Photocatalytic color removal of reactive Congo Red dye by UV/nano-TiO2 process

Photooxidation with TiO2 photocatalyst is a relatively new technique that can be used to remove various contaminants from water. In this investigation, the efficiency of color removal from aqueous diazo congo red dye solution has been investigated in TiO2 nano-particles aqueous suspensions irradiated by artificial UV light. For this purpose, a series of batch photocatalytic tests were carried out with the same initial Congo red (CR) dye concentration by varying the amount of TiO2 added and the irradiation time. The doses of TiO2 were 0.25, 0.5 and 1.0 g/L. The wavelength of incident ultraviolet (UV) light for the photocatalytic oxidation was predominantly 254 nm. The decrease of CR concentration during photocatalytic decolorization was monitoring by means of UV-VIS spectrophotometer. It was observed that the degree of CR photodegradation increased as the dose of the photocatalyst increased with the best result achieved using a TiO2 dose of 1.0 g/L.