Enhanced photocatalytic oxidation of As3+ using titania nanoparticles for arsenic removal from water

Excessively high arsenic concentration in natural water and industrial wastewater is now a threatening problem for many countries especially Bangladesh, India, Germany, China and Turkey [1]. Titanium dioxide, a well-known adsorbent material, has been extensively tested for arsenic removal from water. However, arsenate ions (As5+) adsorbs more strongly onto the solid phase of adsorbent than arsenite ions (As3+). Therefore, the effectiveness of TiO2 nanoparticles in removing As3+ species from water have been enhanced by the photocatalytic oxidation in the presence of oxygen in ultraviolet (UV) light. In the present study, the photocatalytic oxidation of As3+ to As5+ is investigated in UV-illuminated TiO2. Batch adsorption experiment was carried out to analyze removal capacity of the TiO2 nanoparticles with and without presence of photocatalytic oxidation reaction and the adsorption isotherms were obtained. Keywords: Arsenic; Photocatalytic oxidation; Adsorption; Titanium dioxide nanoparticles [1] D. Mohan, C.U. Pittman Jr, Arsenic, Journal of Hazardous Materials , vol.142, 2007, 1–53.