垂序商陆对污染水体重金属去除潜力的研究

摘要

以超积累植物垂序商陆为实验材料,通过温室实验,探讨其应用于污染水体的植物修复潜力.选取生长一致的垂序商陆幼苗置于不同重金属水平(Mn2+,Zn2+和Cd2+)的生长介质,分别在0,2,4,6,8和10 d测定溶液中的重金属含量;10 d后收获垂序商陆,并将植株分为地上部和根系,用原子吸收法测定植物不同部位的重金属含量.研究结果表明:10 d内垂序商陆对Mn2+,Zn2+和Cd2+的去除率分别为35.4%～49.7%,38.1%～40.0%和50.8%～53.7%;在不同条件下垂序商陆体内重金属含量不同,但均随着生长介质中重金属水平的提高而上升;垂序商陆地上部分锰含量较高,而锌和镉则主要吸附在根系;垂序商陆对水体重金属的去除能力表现为植株吸收和根系吸附作用的复合;利用垂序商陆种苗实施低浓度重金属废水的植物修复具有广阔的应用前景.%A greenhouse study was carried out to explore the potential of Phytolacca americana for removal of heavy metals from contaminated waters. The uniform seedlings for each treatment group were selected and grown on the nutrient solution supplemented with Mn2+, Zn2+ and Cd2+ of different concentrations. The metal concentrations in solution were determined at 0, 2, 4, 6, 8 and 10 d, respectively; and after 10 d cultivation, the metal concentration was determined in the plant using an atomic absorption spectrophotometer. After 10 d of the experiment, metal contents of Mn2+, Zn2+ and Cd2+ in solution decreases by 35.4％-49.7％, 38.1％-40.0％ and 50.8％-53.7％, respectively. Concentrations of heavy metals in shoots and roots ofphytolacca americana Linn all increase progressively with the increase of supply level. Mn contents in shoots are invariably greater than those of Zn and Cd. Zn and Cd are mainly from the adsorption of roots.Thus the ability of phytolacca americana Linn to remove heavy metals from contaminated waters results from plant uptake and root adsorption. These results confirm that Phytolacca americana has great potential for removal of heavy metals from contaminated waters.