Research On Electrochemical Preparation Of Potassium Ferrate And It's Application In The Degradation Of Organophosphorus Pesticide

In this thesis, the electrolysis techniques for producing solid potassium ferrate (VI) and the degradation of organophosphorus pesticide by potassium ferrate were studied. An electrolysis cell was configured with two compartments separated by a membrane. The electrolyte was a concentrated solution of pure KOH. The anode was a material containing iron. A piece of nickel foam acted as the cathode. The solid K₂FeO₄ with the purity over 90wt% could be separated from the anolyte after electrolysis. The electrolyte could be successfully reused for further ferrate synthesis. No byproduct resulting pollution was produced in the process. The degrading effect of potassium ferrate in the aqueous solution of OPPs omethoate was studied under different condition by a determining method—gas chromatography, and find out the degradation of omethoate by K₂FeO₄ is very effective.The main results are shown as follow:1. The current efficiency increased obviously with rising electrolyte temperature. The effect of different solutes on the current efficiency of ferrate production varied apparently at different temperatures. For the solution of 16 M NaOH, the current efficiencyn increased and reached its maximum at 35℃, then decreased dramatically with increasing temperature, while the content of ferrate dropped remarkably and that of Fe(OH)₃ increased. However, the case was not that at all for the solution of 16 M KOH. The current efficiency was so low at 25℃ that no obvious solid K₂FeO₄ was observed. But it increased greatly with the increasing temperature higher than 35℃, while the molar ratio of Fe (VI) to total Fe in solid K₂FeO₄ decreased by only 2⁵% and always retained a value over 0.9.2. The higher the concentration of KOH was, the higher the current efficiency was. The effect of concentration of KOH was slightly on purity of solid K₂FeO₄ and the molar ratio of Fe(VI) to total Fe in it. The current efficiency reached its maximum when the apparent anodic current density was at 50⁷0 A/m².3. From the viewpoints of solid potassium ferrate yield, purity of solid of potassium ferrate, molar ratio of Fe(VI) to Fe(T) in solid K₂FeO₄, current...