Studies on phytoremediation of chromated copper arsenate (CCA) using Acacia plant species (Fabaceae)

Soils contaminated with elevated levels of toxic heavy metals affect the soil quality. Phytoremediation is one of the constructive methods used in the mitigation of toxic metals from the soil. A pot experiment was performed by application of eight different concentrations of CCA viz 250, 500, 750, 1,000, 1,250, 1,500, 2,000, and 2,500 mg kg^-1 soil to evaluate the efficiency of Acacia mangium and Acacia auriculiformis in phytoremediation of CCA compounds. Results showed that the shoot and root length, height, collar diameter, and biomass of the seedlings were significantly reduced with increase in CCA concentrations. The roots of the seedlings accumulated 1.5- to 2.0-fold higher amounts of CCA than in stem and leaves. The amount of Cr, Cu, and As found in the roots of A. mangium and A. auriculiformis at 2,500 mg CCA were 10.01 and 10.13, 8.51 and 8.84 mg, and 0.18 and 0.33 mg g^-1, respectively. Similarly, the amount of Cr, Cu, and As found in stem and leaves were 4.33 and 7.84, 3.51 and 6.62, and 0.10 and 0.11 mg g^-1, respectively. The quantity of Cr, Cu, and As found in stem and leaves were 5.95 and 9.00, 4.86 and 7.18, and 0.09 and 0.14 mg g^-1, respectively. Overall, the present study advocates potential use of A. mangium and A. auriculiformis in phytoremediation of Cr, Cu, and As contaminated soils.