Feasibility of using Achillea wilhelmsii and Cardaria draba for biomonitoring and bioremediation of heavy metals (Zn, Pb and Ni) in the roadside environments

Monitoring of traffic emissions is a good way to build a safe ecosystem for living organisms. Therefore, the present study was conducted to assess the feasibility of using Achillea wilhelmsii and Cardaria draba located along the suburban roads of Hamadan for Zn, Pb and Ni removal by their aerial and underground organs in 2020.

In this descriptive study, after selecting 3 sampling stations, a total of 126 plant samples and 63 soil samples were collected. In the laboratory, the samples were prepared, and were then digested with acid. Subsequentely, the concentration of each heavy metal was measured by inductively coupled plasma-optical emission spectroscopy (ICP-OES). Moreover, bioconcentration factor (BCF), bioaccumulation factor (BAF), transfer factor (TF) and metal accumulation index (MAI) were also calculated. Statistical analyses of the results were performed using SPSS statistical software.

The mean values of BCF and BAF in both A. wilhelmsii and C. draba for all tested elements were greater than 1. On the other hand, A. wilhelmsii showed TF greater than 1 for zinc while C. draba showed TF greater than 1 for zinc and lead. The highest mean values of MAI in unwashed and washed shoots and roots of A. wilhelmsii were 98.48, 64.87 and 72.38, respectively.

Based on the calculated average values of BCF, BAF and TF of each elements, it can be argued that A. wilhelmsii and C. draba species have the potential of phytoextraction and Phytostabilization of the measured heavy metals and can be used for biomonitoring and bioremediation from soil and air in the heavy metals polluted areas.