Exploration On Regeneration Mechanism And Phosphate Removal Of La-Fe Composite Oxide

With the increasingly serious eutrophication, the methods of phosphate removal became more important. Adsorption method has high phosphate adsorption effect, and can be regenerated. This paper based on the preliminary research results, Preparation the Fe-doped La-Fe composite oxide, the phosphate removing agent was researched by the absorption characteristics. Contrast the two different phosphate removing agents, lanthanum oxide and activated carbon, and study on its adsorption properties. In the study, the phosphate removing agent can be regenerated many times, and study of it’s regenerative efficiency.The best La-Fe composite oxide was obtained when the calcination temperature on400℃, the adsorption capacity data is99.92mg/g after roasting. Drying conditions has great influence on the adsorption properties of La-Fe composite oxide. The ability of phosphate absorption in lanthanum oxide was higher than that in lanthanum hydroxide.Through investigation and comparison of the adsorption capacity data of La-Fe composite oxide、lanthanum oxide and activated carbon, among them, the adsorption capacity data of La-Fe composite oxide is highest, followed by lanthanum oxide, and finally activated carbon. Chemisorptions play a major role in the process of the phosphate removing agent absorbs phosphate.In the study, the three different phosphate removing agent can be regenerated many times under vacuum conditions, after primary recycling, the regeneration efficiency of La-Fe composite oxide、lanthanum oxide and activated carbon was in sequence of58.4%、58.89%and22.38%, after three times recycling, he regeneration efficiency of La-Fe composite oxide、lanthanum oxide and activated carbon was in sequence of43.2%、44.9%and6.7%. After regenerated many times, the adsorption of phosphate removing agent reduced, but the regeneration efficiency change is to gradually slow.After regenerated many times, their surface area and pore size of phosphate removing agent were reduced, the adsorption capacity of the phosphate removing agent maybe have relation to the pore structure. but the surface area and pore size are not the key factor in adsorption, they played minor effect.