Abstract

Abstract: Photocatalytic degradationemploying semiconductors as photocatalyst is a promising and attractive methodfor the removal of pollutants in wastewater. TiO₂ has beenidentified as the most effective and useful photocatalyst. However, theapplications of TiO₂ has been retarded by fast recombination ofelectron-hole pairs and their wide band gap which corresponds to the UV light.Therefore, the study with modifying TiO2 in order to reduce the electron-holerecombination and sensitization towards visible light is one of the currenthotspots in the photocatalyst research. Photocatalytic degradation experiments werecarried out using E. coli, UV light was mainly used as photon source.The proposed study aims at investigating the above mentioned aspects byconducting an in-depth study of E. coli degradation using commerciallyavailable, sol-gel synthesized and doped TiO₂. Experimental runswere carried out with varying inoculum levels of 1 ml/L, 10 ml/L, 20 ml/L andthis was fixed at 20 ml/L and also with varying concentrations of commerciallyavailable TiO₂ i.e. 0.05 g/L, 0.1 g/L, 0.5 g/L, 0.7g/L, 1 g/L and 2g/L in 100 ml and 1L total volume where 0.5 g/L was found to be optimum catalyst concentration for which the time takenwas 2 h to degrade. Degradation studies were also conducted with sol-gelsynthesized TiO₂ and Ag doped TiO₂ which took 9 and 6 minrespectively for the optimum 0.5g/L catalyst concentration. Also Ag doped TiO₂was tested under sunlight for which the degradation time was 30 min.

Keywords:Photocatalyticdegradation, Photocatalyst, sol-gel, Ag doped , E.coli