Degradation of trace nitrobenzene in water by microwave-enhanced H2O2-based process

Abstract

To evaluate possible use of microwave-enhanced H2O2-based (MW/H2O2) process to degrade trace nitrobenzene (NB) in water, a series of batch experiments were conducted. The results showed that 2450MHz microwave irradiation significantly enhanced oxidative decomposition of nitrobenzene (NB) in a H2O2 system. About 90% NB was degraded by the MW/ H2O2 process in 30 min. Moreover, the MW/ H2O2 process could enhanced the oxidative degradation of NB even at relatively low temperature (50°C). When the initial concentration of NB was 300μg/L, the optimum ratio of H2O2 to NB and MW power were 70 and 300W respectively. The presence of humic acid significantly increased H2O2 dosage. The ultraviolet absorbance at 254 nm (UV254) indicated degradation of NB was stepwise and some intermediates were produced. The gas chromatography-mass spectrometric (GC-MS) analysis showed that main intermediates were nitrophenolic and carbonyl compounds.