Sorption equilibrium of selected azo dyes onto low-cost sorbents (original) (raw)

In the paper, equilibrium of sorption of s elected azo dyes onto natural sorbents was studied. The sorbents included birch chips, rye straw, hemp fiber and cellulose. The materials were first subjected to initial heat and chemical processing. Sorption studies were carried out for selected azo dyes, i.e. Reactive Blue 81, Reactive Red 120, Direct Black 22 and Direct Orange 26. An advanced examination under infrared light was performed for the analysed systems, which allowed for the determination of the nature of the dye-sorbent bond. In most cases, the bonds were a result of physical adsorption on the surface and in the micropores of the material.