Copper recovery from printed circuit boards leaching solution with bioelectricity generation using microbial fuel...

Recovery of valuable metals via leaching printed circuit boards (PCBs) has gained moment recently. This work studied the Microbial fuel cell (MFC) performances for recovery of Cu from a Cu²⁺ solution by examining key operating parameters. A dual-chamber MFC with 6 cm × 6 cm × 7 cm dimensions was constructed. Both anode and cathode electrodes were made of a carbon cloth sheet. The anodic and cathodic chambers were separated by a Nafion membrane. The highest Cu recovery efficiency was 99.7% after 240 h batch mode operation, yielding 102 mW/m² MFC power density output using 1 g/L Cu²⁺ solution as the catholyte (initial pH 3) and an anolyte containing 1 g/L sodium acetate inoculated with a sludge from a wastewater treatment plant's anaerobic pond, with 2 cm distance between the electrodes made of polyacrylonitrile polymer. The highest open circuit voltage, current density (based on cross-section cathode area) and power density with an external load of 1 kΩ was 555 mV, 347 mA/m² and 193 mW/m², respectively. Additionally, recovery of Cu in the leachate of PCBs using sulfuric acid leaching after 48 h was performed and the highest Cu recovery was 50% in 48 h.