Optimization Techniques of Heavy Metal Recovery from Printed Circuit Board Industrial Wastewater for Sustainable Waste Resource Management

Abstract

The rapid expansion of the electronics industry, massive amounts of wastewater containing hazardous heavy metals including copper (Cu), lead (Pb), nickel (Ni), tin (Sn), silver (Ag) and gold (Au) are generated, particularly from the production of printed circuit boards (PCBs). Traditional approaches such as chemical precipitation, ion exchange, membrane filtration and electrochemical processes are widely applied but are generally costly, generate a large amount of sludge and lack the potential for metal reuse. This research assesses and optimizes various technologies for removing heavy metals, including the use of oxalate precipitation as a recovery process. Operating parameters including pH, temperature, oxalate-to-metal molar ratio, time, and metal concentration were investigated using an artificial intelligence supported model to determine the optimal conditions. The findings suggest that oxalate precipitation is an effective treatment approach for metals like Cu and Pb with high removal efficiencies and reduced sludge generation compared to traditional precipitation. Moreover, the metal oxalates can be converted into valuable metal oxides, allowing resource recovery and reuse in manufacturing. In summary, the research demonstrates the feasibility of using oxalate-based treatment as an eco-friendly and resource-saving approach to PCB wastewater treatment.