吊兰对水体铅污染的耐性和吸收特性研究

选用观赏植物吊兰进行漂浮栽培实验,研究吊兰对水体铅污染的耐性和吸收特性,以期为铅污染废水修复过程中人工湿地植物的选择提供依据。结果表明,在2个测定期内(21、42d)吊兰的鲜重增量、株高、新增根数、最长根长、过氧化氢酶(CAT)和超氧化物歧化酶(SOD)活性随铅处理浓度的升高,表现为先升高后下降的趋势;可溶性蛋白质含量呈上升趋势;丙二醛(MDA)水平变化不显著;叶的富集系数逐渐减小;在水体铅污染物浓度达到50mg/L时,吊兰根部对铅的富集系数最大。总体上,随着处理时间的延长,吊兰的鲜重、株高、根数和最长根长、CAT活性略微升高,SOD活性、可溶性蛋白含量显著升高,根部富集系数减小,叶富集系数增大。本研究结果显示,吊兰是一种对铅具有极大耐性的植物,可以用于高浓度铅污染水体的修复。

Tolerance and uptake ability of Chlorophytum comosum in Pb-polluted water

The capacity of uptake and tolerance of Chlorophytum comosum(C.comosum) in Pb-polluted water body was investigated through the experiment of floating culture.It is expected to serve as a resource guide on selection of constructed wetlands plants in the restoration of lead-bearing wastewater.The experiment results showed that increment of fresh weight and roots,the plant height,the maximum root length,the catalase(CAT) and superoxide dismutase(SOD) activity increased first and then decreased,according to two different testing periods (21 and 42 d) in the experiment.There was no obvious change in the level of the content of malondialdehyde(MDA) with increasing concentrations of medium Pb,while soluble protein content increased continually.When Pb²⁺ concentration was 50 mg/L,the roots of C.comosum had the highest enrichment coefficients,however,the shoots of C.comosum of the enrichment coefficients dropped continually with elevated concentrations of lead.In brief,the fresh weight,the plant height,the numbers of roots,the maximum root length and catalase activity increased slightly with the increase of duration of stress,while the superoxide dismutase activity and soluble protein content were significantly elevated.Simultaneously,the enrichment coefficients of the roots of C.comosum decreased,yet the enrichment coefficients of shoots increased.The results revealed that C.comosum has a powerful potential in being used in the repair of high concentrations of lead-containing wastewater due to its excellent performance of uptake and tolerance for Pb.