Investigation on the sonocatalytic degradation of nitrobenzene using heterogeneous nanostructured catalysts in absence and presence of surfactant

Because of the extensive use and excessive release of various NB, economical and efficient methods for the treatment of wastewater and cleanup of petrochemical compounds are needed. This study focused on the sonocatalytic degradation of NB in aqueous solution assisted with H2O2 oxidant and nanostructured metal oxide catalysts, prepared in the absence of CTAB (series I), (Fe2O3-I, CuO-I, NiO-I, and Co3O4-I) and nanostructured metal oxide catalysts prepared in the presence of CTAB (series II), (Fe2O3-II, CuO-II, NiO-II, and Co3O4-II). The physicochemical properties of these catalysts were investigated via X-ray powder diffraction (XRD), transmission electron microscope (TEM), scanning electron microscope (SEM), and point of zero charge (PZC).The potential degradation feasibility for NB in US/nano metal oxide (series I and or series II)/H2O2 systems was measured by GC analysis at regular time intervals. Otherwise, some operational parameters such as ultrasonic irradiation time, solution pH value, H2O2 concentration, different weights of the nano-sized catalysts, NB concentration, leaching of the nano-sized catalysts, and reaction kinetics had been examined. It was found that H2O2 oxidant can effectively assist the sonocatalytic degradation of NB in the presence of nano-sized oxides (series I) and with more efficiency in the presence of nano-sized oxides (series II), and the effect of efficiency in degradation was changed in the order of (Fe2O3 > CuO > NiO > Co3O4). Therefore, oxides prepared in micellar solution were found to upgrade the economic aspect of NB degradation.