College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, PR China; College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, PR China.
College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, PR China.
Sci Total Environ. 2019 Oct 10;686:476-483. doi: 10.1016/j.scitotenv.2019.05.330. Epub 2019 May 23.
Nowadays, the problem of heavy metal pollution in vegetables is received wide attention. In this work, attapulgite clay (ATTP), as a cheap and readily available inorganic mineral material, was modified with nano zero-valent iron (nFe@ATTP) for heavy metal immobilization in soil. Batch experiments were employed to evaluate the optimal remediation performance by ATTP before and after modified with nFe through planting Pakchoi (Brassica chinesis L.) in Cd, Cr, and Pb contaminated soil from Changsha. The results showed that amendments can all increase the pH value of soils, and notably decrease the concentration of extractable Cd, Cr, and Pb in soil. The germination rate and root length of Pakchoi were promoted, and the activities of peroxidase (POD), catalase (CAT), and malondialdehyde (MDA) contents were notably reduced besides superoxide dismutase (SOD) activity after treatments with ATTP and nFe@ATTP. Vicia faba-micronucleus test indicated that the application of amendments reduced the toxicity of heavy metals on the genetic material of Vicia faba root tip cells. The nFe@ATTP were found to well convert Cd, Cr, and Pb into less bioavailable state in soil, thus blocking heavy metal uptake by plants. This material could be a promising amendment for heavy metals contaminated soil.
如今，蔬菜重金属污染问题受到广泛关注。在这项工作中，凹凸棒石粘土（ATTP）作为一种廉价易得的无机矿物材料，经过纳米零价铁（nFe@ATTP）改性，用于土壤中重金属的固定。通过在长沙受镉、铬和铅污染的土壤中种植白菜（ Brassica chinesis L.），采用盆栽实验评价了改性前后 ATTP 的最佳修复性能。结果表明，改良剂均能提高土壤 pH 值，显著降低土壤中可提取态 Cd、Cr 和 Pb 的浓度。ATTP 和 nFe@ATTP 处理后，白菜的发芽率和根长均得到促进，超氧化物歧化酶（SOD）活性显著提高，而过氧化物酶（POD）、过氧化氢酶（CAT）和丙二醛（MDA）含量降低。蚕豆微核试验表明，施用改良剂降低了重金属对蚕豆根尖细胞遗传物质的毒性。nFe@ATTP 能有效地将 Cd、Cr 和 Pb 转化为土壤中生物利用性较低的状态，从而阻止重金属被植物吸收。该材料可能是一种有前途的重金属污染土壤改良剂。
