The Sorption Study Of Potassium Zinc Hexacyanoferrate??? Compound On Co²⁺ And Cu²⁺ In Simulated Radioactive Wastewater

The rapid development of nuclear science and technology has improved people's life greatly. At the same time, large amounts of radioactive wastewater will be generated by the activities in nuclear power plant and hospitals. The radioactive wastewater may seriously affect people's health and living environment. Therefore, it is very urgent to study the theories, technologies and methods which can solve the problems of radioactive wastewater effectively.In this paper, we prepared potassium zinc hexacyanoferrate(II)(KZn FC), potassium zinc hexacyanoferrate(II)/magnetite composite(KZn FC/Fe3O4) and potassium zinc hexacyanoferrate(II)/silica composite(KZn FC/Si O2) by coprecipitation and in situ precipitation. The materials were characterized by TEM, ICP, XRD, and M?ssbauer and were used as adsorbents for removal of cobalt and copper from simulated radioactive wastewater. The effect of temperature, p H, contact time and initial ion concentration on sorption behaviors in simulated radioactive wastewater was studied by static sorption method. Typical sorption isotherms and sorption kinetics were used for sorption fitting. Besides, TEM, ICP, XRD, and M?ssbauer were analyzed for studying the sorption mechanism of KZn FC on Co2+ and Cu2+.In this paper, we have successfully synthetized materials of KZn FC, KZn FC/Fe3O4 composite and KZn FC/Si O2 composite. The results show that the sorption equilibrium time of these materials on Co2+ and Cu2+ in simulated radioactive wastewater was 3h, 1h, 1h, respectively. The sorption was influenced by p H greatly, and it was found to fit with pseudo-second-order type sorption kinetics for all materials. The sorption of KZn FC on Co2+ was endothermic reaction, and the sorption isotherm was more consistent with the Langmuir sorption model. The sorption of KZn FC on Cu2+ wasn't affected by temperature. And its sorption isotherm was consistent with the Freundlich sorption model better. The sorption of KZn FC/Fe3O4 composite on Co2+ and Cu2+ would not affected by temperature, while the sorption of KZn FC/Si O2 composite were endothermic reaction. The sorption isotherm of KZn FC/Si O2 composite on Co2+ and Cu2+ were consistent with the Freundlich sorption model. In the same conditions, the saturate sorption capacity of KZn FC on Co2+ and Cu2+ were 38.53 mg/g and 45.03mg/g, KZn FC/Fe3O4 composite were 43.87 mg/g and 48mg/g, and KZn FC/Si O2 composite were 42.14 mg/g and 47.05mg/g. In the study of the sorption mechanism of KZn FC, we found that sorption of KZn FC on Co2+ is the ion exchange between K+ and Co2+, while on Cu2+ among K+, Zn2+ and Co2+.The study has significant guiding function for preparating high selective and great sorption capable materials for treatment of radioactive wastewater. In addition, it is also has significant meaning for exploring the effective treatment method.