Efficacy of Metal Extraction from Discarded Printed Circuit Board Using Aspergillus tubingensis

Abstract

The immense growth in the usage of electrical and electronic equipment (EEE) and their shorter lifespan are accelerating their discarding rate and the generation of waste EEE (WEEE) or electronic waste (e-waste). To conserve natural resources and to reduce adverse environmental impact, recycling of e-waste is getting wider attention worldwide. Printed circuit board (PCB) is an integral part of EEE. Recycling of e-waste especially PCB has become a major concern owing to its high metallic content including base, precious, and toxic metals. As the metals are generally embedded in polymer matrix in the PCB, the bioleaching efficacy of selected abundant metals, viz. Cu, Zn, and Ni from the PCB of discarded computer has been attempted in the study using Aspergillus tubingensis, a polymer-degrading fungal species. The bioleaching experiments were performed using the pulverized PCB with a particle size ranging from 0.038 to 1 mm at e-waste pulp density varying from 2.5 to 10 g/L for duration of 33 days. Results from the study revealed that the bioleaching efficacy of selected metals was decreased with the increase in e-waste pulp density. However, the bioleaching efficiency of Zn was found to be the maximum among the selected metals considered in the present study. Thus, the present study highlights the practical feasibility of bioleaching of metals from e-waste using A. tubingensis.