Sonophotocatalysis of 4-Chloro-2-Nitrophenol Using Tio2 Present In Pharmaceutical Industrial Wastewater

Abstract

Abstract The use of conventional water and wastewater treatment processes becomes increasingly challenged with the identification of more and more contaminants due to rapid growth of population and industrial activities, and which leads to diminishing availability of water resources. So, advanced treatment technologies have emerged in last decade to remove various potentially harmful compounds that could not be effectively removed by conventional treatment processes. Pharmaceutical residues are detected in several compartments of the environment, especially the aquatic one. Most of them enter the environment by treated and untreated wastewater. New purification techniques are under investigation to find ways for eliminating these substances effectively. These days considerable interest has been shown by researchers all over the world in the field of advance oxidation processes. Advanced oxidation processes are those groups of technologies that lead to hydroxyl radical (.OH) generation as the primary oxidant. These radicals are produced by means of oxidizing agent such as H2O2 and O3, ultraviolet irradiation, ultrasound, and homogeneous or heterogeneous catalysts. In this process a new application of ultrasound on the photocatalysis i.e. Sonophotocatalysis are considering these days. It is for improving the performance of photocatalytic degradation of organic and inorganic contaminants in aqueous streams. Basically Sonophotocatalysis is the combination of two AOP’s i.e. Sonolysis (use of ultrasound) and photocatalysis (use of UV). A lot of research has been done on this technology in the recent years for the degradation of compounds like phenols and substituted phenols, alkyl halides, aromatics halides, substituted halides, inorganic chemicals, dyes, herbicides and pesticides etc. and this treatment technology shows that it has potential for the degradation and mineralization of these non-biodegradable compounds. So, we can say that Sonophotocatalysis has large capability for the water treatment. vi The purpose of this project is to see whether this sonophotocatalytic treatment is viable for treating pharmaceutical compound 4-cholro-2-nitrophenol or not. Titanium dioxide was used as Photocatalyst. Experiments were performed in UV light at optimized condition. The degradation of compound has been investigated in terms of various process parameters like catalyst dose, pH, and concentration of oxidant. In this case the catalyst concentration was optimized at .3g/200ml, pH at 7 neutral and oxidant concentration at 1ml/200ml of the sample. The results obtained were quit appreciable as it reduced COD from 980 to 40mg/l. The results of Sonophotocatalytic degradation of pharmaceutical compound showed that it could be used as efficient and environmental friendly technique for the complete degradation of recalcitrant organic pollutants which will increase the chances for the reuse of wastewater. The investigations demonstrate the importance of selecting the optimal degradation parameters for practical applications of this operation.