이온교환섬유를 이용한 수중 비소(Ⅴ) 제거에 관한 연구

Abstract

Recently, The arsenic concentrations found in natural waters ranges from less than 0.5 mg/L to more than 5000 mg/L. Due to the high toxicity of arsenic, the United States Environmental Protection Agency (US EPA) and World Health Organization (WHO) recommend a maximum contaminant level of 10 ㎍/L for arsenic in drinking water. In order to solve this problem, physical and chemical arsenic removal technologies investigated. To select the most appropriate treatment technology, the disposal option for residuals and costs should be considered along with the treated water quality. The ion exchange process does not generate a large amount of waste and the resins can be regenerated. Thus, this study focuses on ion exchange fibers and their application for the removal of As(Ⅴ) from aqueous solution in batch system. As(Ⅴ) removal experiments were performed to examine the effects of solution pH, input quantity, initial arsenic concentration, and regeneration effects. The As(Ⅴ) removal efficiency of the ion exchange fiber was affected by the solution pH and the efficiency was affected according to the fiber's functional group. The removal efficiency of As(Ⅴ) was increased by increasing the input quantity of ion exchange fibers. The removal efficiency of As(Ⅴ) increased as the initial concentration of the As(Ⅴ) solution decreased. The ion exchange fibers can be effectively regenerated by using 0.5 M NaCl and the regeneration efficiency changed according to the fiber's functional group. Adsorption equilibrium data for As(Ⅴ) on the ion exchange fibers reasonably matched the Langmuir isotherm model. In addition, bath adsorption studies have shown that the adsorption reaction can be described by the secondary-order reversible reaction. The adsorption energies obtained from the D-R model for the KC31, SA and SA2 ion exchange fibers, 18.35, 10.25 and 9.25 kJ/mole, respectively. This indicates that chemical sorption is the main adsorption mechanism for the KC31 ion exchange fiber and that ion exchange is the main adsorption mechanism for the other ion exchange fibers. In the continuous experiments, the KC31 ion exchange fiber treated 800mL of the As(Ⅴ) solution at 8.67 mL/min, and 3,020 mL of the As(Ⅴ) solution at 8.67 mL/min. The KC31 ion exchange fiber was regenerated using a sodium chloride (0.5 M NaCl) solution.