Facile synthesis of magnetic La-Zr composite as high effective adsorbent for fluoride removal

A novel magnetic composite of La-Zr was prepared by co-precipitation method, and its fluoride removal ability was investigated in batch studies. The sample was characterized by SEM, EDS and FTIR. Influence of various factors such as pH, presence of coexisting anions, contacting time and initial fluoride concentration were studied in detail by batch sorption experiments. The equilibrium data fitted to Langmuir, Freundlich and Lan-Fre isotherm model, and the maximum sorption capacity was calculated to be 88.5 mg g(-1), which is higher than lots of previous adsorbents. The kinetic data can be described well by the pseudo-second-order kinetic model. It was indicated that the overall rate of fluoride sorption is likely to be controlled by chemisorption process. Based on the results, the mechanism of adsorption was discussed in detail. There is no calcination in the preparing process, so this material is considered to be lower cost as compared with some metal elements-based oxides adsorbents, and is beneficial for the practical application.