Phytoremediation potential of native medicinal plant species in mining degraded soil of Mohmand Northwest Pakistan.

The phytoremediation efficiency of sixteen native medicinal plants was studied in soil degraded by mining in Mohmand, Northwest Pakistan. Elemental analyses of samples were carried out by using an atomic absorption spectrophotometer. The average values of soil pH (7.8), electrical conductivity (0.9 dS.m^-1), total soluble salts (0.29%), calcium carbonate (7.75%), organic matter (1.31%), nitrogen (0.65%), phosphorus (14.9%), and potassium (218%). The soil texture was loamy sand, and potentially toxic element (PTE) concentrations (mg.kg^-1) were Cd (3.45), Cr (1602), Cu (45.7), Pb (24.4), Mn (228.5), Fe (675.3), Ni (49.9), and Zn (392.5). The average mean concentration (mg.kg^-1) of PTEs in aerial and underground parts were Cd (2.2, 2.0), Cr (31.3, 30.9), Cu (45.7, 26.2), Fe (353.2, 311.5), Mn (294, 53.4), Ni (51, 9.3), Pb (8.5, 48.9), and Zn (25.6, 21.1), respectively. The bioconcentration factor (BCF) revealed that Cannabis sativa (1.0), Marrubium vulgare (1.1) and Chiliadenus glutinosus (1.7) for Cd; all plants for Pb except Ajuga integrifolia, Calotropis procera, Marrubium vulgare, and Peganum harmala have the phytostabilization efficiency. Mobility ratio (MR) of PTEs indicated that Satureja montana (1.6) for Cd and all plants for Mn and Ni except Lycopersicum esculentum, Marrubium vulgare, Pulicaria dysentrica, and Satureja montana tend to accumulate these PTEs in aerial parts. Pearson's correlation matrix revealed a moderate correlation between Cr - Pb (0.54) and Cu - Zn (0.52) and a significant correlation between Cd - Fe (0.80) and Mn - Ni (0.87). In conclusion, the majority of the medicinal plants studied demonstrated a strong capacity for phytoextraction, while some exhibited phytostabilization efficiency in the area.