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

Abstract

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.

NOVELTY STATEMENT

Phytoremediation of soils contaminated with heavy metals is well documented. Interestingly, information on the influence of Acacia tree species in remediation of chromated copper arsenate (CCA) is scanty. We found that the higher concentrations of CCA (1,000–5,000 mg) significantly reduced the seed germination, growth, and biomass of seedlings. Further, the results revealed that accumulation of Cr, Cu, and As were 1.5- to 2-fold higher in roots than in shoots. Present study adds knowledge on efficacy of Acacia mangium and Acacia auriculiformis in phytoremediation of CCA contaminated soils.

Keywords:

• Acacia species
• accumulation
• CCA
• growth indices
• phytoremediation
• seed germination

Acknowledgments

The authors are grateful to Bangalore University, Bengaluru, India for extending research facilities and also for constant encouragement.

Author contributions

BMR conceptualized and designed the study and executed the experiments. BMR and NN finalized the manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The authors confirm that the data and materials supporting the results of the study are available within the article.