New prototype for the treatment of falling film liquid effluents by gliding arc discharge part II: Plasmacatalytic activity of TiO2 thin film deposited by magnetron sputterin

Abstract

A new prototype of Gliding Arc Discharge (GAD) generating cold plasma at atmospheric pressure and ambient temperature was performed to treat pollutant liquid films. This study focuses on the intensification of the electrical process by the immobilization of a thin layer of TiO2 inside the GAD reactor by magnetron sputtering technology. The deposited film was analyzed by X-ray photoelectron spectroscopy (XPS) and the wettability was estimated by measuring the water contact angle (WCA).Plasmacatalytic activity of the GAD-plate-immobilized TiO2 was evaluated by the plasma-treatment of AG25 anthraquinonic dye dispersed in aqueous solution. The discoloration and the degradation rates have been largely improved by the synergetic effect between the plasma of humid air and the deposited TiO2.In the end of three successive cycles (3×120min) of plasma-treatment, the TiO2 depletion rate was between 2 and 3%, which means a good stability of the coated plate. No significant Fe, Cr and Ti concentrations were found after 360min of GAD-discharge.The electrical plasma-discharge intensified by the magnetron sputtering technology seems to be adapted to the degradation of organic compounds such as AG25 dye.