Naphthalene mineralization by supercritical water oxidation and determination of by-products using non-target analysis

Abstract

In this study, the fate of naphthalene was investigated with a supercritical water oxidation process (SCWO). Also, the effectiveness of different operating conditions including pressure, temperature, residence time and oxidant dose on the formation of by-products was determined. The experimental sets were determined by the experimental design program and the effect of the selected variables on the removal of the naphthalene was associated statistically. According to obtained results, naphthalene by SCWO process was mineralized up to 98.5%. Removal efficiencies in sub- and supercritical conditions were between 94 and 100%. Derivatives of aldehyde, propanoic acid, benzene acetic acid and benzofuran were detected as by-products at many experimental conditions and also, some intermediates with a molecular weight higher than naphthalene were determined. HIGHLIGHTS High mineralization in both sub- and supercritical conditions.; By-products of the binding reaction in low levels were detected.; The individual effect of oxidant dose, the dual effect of temperature and oxidant dose and second-order effect of time were found significant on the removal of naphthalene.;

Keywords

• by-products
• mineralization
• naphthalene
• supercritical water oxidation