Research On Removal Of Managanese By Chlorine Dioxide Pre-oxidation And Oxidation By-product Removal Of Chlorite

As a new type of water treatment chemicals,because of its safe and efficient oxidation characteristic,chlorine dioxide become more and more important in treatment of drinking water.Pre-oxidation for removing manganese is one of its important uses.In this dissertation,the technology of combining with conventional drinking water treatment processes and chlorine dioxide pre-oxidation to remove manganese and pre-oxidation by-products chlorite removal were studied.The main content of the study are as follows:(1)Firstly,study the influence of various factors on the removing manganese.Many factors were studied in the simulation.pre-oxidation of chlorine dioxide-coagulation.The dosage of chlorine dioxide and the acidity are very important for manganese removal,when the proportion of the dosage of chlorine dioxide to the original concentration of manganese is greater than 2.and the pH is between 7.5 and 8.5.the concentration of manganese will meet drinking water standards.The concentration of by-products ClO2- is close to the dosage of chlorine dioxide.The effect of temperature on removing manganese is slight.so the technology is suitable for hypothermia raw water.(2)Secondly. engage in the research of the effect of removing manganese by adding sodium hypochlorite and chlorine dioxide.Some conclusions were found in the simulation.The rate of removing manganese of sodium hypochlorite is much lower than the chlorine dioxide. If lmg/L Mn2+ is removed.29mg/L sodium hypochlorite is needed.when dosing sodium hypochlorite and chlorine dioxide together.these effect of removing manganese is independently of each other.(3)Finaly. study the method of removing by-product chlorite and its influencing factors.Some conclusions were found in the simulation,removing by-product chlorite.The actual amount of ferrous to remove chlorite is consistent with the theoretical value.Ferrous doseing slightly affect the rat of manganese removal,so this condition should be met:(The Concentration of Ma. in Raw water):(The Dosage of ClO2):(The Dosage of Ferrous)= 1:3:9.6.The technology of combining with chlorine dioxide and ferrous to remove manganese. not only ensure the efficient of removing manganese, but also solve the problem of excessive chlorite.,so is suitable for removing manganese in drinking water.