Abstract Description

The mining industry plays a significant role in the global economy through its provision of metals for various industries. Traditional mining practices have produced significant metal-containing wastes, especially in the form of mine tailings which pose serious risks to human, animal and environmental health through the formation of leachates. These mine tailings also represent an opportunity to develop technologies that mitigate the impacts of mining waste while also recovering valuable metals. This study investigated the use of microbial fuel cells (MFCs) as an environmentally sustainable and cost-effective method for reclaiming metals from mine tailings and power generation. Copper, iron, and cobalt are the key metals that were identified from a supplied mine tailings sample of cobalt ore slurry. Electroanalysis (cyclic voltammetry and linear sweep voltammetry) were used to examine the redox behaviour of copper(II), iron(II), and cobalt(II) under acidic conditions as a preliminary study of their suitability for MFC-based metal reclamation. The predicted reduction order was cobalt(III) followed by iron(III) and then copper(II). Cobalt(III) and iron(III) were both generated anodically during voltammetry and were reduced under the test conditions, however their divalent forms showed no further reduction peaks. The biological performance of Enterobacter cloacae and Serratia liquefaciens as inoculants in MFCs was evaluated and found to be comparable. Scanning Electron Microscopy/Energy Dispersive Spectroscopy (SEM/EDS) analysis confirmed metal accumulation on both cathodes and anodes after MFC operation. The study highlights MFCs as a promising technology for application in managing mine waste, offering a dual benefit of transforming hazardous waste into energy and reusable resources.