Removal of metal ions from electrochemical decontamination solution using organic acids

Abstract

Applicability of the organic acids and cyclodextrin (CD) for the removal of Fe, Co and Ni from the spent electro-decontamination solution was investigated. Oxalic acid showed the highest removal efficiency: 90% for 0.89M Fe and 95% for 0.0089M Co and Ni, respectively. The metal-oxalate precipitates were characterized by differential scanning calorimetry/thermogravimetry analysis (DSC/TGA), Fourier transform infrared (FTIR) and X-ray fluorescence (XRF). After thermal decomposition at >300 degrees C, the metal-oxalate precipitates were transformed into metal oxides (Fe2O3, FeO, CoO and NiO) and pure metals (Co and Ni). The results imply that organic acids have a high potential for the removal of heavy metals from electro-decontamination solutions.