Phytoremediation Potential of E. camaldulensis and M. alba for Copper, Cadmium, and Lead Absorption in Urban Areas of Faisalabad City, Pakistan

Abstract

Soil pollution by heavy metals from industrial and anthropogenic activities is prevalent and a serious threat to ecosystems and humans. To immobilize heavy metal toxicity using trees is an effective and low-cost method for soil remediation. The present study was aimed to assess the most suitable bioindicator of trace elements including copper (Cu), cadmium (Cd), and lead (Pb) among Morus alba and Eucalyptus camaldulensis plant species at seven different sites in Faisalabad, an industrial city of Pakistan during the summer and winter seasons. Samples from the leaf, bark, deposited dust, and soil of both subjected species was collected for the assessment of metals accumulation. The recorded data showed that the trend of heavy metal concentration in soil, deposited dust, bark, and the leaf of both species was Pb > Cu > Cd. Generally, the maximum concentration of Cd, Cu, and Pb was recorded at the building material processing area during both seasons in both subjected species. Moreover, the highest concentration of Cd and Pb was recorded in leaf samples, while the highest concentration of Cu was recorded in dust samples. These results suggesting the idea that tree leaves can be used as a good indicator of Cd, and Pb concentration. In the case of Cu, a highly significant correlation (P < 0.05) was found between Cu concentration in deposited dust and leaves of both species during both growing seasons, indicating that the main source of Cu accumulation is atmospheric dust. Moreover, the summer season was more sensitive for the exposure of Cd, Cu, and Pb while, M. alba was proved as a good bioindicator and bioaccumulator for all recorded heavy metals during both seasons. According to the obtained results, M. alba trees are more likely to capture Cd, Cu, and Pb from the air, so planting these trees in industrial areas with such atmosphere pollutants would be beneficial.