Phytoremediation of heavy metal-contaminated soils: Natural hyperaccumulation versus chemically enhanced phytoextraction
Phytoremediation of heavy metal-contaminated soils: Natural hyperaccumulation versus chemically enhanced phytoextraction
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DOI：
10.2134/jeq2001.1919
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发表时间：
2001-11-01
影响因子：
2.4
通讯作者：
McGrath, SP
中科院分区：
文献类型：
--
作者：
Lombi, E;Zhao, FJ;McGrath, SP
通过盆栽试验，比较了两种植物修复策略：利用锌、镉超富集植物Thlaspi caerulescens J. Presl & C.使用玉米（Zea mays L.）用乙二胺四乙酸（EDTA）处理。该研究使用了工业污染土壤和被污水污泥中的金属污染的农业土壤。三茬T.生长391 d以上的铜绿假单胞菌对工业污染土壤中Cd和Zn的去除率分别超过8 mg kg（-1）和200 mg kg（-1），分别占土壤中Cd和Zn的43%和7%。而农业土壤中高浓度的Cu则严重抑制了T. caerulescens，从而限制了其植物提取潜力。EDTA处理大大增加了重金属在两种土壤中的溶解度，但这并没有导致在玉米芽中的金属浓度大幅增加。玉米+ EDTA对Cd、Zn的植物提取量远小于T.在工业污染土壤中，铜绿假单胞菌（Caerulescens）的活性最高，而在农业土壤中，铜绿假单胞菌（Caerulescens）的活性最低。EDTA处理后，土壤孔隙水中可溶性重金属主要以金属-EDTA络合物形式存在，并能持续数周。EDTA处理后土壤孔隙水中高浓度的重金属可能以地下水污染的形式构成环境风险。
A pot experiment was conducted to compare two strategies of phytoremediation: natural phytoextraction using the Zn and Cd hyper-accumulator Thlaspi caerulescens J. Presl & C. Presl versus chemically enhanced phytoextraction using maize (Zea mays L.) treated with ethylenediaminetetraacetic acid (EDTA). The study used an industrially contaminated soil and an agricultural soil contaminated with metals from sewage sludge. Three crops of T. caerulescens grown over 391 d removed more than 8 mg kg(-1) Cd and 200 mg kg(-1) Zn from the industrially contaminated soil, representing 43 and 7% of the two metals in the soil. In contrast, the high concentration of Cu in the agricultural soil severely reduced the growth of T. caerulescens, thus limiting its phytoextraction potential. The EDTA treatment greatly increased the solubility of heavy metals in both soils, but this did not result in a large increase in metal concentrations in the maize shoots. Phytoextraction of Cd and Zn by maize + EDTA was much smaller than that by T. caerulescens from the industrially contaminated soil, and was either smaller (Cd) or similar (Zn) from the agricultural soil. After EDTA treatment, soluble heavy metals in soil pore water occurred mainly as metal-EDTA complexes, which were persistent for several weeks. High concentrations of heavy metals in soil pore water after EDTA treatment could pose an environmental risk in the form of ground water contamination.