Electrolytic Preparation Of Potassium Ferrate In Water Treatment Applied Research

In this paper, the preparing methods, physical characteristics and the application of ferrates (Ⅵ) in the fields of syntheses of organic compounds, treatment of waste water and the usage as anode material in alkaline batteries were summarized. A series of influence factors on the electrolysis process for preparing K₂FeO₄ were investigated and the removal effects of CPB and Mn(Ⅱ) were also discussed.K₂FeO₄, An important and well-known ferrate, can be used as selective oxidant, battery materials and water treatment agent. However, the application of K₂FeO₄ has been greatly hampered due to the low current yield of synthesis. Thus, in the second chapter, K₂FeO₄ was prepared by electrochemical method. Factors, such as anodic materials, current density, electrolysis time and additions, were discussed on the current yield. The results show that the optimal parameters for K₂FeO₄ preparation are as follows: anodic material is iron lattice, current density is 0.5 mA·cm-2, electrode square is 100 cm2. KIO4 is a favorable addition. When the mass dosage of KIO4 is 0.02%, electrolysis time is 1 h, the current yield was enhanced by 31.6% and the corresponding purity of the product was improved by 3.85 %. The results will be much helpful to the mass production of K₂FeO₄ using electrochemical method.In the third chapter, a technology was developped based on removal of cetylpyridinium bromide (CPB) by using K₂FeO₄. Influences of the factors, such as K₂FeO₄ dosage, pH and oxidizing time, were investigated on the treatment result. The optimal conditions are as follows: initial solution pH is over 5, oxidation time is 5 min and K₂FeO₄ dosage is 1.5 times of that of CPB. Then infrared spectrum of CPB treated before and after experiment, UV spectrum of the filtrates with different reaction time, the kinetic processes of K₂FeO₄ and CPB were studied. In the removal process of CPB, a series of intermediary products were produced and finally turned into small inorganic molecular substance. The reaction of K₂FeO₄ and CPB responds to two levels of dynamics rules.In the fourth chapter, another technology was developped based on removal of Mn(Ⅱ) by utilizing K₂FeO₄. The removal rates of Mn(Ⅱ) in the aquatic system under the conditions of different pH, oxidization time and K₂FeO₄ dosage were investigated. At the same time, the effects of removing Mn(Ⅱ) by Al₂(SO₄)₃, K₂FeO₄ and the mixture of them were compared. The results show that K₂FeO₄ has great functions of oxidation, flocculation and assist-flocculation. In addition, Comparing with Al₂(SO₄)₃, K₂FeO₄ can greatly improve the removal effect of Mn(Ⅱ), and the mixture of them can achieve the best result.