адсорбція

The kinetics of adsorption of ammonium ions under dynamic conditions has been studied. A mathematical model of the process was built. The mass transfer coefficient was calculated depending on the intensity of the change of location. It was established that ion exchange occurs in external and internal diffusion regions. The rate constants of ion exchange for the region of external and internal diffusion were calculated.

A detailed analysis of literature sources on the content of fluorides in the environment, methods of conditioning and defluoridation of water was held. The mechanism of interaction of fluorides with zeolite in the process of adsorption treatment of wastewaters and domestic waters was clarified. It was first established that in the process of adsorption there is the formation of magnesium fluoride compounds due to the binding of cations extracted from the zeolite by the mechanism of ion exchange.

Adsorption of nickel and chromium was investigated using fuller’s earth. The experimental data were analyzed using five 2-parameter adsorption models and three 3-parameter models. The maximum adsorption capacities for nickel and chromium were 769 and 556 mg/g, respectively. The Langmuir isotherm model was found to have the best fitting indicating monolayer adsorption. The adsorption was found to have an exothermic nature.

This work reveals a method of complex thermal and chemical activation of natural clinoptilolite from Sokyrnytsky deposit. The chemical activation of a mineral was carried out by HCl solutions treatment at various ratios of liquid-to-solid phases. With the use of thermal and infrared (IR) spectroscopic analyses, the adsorption property of a natural and activated clinoptilolite has been examined for water vapor. The ability of complexly activated clinoptilolite to adsorb direct dyes from their aqua solutions has been investigated.

The IR spectroscopy and complex thermal analysis have been used to analyze the adsorption capacity of Transcarpathian clinoptilolite, both naturally occurring and activated, relative to water vapor.

The results of the research of the adsorption capacity of a number of sorbents of natural and synthetic origin for ammonium ions have been clustered. The natural zeolite of the Sokyrnytsia deposit, a synthetic sorbent based on the fly ash of Dobrotvir state district heat power plant, Al2O3, SiO2, as well as some types of soil: sandy soil, black soil, and clay were used in the research. Equations describing the regularities of adsorption processes depending on the type of sorbent were obtained. According to the obtained dendrograms, two main clusters of sorbents were identified.

An alternative method of purification of aqueous sulfide-alkaline effluents from sulfide and hydrosulfide ions by their adsorption with mixed sorbents based on activated charcoal and kieselguhr has been investigated. High adsorption efficiency of mixed sorbents for purification of model sulfide- and hydrosulfide-containing solutions has been established. The dependence of the extraction degree of sulfide and hydrosulfide ions from aqueous solutions on their concentration, adsorption time and sorbent mass used has been investigated.