Studies On Stabilization Of Fe(Ⅵ) Compounds In Aqueous Solution

Fe(VI) compounds, which have increasingly gotten concerned by its advantages, have promising applications in areas of wastewater treatment, organic synthesis and electrochemical power. However, the bad stabilization in aqueous solution largely makes its applications limited. Therefore, it is important to stabilize Fe(VI) compounds.In the thesis, the stabilization of Fe(VI) compounds in aqueous solution, by monitoring the absorption, was studied. Firstly, in certain alkaline concentrations or distilled water with / without stabilizers including strong oxidants such as S₂O₈^2-,BrO₃^-, ClO₃^-, ClO₄^-, IO₃^-,etc., and compounds of Ca²⁺or Cl^-or else, the stabilization of Fe(VI) compounds was investigated focusing on effect of initial Fe(VI) compounds concentrations, alkaline solution, temperature, stabilizers , pH value on the stabilization. Then, the stabilization of Fe(VI) compounds was studied in buffer solution with different buffer compositions including phosphate, borate, and carbonate buffer solution. Furthermore, the mechanism and kinetics of stabilization was analyzed and discussed.The experimental results show that Na₂S₂O₈/K₂S₂O₈, Ca(ClO)₂ and KCl / NaCl are good stabilizers under certain environments, and the reaction is first order. The compounds such as CH3COONa, etc., accelerated the decomposition of Fe (VI) compounds. According to different stabilizer, the factors mentioned above worked differently. The stabilization of Fe(VI) compounds in phosphate, borate, and carbonate buffer solution was well. And other buffer solutions played a catalysis role on the stabilization of Fe (VI) compounds.