Solar Photocatalytic Removal Of Metal Ions From Industrial Wastewater

摘要

This article describes the photocatalytic reduction and deposition of four metal ions Cr(Ⅵ), Ni(Ⅱ), Zn(Ⅱ), and Cu(Ⅱ) present in the wastewater from a chrome plating industry using solar energy irradiated TiO_2. A parabolic trough reactor was used to carry out the reaction. Experiments were carried out to find an optimum dose of hole scavenger used (citric acid). The adsorption and reduction of the metal ions at different pH values was also investigated.rnIt was observed that the solar photocatalytic process was effective in removing most of the metal ions in specific reaction conditions. Alkaline pH was found to be more suitable for removal of nickel and zinc. However, Cr(Ⅵ) reduced completely even at catalyst concentrations as low as 0.5 mg/L at pH 2. Maximum reaction was completed in the first 4 h of solar exposure.