In-situ synthesis process of birnessite to remove Co2+ from the simulated radioactive wastewater

Abstract

In this study, the in-situ synthesis of birnessite successfully removed Co²⁺ from simulated radioactive wastewater. The optimal reaction conditions were determined by single-factor experiments: a reaction time of 60 min, a pH of 11, a reaction temperature of 50°C and a Mn²⁺/Co²⁺ molar ratio of 7:1. The removal rate of Co²⁺ reached 99.97%. XRD confirmed birnessite as the precipitate. FTIR, precipitate dissolution and XPS analyses indicated that the removal mechanisms of Co²⁺ included hydroxide precipitation (0.36%), adsorption (4.70%) and ion exchange (94.94%). In conclusion, the in-situ synthesis of birnessite for Co²⁺ removal is promising for the treatment of radioactive wastewater.