Study On Modified Activated Alumina By Polysilicate And Removing Fluorine Performance In Water

In this paper ,the best conditions of preparing modified activated alumina and the performance of fluoride removal were studied. When the percentage of SiO₂ is 2.30%,immersion in polysilicate 1.5h,roasting in muffle fuenace at 500℃and roasting 2h , In this conditon, we can get the best effect of fluoride removal by modified activited alumnian.The fluoride removal efficiency of unmodified and modified activited alumina was studied by the method of using batch reactor and continuous-flow column. In order to find the effects on fluoride removal, the way and condition of preparing modified activited alumina . It is compared the fluoride removal efficiency of activited alumina with modified activited alumina by batch reactor and continuous-flow column. The adsorption capacity and adsorption isotherm of fluoride removal are studied also .Batch reactor experiments show the adsorption capacity of activited alumina increases with the adsorption time longer and higher the concentration of raw water. The adsorption capacity is lower when pH increses,but the adsorption capacity is unconspicuous affect by pH. The adsorption isotherm of activited alumina conforms to Freundlich equation saturation adsorption capacity is compared unmodified activited alumina with activited alumina from 3mg/g to 6mg/g.The fluoride removal capacity is greatly improved.The continuous-flow column show the breakout curve is affected by the flow velocity, the raw concentration and the size of the alumina.It has been verified that the modified activated alumina is excellent for the removal of fluoride from drinking water to meet the dringking water quality standards.