Effect of Beech Sawdust Conditions Modification on the Efficiency of the Sorption of Anionic and Cationic Dyes

The article presents studies on the effect of the modification method of beech sawdust on the sorption capacity of the anionic dye Reactive Black 5 (RB5) as well as the cationic dye Basic Violet 10 (BV10). In the studies, the pH value, the dose of sawdust activated with epichlorohydrin and the dose of ammonia were determined for the efficiency of the removal of anionic and cationic dyes. In the next phase of the study, the pH and the dose of epichlorohydrin activator on the previously activated sorbent were determined. The modification proposed in the work, which consists in the amination of sawdust in direct reaction with ammonia, increased the efficiency of the sorption of anionic dyes. This reaction increased the positive charge on the surface of the sorbent by introducing -NH₂ groups, which led to an increase in the electrostatic attraction between the sorbent and the anionic dye, but to a decrease in the interaction between the sorbent and the cationic dye.