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.
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.
The statics and kinetics of albumin adsorption on natural zeolite of clinoptilolite structure have been investigated. The basic characteristics of zeolite have been determined. The method of albumin in a solution analysis was given. An isotherm of albumin adsorption was plotted and the Langmuir equation describing this isotherm was given. The presence of an external and pore diffusion adsorption mechanism has been experimentally established during the study of kinetics in a machine with mechanical stirring.
Zeolites were added to polyethersulphone (PES) membranes in order to enhance their capability of attracting creatinine. Zeolite was blended with PES by varying its doping concentration and time, and the mechanical properties of the resulting hollow fibre membranes produced under optimal concentration were characterised. The values of tensile stress, tensile strain and Young’s modulus, as well as the flux and rejection of the membranes were determined.
The adsorption of ammonium ions by natural zeolite and Al2O3 under static conditions has been investigated. The reason for changing the investigated solution pH during adsorption of ammonium ions on Al2O3 has been grounded. A phase diagram of the twocomponent system has been constructed and the composition of the adsorption system in the state of equilibrium has been determined. The thermodynamic calculations of the adsorption system Al2O3–NH4Cl–H2O have been carried out.
The results of research of the chemical activation process of clinoptilolite from Sokirnytskyi field are shown. As a result of the research, the effectiveness of the influence on zeolite hydrochloric and sulfuric acids are compared. It should be noted that the advantage is on the side of hydrochloric acid. It was established that the increase in the concentration of sulfuric acid and the time of zeolite processing leads only to the increase in the content of the amorphous phase.
It was established that natural and Ca modified zeolite inhibit steel corrosion in the medium of low acid rain. The Ca-containing zeolite inhibit the steel corrosion in the most effective way. The protective effectiveness of the alkyd coatings filled with zeolites can be placed in the following order: unmodified < with natural zeolite < with Ca-containing zeolite. Встановлено, що природний та модифікований кальцієм цеоліти інгібують корозію сталі в середовищі слабкокислих дощових опадів. Найефективніше інгібує корозію сталі Ca-вмісний цеоліт.