Electrokinetic removal of Cd, Ti, Pb, and Sb from abandoned and active artisanal gold tailings from Amansie West District of Ghana

This study explores the effectiveness of electrokinetic removal of heavy metals, such as Cd, Ti, Sb, and Pb from abandoned and active tailing soils among different soil fractions/phases. owing to the nature of the soil components in tailings, traditional methods may encounter various challenges that are ineffective. The aim of the study is to understand and address the distribution of heavy metals among tailing soil fractions (exchangeable, carbon, iron manganese oxide, organic/sulfide, and residual bound fractions) via electrokinetic remediation. The research was conducted in a 1215 cm³ electrochemical cell containing gold tailings via a continuous constant current of 1 A for five days. A platinum electrode served as the anode, and a titanium plate acted as the cathode. After five days, the remediation efficiency was assessed via aqua regia and sequential extraction methods. The findings showed lower metal removal efficiencies of the abandoned tailings (<5 %) than those of active tailing soil. This phenomenon could be attributed to the surface charge of the soil particles and the diffusion of metals into soil minerals resulting in the stabilization and occlusion of the the heavy metals into the nonavailable phases of the soil (organic/sulfide and residual bound fractions). In the speciation studies, Pb species were enriched mainly in the residual fraction. Antimony was also enriched in the residual, organic/sulfide bound, and Fe/Mn fractions. The Cd was associated with organic/sulfide and residual fractions, whereas Ti was enriched mainly in organic/sulphide fractions. The concentration of heavy metals in the active and abandoned tailing soils were comparable. The study concluded that electrokinetic remediation has the potential to remove harmful elements from abandoned and active tailings whiles providing insightful information on the physicochemical phenomena governing these processes.