Controlling The Acidic Sorption Sites Of Layered Double Hydraoxides And Its Effect Of Adsorption Chloride Ion

Chloride ion widely exists in the natural world. It is severe harmful for the environment if there are too much chloride ion in the water or earth. And also, chloride ion is a severe problem in producing the PVC and synthesis of polymer materials. So, studying the adsorption of chloride ion and the adsorption mechanism is necessary and useful.Layered double hydroxides are classic anionic clays. It composes of positive charged layers and interlayers anions. The positive charged layers have the property of basicity. And the basicity of LDHs could neutralize the H", and the Cl- could be adsorped into the interlayer by ion exchange.In this paper, we change the synthesis conditions to control the acidic sorption sites, testing the adsorption capacity of chloride ion and studying the adsorption mechanism. In our study, the result indicates that prolonging the crystalization time could increase the amount of acidic sorption sites and the adsoption capacity, and it has the same result when reducing the concentration of metal ion.The result of NH3-TPD incidcates that the adsorption ability is better if the acidic sorption sites become more. Prolonging the crystalization time and decrease the concentration of metal ion contributes to increase the acidic sorption sites.In this paper, we mixed different volume ethanol with the solution of metal aion and urea. The result of NH3-TPD incidcates that increaseing the volume of ethanol could change the amount of acidic sorption sites, and then the adsoption capacity changes heavily, The adsorption capacity increase slightly when joined little volume ethanol and the adsorption capacity increase sharply when the ethanol volume gets 60 ml or 80 ml. The result of adsorption capacity is accordance with the the amount of acidic sorption sites.