Adsorption de colorants ioniques sur des fibres de laine carbonisees

The study of the adsorption of an acid dye (AB‐80) and of a basic dye (BR‐22) has been carried out on charred woollen fibres, with a view to using that industrial waste material in the treatment of liquid effluents. The authors have first studied the dye diffusion; the diffusion of AB‐80 appeared much slower than that of BR‐22, due to the steric cumbersomeness of the AB‐80 molecule. As a result, the temperature effect on the diffusion, owing to its influence on the dye aggregation, was clearly more pronounced for AB‐80 than for BR‐22; that fact was confirmed by the determination of adsorption isotherms at different temperatures. Under favourable conditions, the curves indicated satisfactory adsorption values; as they were cither of type H (AB‐80) or L (Br‐22), they also indicated the efficiency of the aforesaid fibres in the treatment of slightly‐concentrated effluents. The above finding has been verified by a column treatment of an AB‐80 solution; it then showed the very strong influence of the contact time as well as a wall effect on the effluent purification. In the study conclusion, the results obtained in the treatment of an industrial effluent in a stirred reactor are presented.