Colour removal from textile effluents using hardwood sawdust as an absorbent

Abstract

Abstract Decolourisation of a dilute solution of a basic dyestuff was carried out by using hardwood sawdust as adsorbent. At 80°C 85% decolourisation occurred within 100 min at an initial concentration ( C o ) of 200 mg dm −3 . There was a 44% reduction in contact time when the temperature was raised from 25 to 80°C. The rate parameter for different initial dye concentrations was found to follow the equation: k co =4.20C o 0.88 and the rate parameter for different mean diameter d m followed the equation k dm = 4.1 (l/d m ) 0.135 . The activation energy of the process was 9.83 kJ mol −1 which shows that the rate controlling step is intraparticle diffusion.