Studies on the Application of Fenton (FeSO_4 + H_2O_2) and UV/Fenton for the Degradation of p-Anisaldehyde, 2-Aminothiophenol and Dimethylsulfoxide Present in Waste- water From Bulk Drug Manufacturing Processes

摘要

Hydrogen peroxide (H_2O_2) is a strong oxidant and its application in the treatment of various inorganic and organic pollutants is well established. However, H_2O_2 alone, is not effective for high concentration of certain refractory contaminants because of low rates of reaction at reasonable H_2O_2 concentrations. Improvements can be achieved by using transition metal salts (for example iron salts) or ozone and UV-light can activate H_2O_2 to form hydroxyl radicals, which are strong oxidants. Oxidation processes using activation of H_2O_2 by iron salts, classically referred to as Fenton's reagent is known to be somewhat effective in the destruction of many hazardous organic pollutants in water. In this work, Fenton/UV oxidation of refractory toxic organics p-anisaldehyde, 2-aminothiophenol and dimethylsulfoxide in wastewater of diltiazem hydrochloride and ketoconazole bulk drugs manufacturing process, respectively has been investigated using Fenton reagent along with low intensity UV radiation. Laboratory scale experiments were carried out using a 1000 mL 16W photo reactor. The results indicate that the Fenton/UV advanced oxidation process is an effective pre treatment method for industrial wastewater containing p-anisaldehyde, 2-aminothiophenol and dimethylsulfoxide having COD values as high as 70000 mg/L.