Adsorption behavior of phosphate on Lanthanum(Ⅲ) doped mesoporous silicates material

摘要

A series of lanthanum doped meosoporous MCM-41(LaxM41,x is Si/La molar ratio) was prepared by sol-gel method.The surface structure of the materials was investigated with X-ray diffraction and N2 adsorption/desorption technique.The content of La in the materials was determined by ICP.It was found that the La content of La25M41,La50M41 and La100M41 was 7.53%,3.89% and 2.32%,respectively.The phosphate adsorption capacities increased with increasing amount of La incorporation.With 0.40 g La25M41 99.7% phosphate could be removed.The effects of Si/La molar ratio,LaxM41 dose,pH,initial concentration of phosphate solution,co-ions on phosphate adsorption were also evaluated.The phosphate adsorption kinetics of LaxM41 could be well-described by the pseudo second-order model,and Langmuir isotherm fit equilibrium data much better than the Freundlich isotherm.