Izvestiya of Saratov University.
ISSN 1816-9775 (Print)
ISSN 2541-8971 (Online)


adsorption

From traditional adsorption processes to bioremediation: Modern technologies for purifying natural waters from pollutants

The relevance of the study is determined by the fact that human activity has led to an increase in the anthropogenic impact on the environment. Various pollutants from a large number of discharges of municipal, industrial and medical wastewater are ubiquitous in the natural aquatic environment. Emerging pollutants are synthetic or naturally occurring chemicals or any microorganisms that are not normally monitored in the environment. But emerging pollutants may enter the environment and cause known or suspected adverse environmental or human health eff ects.

A Comparative Study of Benzene and Toluene Adsorption on KOH-Modified AR-A Activated Carbon: Effect of Concentration and Impregnation Ratio

This study compares the adsorption of benzene and toluene vapors on potassium hydroxide (KOH)-modified AR-A activated carbon (AC), considering their toxicological impact. The primary objective was to evaluate how different KOH concentrations and impregnation ratios influence the adsorption capacity and kinetics for these volatile organic compounds (VOCs). The AC samples were chemically modified using KOH at concentrations of 0.5 M and 1.0 M, using mass-to-volume impregnation ratios of 1:5 and 1:10.

Influence of time factor on adhesion and electrosurface properties of conductor and dielectric after plasma chemical activation of surface

The paper presents the results of measuring the surface adhesion fi gures of a dielectric (non-foiled glass-cloth-base laminate) and a conductor (foiled glass-cloth-base laminate) obtained by the adhesive tape tear-off method, as well as the surface potential depending on the time of storage of samples in natural conditions after activation of their surface by plasma-chemical etching. The obtained dependences are complex declining functions of time.

Study of adsorption of cadmium ions from solutions on natural and modifi ed diatomites

The search for new technologies for the purification of natural and waste water does not lose its relevance. Biologically, heavy metals are among the most dangerous pollutants. The highest toxicity among them has cadmium, causing serious environmental problems during technogenic pollution of the aquatic environment, and its extraction is an urgent task. The analysis of foreign studies on the extraction of cadmium ions is carried out.

The study of the physic-chemical properties of bentonite-based composite sorbents modified with carbon under the conditions of catalytic carbonization

The structural and sorption properties of composite sorbents based on natural bentonite modified with carbon compounds have been investigated. Modification of the initial bentonite by low-temperature (650°C) pyrolysis of sucrose in the presence of metal salts of the iron subgroup leads to a significant increase in the specific surface area of composite sorbents (up to 275 m2/g), this is due to low-temperature catalytic graphitization of the carbon fraction formed during pyrolysis.

Adsorption of Fe2+, Mn2+, Cu2+, Cd2+ Cations Using Granular Glauconite Sorbents

The adsorption properties of granular glauconite sorbents and their modified analogues against with respect to Fe2+, Mn2+, Cu2+, Cd2+ cations were studied and compared with natural untreated samples. The process was carried out in a static mode. The maximum adsorption of samples and the calculated adsorption equilibrium constants were determined. It was established that modified sorbents possessed the most activity adsorption against cations in pelleted samples. Modification was carried during sequential heat and acid-salt treatment.

Modelling of Drying Process of Natural Gas at a Pressure of 20–25 MPa through Aluminogel and NaA 4A Zeolite

Containment of water vapor in natural gas prevents its transportation and applying as an internal combustion fuel. The most demanded drying technology is adsorption at high pressure. The construction of a mathematical model for predicting the process is a significant task. Through a mathematical model of the process of water adsorption from natural gas at pressures of 20–25 MPa and temperatures of 5–40°C in the presence of NaA 4A zeolite and aluminogel, commonly used dehumidifier, optimal drying conditions were selected.

Application of Mathematical Model of Adsorber for the Development and Optimization of Adsorption Modes

A mathematical model of the adsorber was developed using the Toth equation. Microporous mordenite was synthesized to confirm model validation. The structure and characteristics of the obtained sorbent were confirmed by SEM, N2 adsorbtion, XRD and XRF methods. Adsorption of the hydrogen-methane mixture on H-form of synthesized mordenite was carried out at the pressure of 2 MPa and the temperature range of 20–35 °С.

The study of the physic-chemical properties of bentonite-based composite sorbents modified with carbon under the conditions of catalytic carbonization

The structural and sorption properties of composite sorbents based on natural bentonite modified with carbon compounds have been investigated. Modification of the initial bentonite by low-temperature (650°C) pyrolysis of sucrose in the presence of metal salts of the iron subgroup leads to a significant increase in the specific surface area of composite sorbents (up to 275 m2/g), this is due to low-temperature catalytic graphitization of the carbon fraction formed during pyrolysis.