Photochemical degradation of nitrobenzene by S2O8 -2 ions and UV radiation

ABSTRACT: In this work nitrobenzene (NB) degradation was studied through an advanced oxidation process (AOP) by using a photochemical reactor and two kinds of oxidizing reagent: potassium persulfate (K2S2O8) and sodium persulfate (Na2S2O8), to promote generation of HO • radicals. It was determined the effect of different parameters on nitrobenzene degradation, such as: wavelength of UV lamps, concentration of oxidizing reagent, type of oxidizing reagent and number of UV lamps in the reactor. By using UV lamps with radiation wavelength of 254 nm, NB degradation reached almost 100 % meanwhile, irradiating at 350 nm resulted in < 35 % degradation. For experiments using UV lamps of 254 nm, the reaction rate increased with the radiant energy, being higher by using four UV lamps than two UV lamps for a reaction time of 60 min. The specific energy consumption for two UV lamps showed the lowest value being of 2626.0 KW.h/Kg of NB degraded.