| The fluorine is one of the most important micronutrient for both humans and animals, it plays an important role in the maintenance healthybones and teeth. However, excess intake of fluoride could lead to fluorosis. Todate, various technologies of removal F- from water are applied widely around the word. For example, adsorption removal, coagulation-preci- pitation, ion-exchange, membrane separation process, electrodialysis, electro-coagulation etc., in which adsorption and coagulation-precipitation are the most wildly used methods in drinking water treatment.Magnesia has been proved to be an adsorbent showing extremely high defluoridation capacity(DC). In order to obtain an adsorbent which has higher DC, the present work prepared a composite(MgOS) from magnesia and soluble starch. To achieve maximium fluoride removal efficiency, a series of experiments were conducted. Result showed that the optimal ratio of MgO to soluble starch is determined as 1:1, and the optimal calcine time and the optimal calcine temperature were measured as 4h and 400℃, meanwhile, the result of batch equilibrium defluoridation experiments with MgO and MgOS composite showed that get a high defluoridation capacity of 2256 mg F?/kg in 50 minutes; When the pH changed from 2 to 12 , MgOS composite remained high adsorption capacity relatively.SEM, XRD and FTIR were performed to characterize the physicochemical properties of the synthesized MgOS composite. Furthermore, analysis of thermal and kinetic model indicated that the equilibrium data fit very well with Langmuir isotherm model, pseudo-second-order models, respectively. whilst,ΔG0,ΔH0 andΔS0 showed that the spontaneous and endothermic in nature was involved in ?uoride removal process.MgOS composite has a better environmental adaptability and high defluoridation capacity, therefore, it is a good defluoridation materials with great prospect. |
PDF Full Text Request