EN
The study was undertaken to analyze cyclic sorption and desorption of four reactive dyes: Reactive Yellow 84, Reactive Red 11, Reactive Black 5 and Reactive Black 8. onto chitosan beads. In all experimental series, dye and sorbent concentrations were constant and reached 50 mg/dm3 and 1 mg d.m./dm3, respectively. Determinations were conducted to investigate the effect of the sorbent on the effectiveness of dye removal. The number of feasible sorption/desorption cycles ranged from 6 to 3 and was found to depend on the type of dye tested. For all dyes examined, the quantity of dye accumulated onto chitosan beads and released from the solution was determined after each process of sorption and desorption.