부산대학교 도서관

The presence of dyes in aqueous system causes aesthetic pollution, hydrolysis or other chemical reactions leading to the formation of products which are non degradable, and accumulate in water. A number of methods have been devised for degradation of dyes in aqueous streams which can cater to the never ending necessities of water worldwide. The methods include biological treatment, chemical oxidation, electrochemical decomposition, photocatalytic and chemical coagulation, physical and physico-chemical treatment. These methods are successful to a certain extent. In the present work, an attempt was made towards the sonochemical degradation of azo dyes such as methylene blue and p-nitro phenol. Further sonication experiments were carried out in combination with advanced oxidation processes. Sonication was performed at 20 and 70 kW power ratings. Percentage degradation was found to increase with increase in power ratings. Degradation of azo dyes was improved in presence UV source. Maximum degradation was observed when sonication was carried out in presence of UV source and hydrogen peroxide which was used as an oxidant. Increase in dye concentration decreased degradation rate and decrease in pH (acid medium) increased the degradation rate.