添加螯合剂诱导-栽培红叶菾菜(Beta vulgaris var. cicla L.)修复铅和镉污染土壤效果的研究

Remediation of Lead and Cadmium Contaminated Soil with Chelate-Induced-Beta Vulgaris Var. Cicla L.

  • 摘要: 以雄安新区安新县重金属污染农田土壤为供试土壤,以Cd超积累植物红叶菾菜(Beta vulgaris var. cicla L.)为供试植物,设置不同浓度EDTA和柠檬酸(0,2.5,5,7.5,10 mmol kg−1)处理进行盆栽试验,探究螯合诱导-红叶菾菜修复Cd、Pb污染土壤的可行性。结果表明:(1)与对照相比,添加EDTA螯合剂使红叶菾菜生长及生物量均受到抑制,一定浓度柠檬酸处理能显著促进植物生长,5 mmol kg−1柠檬酸处理对植物株高、茎粗及生物量与对照相比的上升比例分别为4.52%、44.07%和50%;(2)添加EDTA螯合剂后土壤中Cd、Pb有效态含量相比对照分别提高了108.61% ~ 235.39%、67.98% ~ 224.16%,柠檬酸处理后土壤Cd、Pb有效态含量最大提高了180.07%、186.01%,EDTA对土壤重金属的活化效率显著高于柠檬酸;(3)通过对红叶菾菜地上部Cd、Pb含量及富集系数比较发现,EDTA更能促进红叶菾菜对Pb的吸收,柠檬酸更能促进红叶菾菜对Cd的吸收;(4)螯合剂处理后土壤中铵态氮、有效磷、速效钾含量显著增加。就本文试验条件、供试材料而言,螯合诱导-红叶菾菜修复铅镉复合污染土壤是可行的。

     

    Abstract: In order to clarify the feasibility of chelate-induced-leaf beet (Beta vulgaris var. cicla L., a hyperaccumulator for Cd) to the remediation of cadmium (Cd) and lead (Pb) contaminated soil, different concentrations of EDTA and citric acid (0, 2.5, 5, 7.5, 10 mmol kg−1) were added to soil collected from farmland of Anxin, Xiong'an New District in a pot experiment. The results showed that: (1) Compared with the control, the addition of EDTA chelating agent inhibited plant growth and biomass, while the citric acid treatment at a certain concentration significantly promoted plant growth. The addition of 5 mmol kg−1 citric acid increased plant height, stem diameter and biomass by 4.52%, 44.07% and 50% (2) The concentrations of available Cd and Pb in soil were increased by 108.61%-235.39% and 67.98%-224.16% after the addition of EDTA chelating agent, and by 180.07% and 186.01% after the addition of citric acid, respectively. The activation efficiency of EDTA on soil heavy metals was significantly higher than that of citric acid. (3) EDTA promoted the absorption of Pb, while citric acid with a certain concentration promoted the absorption of Cd by Beta vulgaris var. cicla L. (4) Ammonium nitrogen, available phosphorus and available potassium were increased significantly after treatment with chelating agent, which showed that soil fertility was not negatively affected. Our study indicated that chelate-induced-Beta vulgris var. cicla L. was practical in the remediation of Pb-Cd contaminated soil.

     

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