduced cadmium content in stem,leaf and roots by 22. 2%-49. 9% and 9. 7%-40. 6%,respectively. All the treatments,mixed addition or alone,increased plant height and dry biomass of aboveground part,and decreased the enrichment of cadmium in stem,leaf and roots in contrast to the CK. After immobilization and remediation,the content of cadmium extracted from weak acid in soil was converted to more stable forms. There was no significant difference by bentonite addition alone,while lignite alone significantly reduced the weak acid soluble content of soil Cd. The mixed treatment of bentonite and lignite worked well,and decreased the weak acid extractable content of soil Cd by 10. 4%-31. 1%. [Conclusions] Regarding the stabilization and remediation effect,lignite treatment worked better than bentonite treatment,and a combination for these two amendments worked the best,which may provide scientific basis for the safety utilization of calcareous soil polluted by cadmium.
