The adsorption of various metal ions (Hg2+, Ag+, Ni2+, Cr3+, A13+, Zn2+ and Pb2+) on wool carbonising waste has been investigated to assess its possible use as an adsorbent in water pollution control. Isotherms show that few metal ions (Hg2+, Ag+ and Ni2+) are adsorbed satisfactorily by this material. Moreover, the adsorption capacity of the plant material within the carbonising waste is higher than that of the keratin fraction. Equations fitting the experimental data can be used for the design of processing units.

In order to elucidate the mechanisms of adsorption of Hg2+, Aga+, Ni2+, Cr3+, AI3+, Zn2+ and Pb2+ on wool carbonising waste, the possible role of the various ionisable groups (-SH, -S03H, -OS03H, -COOH and -NH2) of the substrate has been considered together with the corresponding solubility products and dissociation constants of the metal salts thus formed.

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.

In order to elucidate the mechanisms of adsorption of Hg2+, Ag2+, Ni2+, Cr3+, Al3+, Zn2+ and Pb2+ on wool carbonising waste, the possible role of the various ionisable groups (‐SH, ‐SO3H, ‐OSO3H, ‐COOH and ‐NH2) of the substrate has been considered together with the corresponding solubility products and dissociation constants of the metal salts thus formed.

The adsorption of various metal ions (Hg2+, Ag+, Ni2+, Cr3+, Al3+, Zn2+ and Pb2+) on wool carbonising waste has been investigated to assess its possible use as an adsorbent in water pollution control. Isotherms show that few metal ions (Hg2+, Ag+ and Ni2+) are adsorbed satisfactorily by this material. Moreover, the adsorption capacity of the plant material within the carbonising waste is higher than that of the keratin fraction. Equations fitting the experimental data can be used for the design of processing units.