Electrolytic Recovery of Nickel from Spe

Plating industry is one of the largest polluting small scale industries, with nickel plating being a significant surface finishing process that generates toxic waste. This study aims to investigate the electrolytic recovery of nickel from spent electroless nickel bath solutions, particularly from a relay switch manufacturing industry in Chennai. The methodology involved conducting electrolytic experiments using mild steel and gold-coated mild steel as cathodes, with variation in parameters such as current density, time, mixing, and pH of the solution. Results indicated an increase in current efficiency up to 5 A/dm², after which efficiency began to decline, with mixing showing no significant improvement. However, a modified cathode demonstrated some enhancement. At optimal conditions of 5 A/dm² and pH 4.23, nickel removal reached 81.81%, reducing nickel concentration from 5.16 g/L to 0.94 g/L, while achieving a current efficiency of 62.97%. These findings underscore the potential for effective nickel recovery from industrial waste, contributing to both environmental sustainability and resource recovery.