Sorochkina K. Obtaining of sorbents based on zirconium(IV) and aluminum(III) oxyhydroxides by sol-gel method.

The thesis is devoted to the determination of sol-gel process regularities for receiving of sorbents based on zirconium(IV) and aluminum(III) oxyhydroxides and the development of sorbents technology based on them. The process of zirconium(IV) and aluminum(ІІІ) hydroxides formation in aqueous solutions of their salts theoretically and experimentally was investigated. It was found, that the stage of hydrolysis process during sols formation of zirconium(IV) and aluminum(ІІІ) oxyhydroxides does not depend on the molar ratio of Zr(IV) to Al(III) ions, and is limited by hydrolysis of carbamide, the rate constant at Т=373 К equals k=0.00303 min-1. The size of primary particles does not exceed 15 nm, the diameter of particles at the moment of gel formation is equal to 32-47 nm. The granulation process of obtained sols was studied. The conditions to obtain of spherical granules of sorbents by using of organic matter layer and without it was determined. The influence of the composition and process conditions to obtain of sorbents based on zirconium(IV) oxyhydroxide on their physico-chemical and sorption properties was studied. The sorption process of Mn2 + and As(III) and As(V) ions by sorbents was studied experimentally. Based on the research, technological parameters was established and the process flow diagram to produce of sorbents based on zirconium(IV) and aluminum(ІІІ) oxyhydroxides was developed.