Ultrasound-assisted degradation of p-nitrophenol using Cu-Mn mixed oxide as a heterogeneous Fenton-like catalyst

p-Nitrophenol is one of the most important nitroaromatic compounds which are a major class of environmental contaminants and widely used in the manufacture of agrochemicals, dyes and explosives. It is very toxic (LD50 = 250 mg/kg), mutagenic and carcinogenic and regarded as a priority pollutant by US EPA [1]. In the structure of p-nitrophenol, the nitro group, as electron withdrawing group, makes the electronic cloud density on the benzene ring greatly reduce, and results in electrophilic group to attack benzene ring with great difficulty, so that it is difficult to be degraded in nature [2]. Several treatment technologies have been studied for p-nitrophenol removal, such as adsorption [3], biological degradation [4] and electrochemical treatment [5]. However, some of used approaches are inefficient, expensive and limit their wide application in large scale. In this study, a novel nanocatalyst based on copper and manganese was prepared by a facile one-pot hydrothermal method and used as a catalyst for heterogeneous Fenton-like catalyst for degradation of p-nitrophenol. The Cu-Mn mixed oxide nanomaterial prepared by this method exhibits high catalytic activity for the degradation of p-nitrophenol. The nanocatalyst was characterized using scanning electron microscopy (SEM), Fourier transform infrared spectrometer (FTIR) and X-ray diffraction (XRD). The important factors affecting the degradation efficiency, including solution pH, catalyst dosage and H2O2 dosage were investigated.