09:45 〜 10:00
[AGE29-04] Sorption characteristics of the improved coal mine drainage treated sludge (CMDS) for cesium (Cs) in an aqueous solution
キーワード：cesium, coal mine drainage treated sludge, eco-friendly material, radioactive nuclide, sorption
By considering the hazards of radioactive cesium-137 (Cs), the Cs removal from aqueous solutions has garnered widespread concern, emphasizing the necessity for developing practical new Cs sorbents. Most of the previously studied Cs sorbents have high costs and limitations in treating large-scale water solutions with low Cs concentration and high ionic strength. Furthermore, powder-type sorbents are impractical for treating contaminated water in an actual aquatic environment, as there is no easy way to separate the powder-type sorbents after they are used in the treatment process.
In this study, a novel eco-friendly Cs sorbent, named "Na-S-CMDS”, was developed by adding sodium (Na) and sulfur (S) to the coal mine drainage treated sludge (CMDS), generated during the treatment of drainage from the abandoned coal mines. To evaluate the Cs sorption capacity and to understand the Cs sorption mechanisms of the Na-S-CMDS, sorption batch experiments were performed under various pollution environmental conditions. From the results of sorption batch experiments, the Cs-133 sorption of the Na-S-CMDS reached the equilibrium within a short reaction time (< 1 hour), and the Na-S-CMDS showed the high Cs removal efficiency (> 90.0%) even at the low Cs concentration condition (< 0.5 mg/L). The Na-S-CMDS maintained the high Cs removal efficiency (> 80.0%) over a wide range of pH (pH 2 to 11). From the visual analysis and the sorption model study, the primary Cs sorption mechanisms of the Na-S-CMDS were the active ion exchange between Na+ and Cs+ at first, and the strong binding affinity of sulfur and Cs+ based on the ‘hard soft acid base (HSAB) theory’ as the second.
The granulation process of powdered Na-S-CMDS was carried out using the biopolymer to facilitate the separation of the sorbent from an aqueous solution. The Na-alginate was selected as the biopolymer material, and batch experiments were performed to assess whether the alginate-granulated Na-S-CMDS exhibits the high Cs removal efficiency under identical conditions. Results of this study demonstrated that the granular type of the Na-S-CMDS, manufactured by using the eco-friendly binder (Na-alginate), had remarkable potential for the cost-effective Cs removal from radioactively contaminated water systems.
*This research was supported by Particulate Matter Management Specialized Graduate Program through the Korea Environmental Industry & Technology Institute (KEITI) funded by the Ministry of Environment (MOE).
In this study, a novel eco-friendly Cs sorbent, named "Na-S-CMDS”, was developed by adding sodium (Na) and sulfur (S) to the coal mine drainage treated sludge (CMDS), generated during the treatment of drainage from the abandoned coal mines. To evaluate the Cs sorption capacity and to understand the Cs sorption mechanisms of the Na-S-CMDS, sorption batch experiments were performed under various pollution environmental conditions. From the results of sorption batch experiments, the Cs-133 sorption of the Na-S-CMDS reached the equilibrium within a short reaction time (< 1 hour), and the Na-S-CMDS showed the high Cs removal efficiency (> 90.0%) even at the low Cs concentration condition (< 0.5 mg/L). The Na-S-CMDS maintained the high Cs removal efficiency (> 80.0%) over a wide range of pH (pH 2 to 11). From the visual analysis and the sorption model study, the primary Cs sorption mechanisms of the Na-S-CMDS were the active ion exchange between Na+ and Cs+ at first, and the strong binding affinity of sulfur and Cs+ based on the ‘hard soft acid base (HSAB) theory’ as the second.
The granulation process of powdered Na-S-CMDS was carried out using the biopolymer to facilitate the separation of the sorbent from an aqueous solution. The Na-alginate was selected as the biopolymer material, and batch experiments were performed to assess whether the alginate-granulated Na-S-CMDS exhibits the high Cs removal efficiency under identical conditions. Results of this study demonstrated that the granular type of the Na-S-CMDS, manufactured by using the eco-friendly binder (Na-alginate), had remarkable potential for the cost-effective Cs removal from radioactively contaminated water systems.
*This research was supported by Particulate Matter Management Specialized Graduate Program through the Korea Environmental Industry & Technology Institute (KEITI) funded by the Ministry of Environment (MOE).