The Preparation,Characterization Of Polyiodides And Its Application In Water Disinfection

Water is a necessary condition for the existing of human being,but also is one of the important transmission media of numerous kinds of diseases,so water disinfection has become a significant measure to ensure the security of public health.Polyiodides are recognized as new kind of safe and efficient disinfectant.The resin polyiodides has been widely applied to water dispenser disinfection,but there is a problem that the residual iodine is significantly overweight.Furthermore,it can not be directly used in the tap water disinfection so far because of the poor solubility of polyiodides,which all limit the widely applications of polyiodides.Aiming at the overproof of residual iodine,this paper firstly developed the resin polyiodides with stably iodine release,and then used it as a releasing agent of iodine and bactericide,cooperating with the activated carbon fiber material,adsorbent resins,and granular activated carbon to develop the resin polyiodides straight water dispensers.For the problem of poor solubility of polyiodides,by choosing a safe,easily degradable,water soluble ligand and coordinating the polyiodides to the ligand to make an easily solute in water,safe in use,durable disinfection and easily degraded and could be directly applied to water disinfection.?1?The preparation of stable release resin polyiodides and its application in direct water dispensersPolyiodides was obtained through iodine and potassium iodide polymerized in different mole ratio,and then reacted with resin by using the aggregation-ion exchange method.By controlling the resin exchange rate,ratio of raw material and adding different stabilizer,different iodine content and degrees of polymerization of resin polyiodides was prepared and the structure and properties of the polyiodides was characterized and measured.The prepared resin polyiodides were used as the disinfectant and releasing agent of iodine and using the adjustment of adsorbent resin,and then combine three composite filter series,eventually the structure of resin polyiodices direct water dispensers was improved,achieving the function of disinfection,water purification and adjusting iodine.The results indicated that the stable iodine releasing of resin polyiodides can be prepared by controlling the resin exchange rate,mole ratio of raw materials and different stabilizers.The iodine content of which was between 6.25?61%,and the degree of polymerization was between 2.83?6.76.Polyiodide ion in resin polyiodides was made up by I₃^-and I₅^-,and its sterilization mechanism is the dissolved I₂ in the water.The resin polyiodides direct water dispensers showed excellent comprehensive performance of disinfection,the terminal total iodine content can be controlled within the scope benefiting to human health,meeting the demand of low iodine regions to fill iodine and high iodine areas to reduce the iodine.?2?The preparation of the water-soluble polyiodides and its application in disinfection of tap waterUsing the coordination-precipitation method,the water soluble starch and polydextrose were used as the ligand of the polyiodides,by controlling the ratio of raw material and adding stabilizers,the starch polyiodides and polydextrose polyiodides with different iodine content and degrees of polymerization were prepared for the first time;the iodine content and degrees of polymerization for the water-soluble polyiodides were analyzed and measured by chemical titration;The polyiodides molecular structure of the material were analyzed and measured by Roman spectrum;The influence regularities of reaction temperature and reaction time on the iodine content and degrees of polymerization polyiodides were investigated.The thermostability of the material was analyzed and measured by TG/DTG/DSC;the water solubility and the storage stability were measured,finally the water-soluble polyiodides were applied to the tap water disinfection and the disinfection effect with different concentration was measured.The research results indicated the starch polyiodides and the polydextrose polyiodides can be obtained using the method of coordination–precipitation.The existence form of the polyiodide ions in water-soluble polyiodides with different degree of polymerization were the same,which were all the mixture of I₃^-and I₅^-;These two kinds of solid polyiodides has good stability,and the prediction of storage life can be more than two years.The water-soluble polyiodides belonged to dissolving level polyiodides;its bactericidal action was mainly depended on the I₂ dissolved in water.The results of the suspension quantitative disinfect experiment indicated that 6mg/L of polyiodides effected on bacillus coli 15min,the sterilizing rate reached over 96%.Finally,the two polyiodides both could meet the requirements of safe and effective in disinfection of tap water.This paper not only solved the problem of residual iodine excess of straight water dispensers and the poor water solubility of polyiodides,but also provided a new way for the safe and efficient water disinfection.