ENVIRONMENTAL-MANAGEMENT OF TEXTILE AND METALLIC INDUSTRIAL EFFLUENTS

Management of textile and metallic effluents rich in omega chrome red ME, metaomega chrome orange GL, omega chrome fast blue B, and Cr (VI) and Cd (II), respectively, was carried out using wollastonite as an adsorbent. Batch adsorption experiments were performed for removal studies at different initial adsorbate concentrations, temperatures, and pH. A reaction kinetic study was undertaken by considering adsorption of the pollutant species on the outer surface as well as diffusion within the pores of the adsorbent. The mass transfer coefficient was calculated to explain the results. The effect of pH on the removal of the above adsorbates has been clarified on account of aqua-complex formation and subsequent acid-base dissociation, considering various surface site reactions. A Langmuir isotherm model fits the equilibrium data well. An attempt has been made to develop models correlating percentage uptake with the principal variables. (C) 1994 Academic Press, Inc.