Phytoremediation of Soils Contaminated with Cadmium by Agave americana

ABSTRACT

Agave americana was evaluated for its phytoremediation potential of the soils contaminated with Cd. This plant was selected because of its drought tolerance and high biomass. The pot culture experiment was carried with five levels of cadmium (0, 25, 50,100, and 200 mg Cd kg soil⁻¹). Parameters, viz. uptake, translocation factor (TF), translocation efficiency (TE), bioconcentration factor (BCF), etc., were calculated to study the phytoremediation potential. The study indicated that the plant was highly tolerant to Cd at lower levels, i.e., up to 50 mg Cd kg soil⁻¹, but there was a significant reduction in dry weight of root, leaf, and total at higher levels of, i.e.,, 100 and 200 mg Cd kg soil⁻¹. Cd mainly accumulated in the roots, and exclusion was found to be the principal physiological tolerance mechanism. Based on the tissue concentration of Cd (<100 μg g⁻¹ in the leaves; and TF and BCF <1), A. americana was classified as an excluder of Cd. However, since, the plant could establish an evergreen cover over the contaminated/polluted land surface because of its exponential reproductive capacity, it could be suitable for the phytostabilization of soils contaminated with Cd.

摘要

研究了龙舌兰对镉污染土壤的修复潜力. 该植物具有耐旱性强, 生物量高的特点. 采用5个镉水平 (0, 25, 50100和200mg-Cd-kg-soil-1) 进行盆栽试验. 计算了植物吸收, 转运因子 (TF), 转运效率 (TE), 生物富集因子 (BCF) 等参数, 研究了植物修复潜力. 研究表明, 在较低水平 (高达50mg Cdkg土壤-1) 下, 植株对Cd具有高度耐受性, 但在较高水平 (100和200mg Cdkg土壤-1) 下, 根, 叶和总干重显著降低. Cd主要在根中积累, 排除是主要的生理耐受机制. 根据叶片中Cd的组织浓度 (<100μg−1, TF&BCF<1), 美洲青蒿被归类为Cd的排除者. 然而, 由于该植物具有指数级的繁殖能力, 可以在污染/被污染的地表建立常绿覆盖层, 因此适合于Cd污染土壤的植物稳定化.

KEYWORDS:

• Agave americana
• bioconcentration factor
• cadmium
• phytoremediation
• translocation factor
• translocation factor

关键 字:

• 关键词:美洲龙舌兰
• 生物浓缩因子
• 镉
• 植物修复
• 易位因子
• 易位因子

Acknowledgments

The authors thank Dr A.K. Patra, the Director of the Institute for providing the facilities for conducting the experiment.

Disclosure statement

The authors declare that there is no conflict of interest.