engleski

Degradation of azo-dye aqueous solution using TiO2 nanoparticles irradiated with natural solar and artificial solar-like radiation

Wastewaters containing synthetic organic dyes may be harmful to the environment and living organisms and it is very important to remove or degrade them prior to discharge into the environment. Heterogeneous photocatalysis, as one of the Advanced Oxidation Processes (AOPs), could be effective technology in the oxidation/degradation of organic dyes. In this study we used nanoparticles of TiO2 as the semiconductor photocatalysts for the degradation of Congo Red dye aqueous solution (CR). Since TiO2 particles are activated by UV-A radiation, two sources of UV radiation were used – natural solar radiation (contains 3-5% UV-A) and artificial, solar - like radiation, in the form of an UV lamp. Optimal dose of TiO2 of 500 mg/L was determined with artificial lamp experiments and this dose was used for the solar degradation process. In both cases significant potential for the degradation of CR was observed – total decolorization of the solution was achieved within 20-120 minutes. Degradation experiments were followed by changes in absorbance and in total organic carbon content of the solution. CR irradiation without TiO2 nanoparticles in both cases caused no observable changes of the solution.

azo dye; Congo Red dye; photocatalysis; solar radiation; artificial solar-like radiation

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