Recent progress in chemical water treatment has led to the development of advanced oxidation processes (AOPs). AOPs are based on the generation of hydroxyl radicals that can often achieve oxidative destruction of compounds refactory to the conventional ozonation or H2O oxidation. Therefore, industrial wastewaters from bulk drugs (diltiazem hydrochloride and ketoconazole) manufacturing processes were treated with UV/H2O2, UV/Fentons reagent, UV/Tio2 hetrogenous photo oxidation process as pretreatment step.