Abstract
Activated carbon treatment and ozone oxidation were used for decolorization or total organic carbon (TOC) removal from an aqueous solution. Acid, neutral, and basic activated carbon (A-AC, N-AC, and B-AC) were prepared with particle sizes of 44 - 297 μm (S), 297 - 500 μm (M), and 500 - 840 μm (L), respectively. Methylene blue (MB) and orange II (ORII) were used as adsorbates, and the amount of MB or ORII adsorbed onto AC depended on the specific surface area of the AC. The adsorption data were fitted to the Freundlich and Langmuir equations, which suggested that the mechanism by which dye is adsorbed onto AC is that of monomolecular adsorption onto a heterogeneous surface. After ozone treatment, the MB and ORII structures were degraded and decolorized. However, TOC was not significantly reduced because the dye structure was broken down by ozone oxidation, which generated low-molecular-weight molecules but did not remove them. Activated carbon treatment after ozone oxidation was very effective for dye and TOC removal. This treatment enhanced the TOC removal by up to 20 - 30% from that achieved solely by ozone treatment.
