A Comparative study on evaluation of efficiency of EDTA, citric acid and salicylic acid chelating agents in phytoremediation enhancing of two ornamental plant species for elimination of Cr(III) and Cu(II) from contaminated soils

Phytoremediation is a new technology for remediation of contaminated soils, this study was conducted to evaluation of efficiency of EDTA, citric acid and salicylic acid chelating agents in phytoremediation enhancing of Amaranthus caudatus and Tagetes patula for elimination of Cr(III) and Cu(II) from contaminated soils in 2018.

After soil pots contaminating by 50 and 100 (mg/kg) K2Cr2O7 and 200 and 400 (mg/kg) CuSO4 salts, and 2.5 (mmol/kg) of EDTA and citric acid (CA) and 2.0 (mmol/kg) of salicylic acid (SA) solution treating, the cultured seedlings were harvested after 60 days. Then, after seedlings digestion, Cr and Cu contents were determined using ICP-OES

Based on the results obtained, the maximum contents of Cr (mg/ kg) in cultivated soil, root and stem samples of A. caudatus were 2.40, 5.18 and 1.86 were found in the SA, EDTA and EDTA treatments, respectively and in T. patula with 2.74, 6.00 and 1.30 were found to be in the SA, EDTA and EDTA treatments, respectively. Also, the maximum contents of Cu (mg/kg) in cultivated soil, root and stem samples of A. caudatus with 6.74, 3.77 and 3.34 were found to be in the SA, SA and EDTA treatments, respectively and in T. patula with 6.65, 3.45 and 9.50 were found to be in the SA, EDTA and EDTA treatments, respectively. On the other hand, translocation (TF) and bioconcentration (BCF) factors of A. caudatus both were greater than 1 in soils with 100 mg/kg added K2Cr2O7 containing CA, which indicates that this species can be known as hyperaccumulator of Cr

In conclusion, concerning to the considerable role of organic acids in soil refining electrokinetic and phytoremediation efficiency enhancing, using of these soil amendment agents is recommended to cleanup of contaminated soil with heavy metals