A novel eco-friendly hybrid approach for recovery and reuse of copper from electronic waste

Abstract

Amid the plethora of initiatives and regulations targeting the minimization of electronic waste generation and its transboundary shipment, efforts to adopt a sustainable resource conservation from this emerging waste stream are considerably missing. Present study is a pioneer effort to develop a novel two stage biorecvoery process followed by electrochemical treatment to recover copper in its reusable form from waste printed circuit board. An isolated strain USCT-R010 was employed for the leaching of copper and process parameters (reaction pH, substrate concentration, inoculum size, pulp density, agitation speed) were optimized in order to maximize bioleaching of copper. The leach liquor containing mobilized copper was subjected to purification step where biosorption was carried out using dead biomass of Aspergillus oryzae and Baker’s Yeast under optimized reaction condition. Desorption was performed using 0.1N HCl to recover pure copper from dead biomass and more than 86% copper was desorbed from both the biosorbents. Electrowinning was carried out at current: 2A and electrolysis time: 150 min to recover 92.7% Cu from eluate. Characterization studies suggested 95.2% purity of recovered copper which was reused as an antibacterial agent against Escherichia coli. Utilization of low cost biomaterial for recovery and purification of metals, eco-efficient technology with high level of purity, reusability of recovered copper and environmentally sound practices are the aided incentives associated with this novel approach. The proposed work can be reckoned as successful demonstration of ‘Greening the waste’ concept in order to generate substantial economic, environmental and social benefits from e-waste.