MODIFICATION OF WASTES OF PAN-FIBERS FOR ADSORPTION APPLICATIONS

Wastes of acrylic fibers were chemically modified in order to obtain a dsorbents. The fibers were thermally treated with aqueous solutions of H2SO4 or NaOH at various concentrations. The adsorption ability of th e modified acrylic fibers and commercial adsorbents for comparison rea sons was evaluated on the basis of dye-adsorption of methylene blue (h aving electron donor groups) and alizarin yellow (having mainly electr on acceptor groups). The chemical structure of the modified acrylic fi bers was determined by IR spectroscopy. The experimental results of th e dye adsorption were theoretically treated by using a diffusion-limit ed adsorption method, which was applied for short reaction times. Adso rption kinetics parameters and the diffusion coefficients were calcula ted. The electron donor-acceptor (EDA) interactions between the functi onal groups of the polymers and those of the dyes influence strongly t he adsorption process. The modified acrylic fibers adsorb both dyes be tter than the commercial adsorbents.