Determination of Physico-Chemical and Adsorption-Structural Parameters of Sawdust and Their Various Modifications at the Structural Level

Abstract

The purpose of this work was to determine some physicochemical and adsorption-structural parameters of sawdust and their modified analogues.Methods. To determine the physicochemical and adsorption-structural parameters of sawdust and their various modifications, gravimetric, potentiometric, titrimetric methods of analysis were studied.To study the structure of sawdust, a Nicolet iS50 IR Fourier spectrometer and an OmegaScope™-SPM microscope with a confocal Raman and fluorescence spectrometer were used. The creation of molecular structural formulas was carried out in the integrated ChemOffice software package in ChemDraw 3D.Results. The data obtained showed that the sorption capacity of sawdust depends on the type of modification and on changes that have occurred at the molecular level. The greatest changes occurred with the type of modification of sodium hydroxide, the greatest formation of hydroxyl and carboxyl groups was noted.The results of IR spectrometry indicate that changes in the structure of the modified sorbents indicate a possible improvement in the ability of sawdust to sorb, including direct dyes.To determine the physicochemical parameters of sawdust and their various modifications, such characteristics as humidity, pH of the medium, settling rates, swelling, porosity, and bulk density were studied.The determination of the clarifying ability and adsorption activity of sawdust of various modifications was carried out using methylene blue. All samples of sawdust exhibit sorption properties, they can adsorb molecules ranging in size from 0.63 to 1.26 nm.Determined adsorption activity for iodine, characterized by iodine number and adsorption activity. The adsorption activity for iodine differs significantly (5.874-13.494), which is due to the different mechanism of sorption on various modifications of the cellulose sorbentConclusion. In this work, it is confirmed that the modification of sawdust with substances having an acidic and alkaline environment will positively affect the degree of sorption of the sorbent. Sawdust modified with 1% and 5% NaOH has the highest sorption capacity.With the help of IR spectroscopy, it has been proved that in the process of modification, changes occur in the sorbents at the structural level.