土壤重金属污染背景下的任豆修复试验

为寻找适合矿业尾矿坝人工生态恢复的植物,以广西南丹长坡矿堆存50a之久的尾矿坝为背景,通过盆栽模拟,运用室内土培和水培两种试验方法,研究了不同矿土比例(尾矿样与泥土比例分别为5∶0、4∶1、3∶2、2∶3、1∶4、0∶5)以及不同浓度(0、2.5、5、10、25、50、100、150、200、250mg·L-1)Pb2+、Cu2+、Zn2+在任豆苗体内的吸收、积累和分布的动态变化规律。结果表明,任豆对Pb、Cu、Zn都具有一定的吸收能力,任豆幼苗可以在一定的重金属胁迫环境下存活,任豆对重金属Pb的耐性最大,在高浓度下依然可以存活。任豆对不同类型的重金属的吸收及转运能力存在较大差异,从任豆对Pb、Cu、Zn的转运能力来看,任豆并非这3种重金属的超累积植物。试验表明,任豆在矿业尾矿坝的人工生态恢复(植物修复)中有一定的应用价值,但能否大规模采用任豆作为尾矿坝的生态修复物种,尚需进一步研究验证。

Repair Experiment of Heavy Metal Polluted Soil with Zenia insignis

In order to find plants of manual and ecological restoration and phytoremediation which is suitable to tailings mine dams so as to carry out the ecological restoration of vegetation effectively, this paper dealed with different proportions of mineral soil (the proportion of core sample and normal soil is 5:0, 4:1, 3:2, 2:3. 1:4 and 0:5 respectively) and the dynamic transformation disciplinarian of absorption, accu-mulation and distribution of different concentrations (0, 2.5, 5, 10, 25, 50, 100, 150, 200, 250 mg·L~(-1))Pb~(2+), Cu~(2+), Zn~(2+) in the body of Zenia insignis with the background of tailings mine dams which is piled-up for 50 years in Nandan, Guangxi. This experiment was carried out with the method of statuaries simulation. and other two comparative method of hydroponics and soil culture indoors. The results indicated that : Zenia insignis had the capacity to absorb the heavy metals Pb, Cu, Zn, the amount of heavy metals accumulated in the body of Zenia in-signis was related with the types and environment of heavy metals. Zenia insignis could survive in the environment of certain heavy metal stress. Zenia insignis had the best endurance to heavy metal Pb which could still survive in high concentration. There was significance differ-ence in the ability to absorb and transfer different types of heavy metals. From the aspect of the transfer ability of the three heavy metals, Zenia insignis was not the hyper-accumulator of the three heavy metals, but Zenia insignis was of great significance in the manual and ecological restoration and phytoremediation of tailing mine dams. However, it should be further studied on whether it is possible to employ Zenia insignis as the species of ecological restoration of tailings mine dams in Nandan.