Synthesis of novel composite sorbents based on titanium, calcium and magnesium phosphates

Abstract

Heterogonous and mechanochemical synthesis of new materials based on titanium, calcium and magnesium phosphates have been developed for the first time. Final products demonstrate high sorption efficiency towards heavy metal cations and radionuclides. The combined action of the components ensures high sorption capacity towards different cations within a wide pH range. The optimal conditions of the processes providing the obtaining of composite products with given phase composition have been established. Using solid precursors and phosphorus-containing agents taken in a stoichiometric ratio, and mild hydrothermal conditions make it possible to reduce liquid waste to a minimum level. During the first step of synthesis both precipitation of titanium phosphate and formation of ammonium phosphate which is the precursor for the second step occur. The latter is the formation of calcium and magnesium phosphates. Thus, the synthesis proceeds in accordance with the principles of green chemistry.