Study of the Bioleaching and Dissolution Kinetics of Zinc from a Zinc Secondary Source Using Indigenous Acidothiobacillus Ferrooxidans

Abstract

The increasing global demand for zinc has led to rapid depletion of its primary sources. Bioleaching, a sustainable and eco-friendly technology, offers a promising solution for metal recovery from secondary source. This study investigates the bioleaching of zinc from a secondary source, being a zinc-rich dumpsite, using indigenous acidithiobacillus ferrooxidans. The effects of pH, temperature, inoculum percentage and agitation speed on zinc dissolution were assessed. The results showed that optimal bioleaching conditions were pH 2.5, temperature 30°C, 20% inoculum and agitation speed 150 rpm with a maximum bioleaching of 75.5%. The dissolution kinetics using the shrinking-core model followed a mixed control; the reaction kinetics followed a first-order model, with an activation energy requirement (Ea) of 468.261 J/mol. The indigenous A. ferrooxidans strain demonstrated high performance and metal tolerance. This study highlights the potential of bioleaching for zinc recovery from secondary waste, contributing to economy sustainability and reduced environmental pollution.