李氏禾修复重金属(CrCuNi)污染水体的潜力研究

The Ability of Leersia Hexandra Swartz to Remediate Heavy Metals(Cr, Cu, Ni) Contaminated Waters

李氏禾(Leersia Hexandra Swartz)是中国境内发现的第一种铬超富集植物。通过水培实验,评价了李氏禾对水中Cr、Cu、Ni的去除潜力。结果表明,李氏禾能够有效去除水体中的Cr、Cu、Ni污染物,重金属初始浓度分别为10和20mg·L-1的营养液,10d后Cr浓度降低到原子吸收分光光度法检出限以下,10d后Cu浓度降低到1.02mg·L-1和1.25mg·L-1,20d后Ni浓度降低到1.10和2.14mg·L-1。收获的植物根、茎、叶中重金属含量均较高,根中重金属含量显著高于茎、叶。单株生物量的比较结果表明,含Cr培养液中生长的李氏禾生物量与对照相比无显著减少(P>0.05),含Cu、Ni营养液中生长的李氏禾生物量均显著低于对照(P<0.05),表明李氏禾对Cr的耐性强于Cu和Ni。李氏禾适宜于湿生环境中生长,能对多种重金属产生大量富集,对Cr、Cu、Ni等重金属污染水体的修复表现出较强的潜力。

Leersia Hexandra Swartz is the first Cr-hyperaccumulator discovered in South China （Guangxi Zhuang Autonomous Region ）. The aim of this paper was to investigate the capacity of this species to remove Cr, Cu and Ni from the contaminated water. Hydroponic experiments were treated with Cr, Cu and Ni, each at the level of 10 mg·L^-1 or 20 mg·L^-1. After 10 days （20 days for Ni treatment ） of the experiment, Cr concentrations decreased below the detect limit, Cu concentrations decreased to 1.02 mg·L^-1 and 1.25 mg·L^-1, Ni concentrations decreased to 1.10 mg·L^-1 and 2.14 mg·L^-1 in the solutions with 10 mg·L^-1 treatments and 20 mg·L^-1 treatments respectively. The contents of heavy metals in plant tissues were high, especially in root. Biomass of L. Hexandra showed significant decrease with Cu and Ni treatments （P〈0.05）. However, significant decrease of blomass was not observed with Cr treatment （P〉0.05）. It indicated that this species possesses higher tolerance to Cr than to Cu and Ni. L. Hexandra Swartz also has remarkable accumulating capacity for Cu and Ni. So it is an excellent species for the remediation of heavy metals contaminated water.