Study On Properties Of Potassium Ferrate And The Disposal Of Industrial Wastewater

Potassium ferrate is a new multi-functional water treatment agent with the novel properties of oxidation, adsorption, flocculation, coagulation, disinfection and deodorization. It has many prominent advantages such as a quick, no residual toxicity and does not cause secondary pollution of water bodies etc. In order to overcome its shortcomings,a series of investigation was carried on.In this paper the hypochlorite oxidation method was used for the synthesis of potassium ferrate. Through the study of many factors, optimum conditions had been identified:the reaction temperature was 25℃and the reaction time was 60 minutes; the increase in alkalinity and adding a small amount of sodium silicate could significantly increase yields.The EDTA method and chromate method used to test potassium ferrate concentration was compared and improved, and the improved EDTA method was used to test the concentration of potassium ferrate solution in the paper.The stability of potassium ferrate solution was studied. It was found that the stability of potassium ferrate increases with the increasing of the alkalinity concentration. Potassium iodate could reduce the stability, while sodium silicate could increase it.Potassium ferrate was used to degradate wastewater from the chemical plant .Under the initial conditions (pH=6.8), CODCr removing rate was the highest when the reaction time is 25 minutes;when the concentration of potassium ferrate was 30 mg·L-1, the removing rate of CODCr was 76 % and that of the turbidity and odor was about 80 %; while in acid conditions(pH=4.5) and 25 mg·L-1, the removing rate of CODCr is 95 % and that of the turbidity and odor was 98 %~99 %. Smell was also significantly reduced, too.