Carbon fibres as electrodes for the recovery of nickel from industrial wastewater†

This study presents an innovative approach to the recovery of nickel from industrial wastewater using cost-effective carbon fiber electrodes, aiming to provide a sustainable and scalable solution for industrial effluent management. Carbon fibers offer unique benefits in electrochemical recovery processes due to their high surface area, excellent conductivity, mechanical durability, and compatibility with low-cost production. The optimized conditions, including a deposition potential of 4 V, pH 3.5, and temperature of 60 °C, achieved a high nickel recovery efficiency of 90%, with minimal energy consumption at 3 kW h per kilogram of nickel. This efficiency was verified through Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray (EDX) analyses, which revealed uniform and dense nickel coatings on the carbon fibers, even under continuous operation. Fourier Transform Infrared Spectroscopy (FTIR) and X-ray diffraction (XRD) confirmed successful nickel deposition and modifications to the carbon fiber surface chemistry, enhancing the adsorption and reduction of nickel ions. Using carbon fiber electrodes in this process addresses several limitations in traditional electrode materials by reducing costs, improving scalability, and supporting continuous, large-scale nickel recovery. This method offers a viable alternative to conventional electrochemical metal recovery and contributes to circular resource utilization by recycling valuable metals from wastewater. With regulatory pressures increasing around heavy metal discharge limits, this carbon fiber-based electrodeposition process presents a highly promising solution for industrial wastewater treatment, combining environmental sustainability with economic feasibility.