Kinetic characteristics of textile wastewater ozonation in fluidized and fixed activated carbon beds

This study was to investigate the ozone oxidation of textile wastewaters in a fluidized or fixed granular activated carbon (GAC) bed. Experiments were conducted to examine the effects of various operating variables on the treatment efficienies of the combined ozonation and activated carbon adsorption. Ozonation was found to provide very efficient regeneration of exhausted GAC in the reactor, avoiding the costly ex situ GAC regeneration. It was also observed that the GAC acts not only as an adsorbent, but also as a catalyst in promoting ozone oxidation. The combined ozonation and GAC adsorption offers strong synergistic effects on the textile wastewater treatment. A generalized kinetic model consisting of multiple steps of ozonation and adsorption was proposed in this work to represent the combined process. The proposed adsorption/ozonation/desorption mechanism and the generalized kinetic model were shown to describe very well the combined treatment process. (C) 2000 Elsevier Science Ltd. All rights reserved.