Multi-objective optimization of bioleaching from e-waste in a bubble column bioreactor by Penicillium simplicissimum utilizing molasses as the carbon source

Mobile phones are known as the most widely used electronic instruments, and an enormous number of discarded mobile phones are generated. The present work used a pure culture of Penicillium simplicissimum in a bubble column bioreactor to extract Cu and Ni from mobile phone PCBs (MPPCBs) waste. Molasses was used as an efficient carbon source to enhance bioleaching efficiency and increase the cost benefits. The adaptation phase was done at Erlenmeyer flasks to reach 40 g/l of pulp density. The most significant parameters, including pulp density, aeration, molasses concentration, and their interaction, were optimized to leach maximum possible Cu and Ni using central composite design in response surface methodology. 96.94% of Cu was recovered under 8.8% (v/v) of molasses, aeration rate of 0.29 (l/min), and pulp density of 10 g/l. The optimized condition of Ni leaching was 1.9% (v/v) of molasses, aeration rate of 0.37 (l/min), and pulp density of 10 g/l leading to 71.51% recovery.