Phosphate removal using free-standing functionalized mesoporous silica films with excellent recyclability

The fabrication of a novel adsorbent with biomass as template is a kind of effective and economical means to prevent the accelerated phenomenon of eutrophication. In this article, lanthanum(III)-coordinated amino-functional groups (La-EDA) anchored into free-standing mesoporous silica films to capture phosphate for the first time. The as-prepared modified free-standing inorganic/organic silica films (La-EDA-MSF) presented an outstanding adsorption property towards phosphate even at solution with high concentration of competing anions. The pH result manifested that the La-EDA-MSF could effectively capture phosphate over a wide pH range between 3 and 7. The reusability experiments indicated that no apparent adsorption capacity loss was observed compared with any other adsorbents. For the practical application, the phosphate absorption in environment sample by the as-prepared films was also evaluated and 98.35% of the phosphate could be removed by La-EDA-MSF in 1 h. In addition, the mechanism of phosphate absorption by this novel inorganic/organic silica film absorbent was also proposed. In general, findings in this paper could push forward the development of novel hybrid silica film adsorbent for application in rapid and efficient phosphate adsorption from the wastewater.