Heavy metals in the environment. Part I: Removal of cobalt from dilute effluent streams by fluidised bed electrolysis

Abstract

AbstractThe fluidised bed cell is an electrolytic reactor which is designed to provide higher ion‐transfer conditions during electrolysis by breaking up the barrier layer at the cathode, thus enabling metals to be removed efficiently from dilute solutions. The effectiveness of the method as a means of removing metals from effluent to meet discharge consent levels is studied for the in‐situ removal of cobalt from dilute solution. The effects of cathode density, pH, reaction time, buffer solution composition, buffer concentration and agitation on the removal of cobalt are reported and expressed in terms of the percentage removal of cobalt (αCo), the efficiency for cobalt deposition (∞Co), and the energy consumption (WCo) for 1 kg of cobalt deposited. The results show that cobalt can, under optimised conditions, be removed from dilute solutions to a residual level of 0.2 ppm.