Fungal bioleaching of e-waste utilizing molasses as the carbon source in a bubble column bioreactor

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 printed circuit boards (MPPCBs) waste. Molasses was used as an efficient carbon source to enhance bioleaching efficiency and increase the cost benefits. The adap-tation phase was done at Erlenmeyer flasks to reach 40 g/L of MPPCBs powder. The most significant parameters, including the mass of MPPCBs powder, aeration, molasses concentration, and their interaction, were optimized in order to leach the maximum possible Cu and Ni using central composite design in response surface meth-odology (RSM). The model p-values for Cu and Ni recovery were 0.0030 and 0.0348, respectively, emphasizing the model's accuracy. 96.94% of Cu was recovered under 8.8% (v/v) of molasses, aeration rate of 0.29 (l/min), and MPPCBs powder 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 MPPCBs powder of 10 g/L, resulting in 71.51% recovery. The present article demonstrated the great potential of P. simplicissimum to improve metal recovery from e-waste utilizing molasses and bubble column bioreactors.

Automated summary

This study utilized Penicillium simplicissimum in a bubble column bioreactor to extract copper and nickel from discarded mobile phone printed circuit boards (MPPCBs). The use of molasses as a carbon source improved bioleaching efficiency and cost benefits. Optimization of parameters resulted in high recovery rates of Cu and Ni, demonstrating the potential of P. simplicissimum in metal recovery from e-waste.