Texture and Sorption Characteristics of Bentonite-Based Sorbents

Abstract

Studies have been carried out by modifying local bentonites with acid and heat treatment, which activate the sorption properties, due to the cation exchange of the initial elements of montmorillonite minerals.

The physicochemical properties of natural bentonite and sorbents based on it have been studied. It was found that the modification of natural bentonite leads to a change in the chemical composition, structural and sorption properties. It is shown that modified sorbents based on natural bentonite are finely porous (nanostructured) objects with a predominance of pores with a size of 1.4-8.2 nm. The specific surface area of ​​the sorbents depends on the modification method and the amount of the modifying component introduced.

The relevance of the development is determined by the growing interest in the creation of new environmentally friendly sorbents from natural aluminosilicates. However, the lack of effective granulation technologies is a deterrent to the widespread use of bentonites for water purification, since clay minerals are subject to the dispersion effect in aqueous media.

Methods and materials: to justify the possibility of using the developed technology for granulating bentonite, as well as the obtained samples of sorbents in the process of water treatment, the mineralogical composition of the granules was studied by X-ray phase analysis, the analysis of the specific surface, porosity (pore volume, pore distribution along the radius) by the method of sorption and capillary condensation of gases, their chemical and mechanical resistance were determined. After studying the physical properties, the sorption capacity of the samples was evaluated.

Results: a detailed analysis of the physical and chemical properties of the developed sorbents showed that the developed sorbents meet the requirements of national standart and are effective for use both as an independent filter material and as a component in water treatment systems.

The selective sorption properties of bentonite clay samples from the Navbakhor deposit in the Republic of Uzbekistan were studied. Mechanical enrichment of the selected bentonite clay samples was carried out, and the parameters of their selective sorption with respect to phenol were determined. A comparative analysis of the sorption properties of natural and enriched samples of bentonite clay showed that the main mineral is montmorillonite.

The purpose of this work is to study the properties of sorption materials based on bentonite clay.