Chronological Variation of Metals in Reclaimed Coal Mine Soil and Tissues of Eucalyptus Hybrid Tree After 25 Years of Reclamation, Jharia Coal Field (India)

Fast-growing metal-accumulating woody trees are potential candidates for phytoremediation of coal mine overburden (OB) dumps. The present study assessed chronological variation in metals (Pb, Zn, Mn, Cu, and Co) concentration in reclaimed mine soil (RMS) and tissues (leaf, stem bark, stem wood, root bark and root wood) of Eucalyptus hybrid tree between 3 and 25-year old OB dumps (RMS3 and RMS25) from Jharia coal field (India). Total metal concentrations of Pb, Zn, and Cu in RMS25 were 1.55, 3.46, and 1.44 times lower (p<0.05), respectively, than RMS3. Higher concentrations of total (110%-565%) and available form (DTPA-extractable) of metals (109%-480%) were observed in RMS25 than in control soil. Pb selectively accumulated in stem bark, Zn and Mn in leaves, and Cu and Co in root wood. Metal concentrations were higher (1.04-4.15 times at p<0.05) in tree tissues growing on RMS25 than in RMS3. This study concluded that Eucalyptus hybrid could be utilized for reclamation of coal mine OB dumps.