zeolite

In detail, this study analysed the kinetics of ammonium ion adsorption under dynamic conditions in the "clinoptilolite -ammonium ion" system. The work includes constructing a mathematical model of this process, which allows us to estimate and predict its essential characteristics. Calculations of mass transfer coefficients revealed their dependence on the intensity of medium mixing. A significant result is that ion exchange occurs in externally diffusion and intradiffusion regions.

The paper presents the results of the study of the statics of adsorption of surface-active substances from model solutions by activated carbon and zeolite. The results of photometric determination of the concentration of anionic surfactants before and after adsorption are presented. The results of adsorption capacity calculations are presented. The experimental results using the program (Langmuir 1.03) were numerically calculated. Sorption isotherms of sodium dodecyl sulfate indicate the mechanism of monomolecular physical adsorption.

The article is devoted to the study of the prospects of using compost with sewage sludge in the raw material for the recultivation of disturbed lands. A special installation was used for bio-composting, which allowed controlling of the process parameters. The results of bio-indication of composts obtained under different conditions of compositions of the raw material mixture are given. Based on the analysis of the results of bio-indication, the optimal composition of the raw material mixture using "fresh" and "old" sewage sludge is established.

Batch experiments are applied to determine the effectiveness of zeolite addition on the characteristics of wastewater of the oil industry and operational factors. The concentrations of heavy metals were measured using an atomic absorption spectrophotometry. Results have shown that 2.5 g/L of zeolite at a speed of 270 rpm, 6.5 pH would result in about 99% removal efficiency.

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.

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 purpose of this work was to study the process of adsorption of phosphate on natural and synthesized sorbents, such as aluminosilicates. The sorption properties of natural zeolite for phosphate under static and dynamic conditions were investigated. The zeolite on the basis of the coal fly ash of Dobrotvorskaya heat power plant was synthesized and modified. The equilibrium values of adsorption capacity were determined, and the corresponding isotherms were constructed at a temperature of 20° C. The kinetics of adsorption under mechanical mixing conditions was investigated.

Among the large number of well-known and widely used active mineral additives of natural and artificial origin, zeolitic tuffs, an aluminosilicate with microporous framework structure, are of a great interest. Porous active mineral additives also include expanded perlite, which is obtained by thermal treatment of natural perlite – alkaline aluminum silicate glass. The activity of zeolite and perlite is connected to their ability to react with Са(ОН)2 and SO42-. In addition to the composition, their dispersion also has a significant impact on the activity level of mineral additives.

The hydrogen adsorption and desorption isotherms of multiwalled carbon nanotube sample (MWCNT), an iron loaded multiwalled carbon nanotube (Fe_MWCNT), two zeolites (Na_Y_Zeo and NH4_Y_Zeo) and MCM-41 were measured at 77 K and atmospheric pressure by using the volumetric adsorption apparatus. The adsorption data were evaluated by several isotherm equations such as Langmuir, Freundlich, Temkin and Harkins-Jura isotherm models but were best described by the Freundlich isotherm model as it gave the highest correlation.