The adsorption of dyestuffs from aqueous solutions using activated carbon. iv. external mass transfer processes

The parameters affecting the mass transfer coefficients for external transport of dyes from water on to activated carbon particles have been studied. The external mass transfer coefficients have been determined and correlated as the dimensionless mass transfer term, Sh/Sc0.33. The dimensionless function has been found to vary linearly with agitation, initial dye concentration, particle size, adsorbent mass on log‐log coordinates, while reciprocal variation was obtained with absolute temperature. Activation energies were determined for the surface process, for the adsorption of Deorlene Yellow, Victoria Blue, Telon Blue and Disperse Blue 7 and found to be 26.5, 24.5. 25.4 and 74.6 kJ mol‐l respectively.