Optimization of Fenton’s oxidation of herbicide dicamba in water using response surface methodology

Abstract

In this study Fenton’s oxidation of dicamba in aqueous medium was investigated by using the response surface methodology. The influence of H<inf>2</inf>O<inf>2</inf>/COD (A), H<inf>2</inf>O<inf>2</inf>/Fe2+ (B), pH (C) and reaction time (D) as independent variables were studied on two responses (COD and dicamba removal efficiency). The dosage of H<inf>2</inf>O<inf>2</inf> (5.35–17.4 mM) and Fe2+ (0.09–2.13 mM) were varied and optimum percentage removal of dicamba of 84.01% with H<inf>2</inf>O<inf>2</inf> and Fe2+ dosage of 11.38 and 0.33 mM respectively. The whole oxidation process was monitored by high performance liquid chromatography (HPLC) along with liquid chromatography/mass spectrometry (LC/MS). It was found that 82% of dicamba was mineralized to oxalic acid, chloride ion, CO<inf>2</inf> and H<inf>2</inf>O, which was confirmed with COD removal of 81.53%. The regression analysis was performed, in which standard deviation (<4%), coefficient of variation (<8), F value (Fisher’s Test) (>2.74), coefficient of correlation (R2 = Radj2) and adequate precision (>12) were in good agreement with model values. Finally, the treatment process was validated by performing the additional experiments. © 2017, The Author(s).