Lead Accumulation Potential in Acacia victoria

Abstract

To assess the potential of Pb⁺² accumulation in different parts of Acacia victoria, one year old A. victoria seedlings were exposed to Pb²⁺(NO₃)₂ in 5 different concentrations: 0, 50, 250, 500 and 1000 (mg Pb²⁺ L⁻¹) for 45 days. Subsequently, Pb²⁺ uptake was quantified in roots, shoots and leaves of the seedlings by Atomic Absorption Spectroscopy (AAS). In addition, some physiological parameters such as biomass production, shoots and roots length, plant appearance, tissue concentrations and chlorophyll content were examined. Tissue concentrations increased as Pb²⁺ concentration increased for A. victoria. The visible toxicity symptoms (chlorosis and necrosis) appeared only to the highest concentration (1000 mg Pb²⁺ L⁻¹), resulting in photosynthesis decrease, plant height, root length and dry biomass reduction. Almost 70% (up to 3580 mg Kg⁻¹ of dry tissue) from the Pb²⁺ was accumulated in the entire plant tissues was retained in the roots in the seedlings exposed to 1000 mg Pb²⁺ L⁻¹. The seedlings accumulated between 403 to 913 mg Kg⁻¹ of Pb²⁺ in shoots and 286 to 650 mg Kg⁻¹ of Pb²⁺ in leaves at different treatments. Bioconcentration and translocation factors were determined 5.14 and 0.255, respectively. The results show that A. victoria is suitable for lead-phytostabilization in Pb²⁺-contaminated soil.

KEY WORDS:

• Acacia
• phytoremediation
• Phytostabilization
• lead-contaminated soil