Heterogeneous photocatalytic degradation of antiviral drug didanosine mediated by rose bengal and TiO 2 nanoparticles.

There is a great concern among the researcher to remove the problem of the persistent organic pollutants in wastewater. Pharmaceutical agrochemical and personal care products are generally considered Persistent organic pollutants. Therefore, it is a matter of concern to develop new techniques how to remove these pollutants safely at low cost. This study mainly focuses on the commonly used antiviral drug didanosine and one most commonly used dye rose bengal. In this study, an organic dye rose bengal and TiO 2 nanoparticles have been used in combination with UV light to achieve the photodegradation of selected pharmaceutical products and the dye was also degraded by using TiO 2 Nanoparticles. The formation of three oxidation products was detected by using a very popular separation technique thin layer and column chromatography. The isolated photoproduct was characterized by using advanced characterization techniques like FTIR (Fourier transform infrared spectroscopy), UV Spectroscopy, and Proton and 13 C NMR (Nuclear Magnetic Resonance spectroscopy). The role of singlet oxygen as an active species in this reaction was confirmed by using D 2 O as a reaction medium. The role of singlet oxygen in this photochemical reaction was also established by the addition of sodium azide. The TiO 2 nanophotocatalyst efficiently degrade the didanosine and rose bengal in the presence of the UV light. In the TiO 2 -induced photocatalytic degradation of didanosine and dyes, the hydroxyl and superoxide radical anion play a prominent role. The finding of this manuscript is very useful to develop an efficient low-cost method for the treatment of wastewater contaminated by antiviral drugs, similar pharmaceutical products and dyes. This study was also very helpful to establish a plausible mechanism behind the phototoxicity of the didanosine.