Influence of coexisting EDTA, citrate, and chloride ions on the recovery of copper and cobalt from simulated wastewater using fluidized-bed homogeneous granulation process

Copper and cobalt from industrial operations build up in the environment, posing a substantial health risk. This study examined how ethylenediaminetetraacetic acid (EDTA), citrate, and chloride ions affected the fluidized bed homogeneous granulation process' (FBHGP) ability to recover both individual and combination of copper and cobalt ions from simulated waste streams. A 99% copper removal and 95% granulation efficiency were attained in copper-based solutions. The soluble copper still present in the solution caused a 4% variation in the removal and granulation efficiencies. There were 99% removal and 99% granulation efficiencies in cobalt-based solutions. When EDTA was present in a copper-based solution, 95% removal and 86% granulation were reached, and for cobalt-based solutions, 95% and 91% were the removal and granulation efficiency, respectively. The presence of citrate in the copper-based solution obtained the removal of 83% and granulation efficiency of 54% at 0.1 MR of citrate to copper. No copper phosphate precipitate was formed when the MR was greater than 0.1. There were 96% removal and 92% granulation efficiency when citrate was present in cobalt-based solutions. The presence of chloride ions in copper solution achieved a 99% removal and 91% granulation efficiency, while in cobalt solutions, 99% removal and 98% granulation efficiency were attained. Solutions with combined copper and cobalt with chloride ions achieved 99% removal and 95% granulation efficiency for copper and 99% removal and 95% granulation efficiency for cobalt. The granule sizes decreased as the MR of the complexing agents to metal, and the concentration of chloride ions increased. The peaks on the XRD pattern exactly matched the peaks of cobalt phosphate hydrate (Co3(PO4)2·8 H2O). FBHGP has effectively recovered copper and cobalt from the waste streams of simulated metals.