The sorption of several types of dye on crosslinked polysaccharides derivatives

Crosslinked polysaccharides containing tertiary amine groups have been used for the recovery of various textile dyes from aqueous solutions. These polymers were prepared by reticulation of starch-enriched four using epichlorohydrin as a cross linking agent in the presence of NH4OH. The reaction was optimized and the products analyzed by IR and NMR techniques. Several sorption studies are presented, focusing on the nature of the polymer, the structure of dyes, and the concentration. The results show that these polymers exhibit high sorption capacities: the kinetics of sorption are dependent on the presence of amino groups and the variation in the amount of the sorption also depends on the nature of the dye. Physical adsorption in the polymer network and chemical interaction of the solute dyes via ion exchange and hydrogen bonding are both involved in the sorption process. The sorption mechanism is also due to the presence of dye-dye interactions. Experiments with mixtures of textile dyes show that the sorption of a given solute may be increased by the presence of another one. (C) 2002 Elsevier Science Ltd. All rights reserved.