sorption

This paper reviews current trends in the reuse and effective disposal of bentonite clay sorbent (montmorillonite, as the main mineral in bentonite and palygorskite clays) after its application in wastewater treatment systems. Special attention is given to its potential applications in construction and polymer composites. A comparative analysis of the advantages and limitations of various approaches to bentonite regeneration, reuse possibilities, and effective disposal of the spent sorbent is conducted.

The paper is devoted to the study of the sorption properties of residual coal formed after hydrocavitation treatment of brown coal of the Olexandria deposit. The study aims to investigate the possibility of more efficient usage of brown coal processing products that have undergone cavitation treatment. Hydrocavitation of earthy brown coal provides complete and fast extraction of humus acids during extraction with the sodium hydroxide solution. At the same time, the residual coal is pulverized to the size of 10-20 µm.

The bentonite from the Ilnytsky deposit was modified by sorbtion of chitosan on the surface of its particles in an aqueous suspension. It was found that there is an optimal concentration of chitosan (at a constant bentonite content in the suspension) that maximizes the sorption rate of chitosan macromolecules, which leads to improved flocculation and sedimentation of the suspension. Additionally, it was demonstrated that the chitosan sorption on suspension particles significantly increases with increasing pH from 3 to 9.5.

The sorption of copper ions from a solution of copper(II) sulfate by the native form of natural clinoptilolite under mechanical stirring and under the action of ultrasonic radiation of different power and under different modes of process implementation (continuous and cyclic) was investigated. Based on the obtained results, it was concluded that ultrasonic vibrations significantly intensify the diffusion processes in the studied system.

The process of modification of natural clinoptilolite, pre-enriched by the main component, with manganese ions from nitrate solutions as precursors for obtaining manganese(IV) oxide was studied. The value of the sorption capacity of different fractions of clinoptilolite with respect to manganese ions at room temperature was determined, and the sorption rate and rate constants of this process were calculated. The influence of the concentration of manganese nitrate solution on the sorption capacity of certain fractions of zeolite was determined.

The influence of dispersion on the structural and sorption properties of the Transcarpathian clinoptilolite of the Sokyrnytske deposit was investigated by the method of complex thermal analysis. For a sample with a grain size of 0.14 mm, the effect of heat treatment on the ability to sorb water vapor was investigated. Thermal activation of clinoptilolite was carried out at temperatures of 200°C, 300°C, 400°C.The sorption capacity of natural and thermally activated clinoptilolite samples with relative to water vapor was investigated by thermal analysis.

Much of the sorbent used in the food industry is not re-used because it is difficult to regenerate and expensive. Also, the reuse of used sorbents involves their biological cleaning, which is due to the specificity of adsorbed materials. As a result, they are often stored off-site or disposed of in landfills, usually without authorization.  It is more promising to use such sorbents in waste water treatment, especially in the same food industry and in other industries where wastewater contains bioorganic substances.

The lyophilic properties of pyrocarbon, obtained by pyrolysis of worn automobile tires, in relation to oil, gasoline, benzene, hexane, water, and water-oil and water-gasoline emulsions were studied. The research was carried out by the method of a lying drop on the surface formed by pyrocarbon particles of different dispersion, by determining the contact angle of wetting. The value of this angle was determined by analyzing images obtained photographically. It was established that organic substances and water have a significant contrast in terms of the wetting of pyrocarbon.