Green recovery of gold from waste mobile PCBs using deep eutectic solvent-based emulsion liquid membranes:...

Nowadays, the recovery of valuable metals from waste mobile phone printed circuit boards (WMPCBs) has attracted significant attention from researchers due to their economic potential. However, improper recycling poses serious risks to both human health and the environment. This study introduces, for the first time, a deep eutectic solvent (DES) as a novel, green, and highly selective carrier within an emulsion liquid membrane (ELM) system for the recovery of gold (Au) from WMPCBs. The proposed ELM system consists of petroleum ether as diluent, Span 80 as surfactant, and ascorbic acid as internal stripping agent, with DES serving as a sustainable alternative to conventional hazardous carriers. The tunable nature of DESs, achieved by varying the hydrogen bond acceptor (HBA) and hydrogen bond donor (HBD), allows for the design of tailored solvents with enhanced selectivity and efficiency. Response Surface Methodology (RSM) was employed to optimize key operational parameters, including internal phase ratio, emulsification time, and treat ratio. Under the identified optimal conditions (internal phase ratio = 1, emulsification time = 14.4 min, treat ratio = 5.7), the extraction efficiency reached 99.9 %. This DES-ELM strategy not only demonstrates exceptional performance but also offers an environmentally friendly and cost-effective solution for sustainable resource recovery from E-waste, effectively addressing the economic and environmental challenges associated with traditional recycling methods.