COD reduction by TiO2/graphene photocatalytic treatment of ethylene dichloride in wastewater

Photocatalytic degradation of ethylene dichloride (EDC) wastewater was investigated in a batch photocatalytic reactor using titanium dioxide (TiO2)/graphene hybrid as the catalyst for the first time. The main advantage of this structure, in which graphene was used as a bed for TiO2, was that it enhanced the electron transfer considerably. The degradation in the organic waste was evaluated in terms of chemical oxygen demand (COD). The concentration of EDC, the amount of the photocatalyst, the concentration of graphene in the catalyst structure, and the pH of the solution were found effective in reaction efficiency. For an initial EDC concentration of 750ppm, the optimum conditions for EDC removal from the wastewater were 2g/l concentration of photocatalyst concentration, 1wt% concentration of graphene in the hybrid structure, and a pH of 4. The experiments were carried out at 5 degrees C. It was found that using this structure, only 4h of treatment was sufficient to obtain a considerable COD reduction. Increasing irradiation intensity from 100 to 200W increased EDC removal from 69.1 to 81.8%.