Effects of Extracellular Polymeric Substances and Specific Compositions on Enhancement of Copper Bioleaching Efficiency from Waste Printed Circuit Boards

Abstract

Bioleaching has been proven to be an efficient and environment-friendly method for processing metalliferous ore and waste printed circuit boards (PCBs), a type of urban mine waste. Extracellular polymeric substances (EPS) play a major role in the attachment of bacteria to the surface of sulfide minerals. However, there are few reports on the effects of EPS components on the bioleaching of metals from PCBs. In this study, synthetic EPS were used to investigate the effects of the composition of exo-polymers on the bioleaching of copper from waste PCBs, including the process efficiency. The copper extraction rate in bioleaching assays with synthetic EPS was 11.7% greater than in those without synthetic EPS. Moreover, the composition of EPS was proven to be a crucial factor affecting the efficiency of copper bioleaching, with EPS containing arginine yielding the highest recovery (95.2% copper). Under the condition of 0.5 g/L synthetic EPS added at the early stage of log phase, the copper leaching efficiency from waste PCBs was highly improved. This study provides important insights into how to analyze the working mechanisms of EPS for a better recovery efficiency.

Application of Acid Mine Drainage for the Biooxidation of a High-Grade Refractory Sulfide Gold Ore

“…They concluded that AMD improved the bioleaching of bornite, and in general, the use of this solution for the bioleaching of low-grade sul de ores had a positive result. Xu, Zhu [9] applied Acidithiobacilus ferrooxidans existed in an AMD sample to the bioleaching of copper from waste printed circuit boards and achieved a high dissolution e ciency.…”

Characterization and Sustainability Potential of Recycling 3D-Printed Nylon Composite Wastes

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