Oxidation of aniline and nitrobenzene in fluidized-bed Fenton process

Abstract

To investigate oxidation of aniline (AN) and nitrobenzene (NB) by fluidized-bed Fenton process using AL[subscript 2]O[subscript 3] and SiO[subscript 2] as the carriers which have the pzc of 8.44 and 6.54, respectively. Optimum pH for AN and NB oxidation were 3.2 and 2.8, respectively. AL[subscript 2]O[subscript 3] was better than SiO[subscript 2] possible due to higher positive-charged surface at pH 2.8. In spite of comparable performance in organic oxidation, the fluidized-bed Fenton process was able to remove iron whereas the ordinary Fenton process could not. Empirical kinetic equations for the oxidation of individual AN and NB oxidation as well as the combination by fluidized-bed Fenton process were determinded and found to be inconsistency with those derived by stoichiometric equations. AN was found to be more vulnerable to hydroxyl radical oxidation than NB, i.e., when presenting at the same concentration, 72% of the generated hydroxyl radical reacted with AN whereas the rest of 28% were captured by NB. From the EDX analysis, iron oxide was crystallized onto the surface of the carriers and these iron-coated carriers could be reused successfully