Investigation of Degradation Mechanism for dimethyl phthalate (DMP) in aqueous solution by using analytical methods

Abstract

Organic compounds called endocrine disruptorscause health problems by altering the functioning of the endocrine system in ahealthy organism or its future generation. In this study, phthalate acid esters (PAE’s) type of endocrine disruptors were chosen as model compounds and the degradation of dimethylphthalate (DMP) in aqueous solution was investigated under a variety ofreaction conditions using hydrogenperoxide. Inorder to increase the efficiency of degradation of DMP and intermediates whichmay be toxic, H2O2 was used as hydroxyl radical(oxidizing agents) sources in addition to water radiolysis products. To examine the effect of hydrogenperoxide concentration to decompose of DMP, different hydrogen peroxideconcentrations (0.6-4.8 mM) was chosen and as a result of the findings obtainedfrom the comparison of the results, 4.8 mM hydrogen peroxide was determined toprovide the optimum condition for decomposition of 25 mg L-1 DMPsolution. Changes in amounts of the remainsDMP, dissolved oxygen (DO), total acidity, and formaldehyde with irradiationtime were followed. The qualitativeanalysis of the DMP and the intermediates resulted from degradation of DMP wereperformed using a high performance liquid chromatography (HPLC), gaschromatography associated to mass spectrometry (GC–MS) and ion chromatography(IC). The results showed that 99.44% of DMP can be removed during 20min UV radiation time in the presence of 4.8 mM hydrogen peroxide.