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6934021 
Journal Article 
Sequential gas-liquid treatment for gaseous toluene degradation by Fenton's oxidation in bubble reactors 
Lima, VN; Rodrigues, CSD; Madeira, LM; , 
2020 
Journal of Environmental Chemical Engineering
ISSN: 2213-2929
EISSN: 2213-3437 
ELSEVIER SCI LTD 
OXFORD 
WOS:000545338000004 
A lab scale bubble reactor (BR) configuration was employed to evaluate the degradation of gaseous toluene by Fenton's oxidation under semi-batch mode operation (i.e., with continuous gas bubbling in the liquid phase where organics oxidation is carried out). A parametric study was performed for evaluating the effect of Fenton's process operating parameters, such as temperature and concentration of Fe2+ and H2O2 , in the removal of toluene from the gas stream. The maximum amount of toluene transferred (0.041 mol per liter of solution) was reached when the optimal conditions ([Fe2+] = 2.5 mM, [H2O2] = 20 mM, and T = 25 degrees C, at pH 3.0) were used after 120 min of reaction, yielding the highest average toluene absorption rate (5.78 x 10(-6) mol/L.s). The treatment of the gas stream increased, however, the organic load in the aqueous phase, so a subsequent treatment stage of the liquid was performed. Additionally, a scale-up of the sequential gas-liquid treatment for a bubble column reactor (BCR) was carried out for several cycles, up to almost 20 h. This strategy, making use of the Fenton's process for treating the toluene gas stream, with intermediate liquid oxidation, allowed to reach more gas treatment stages, while providing a final effluent that is non-toxic (0.0 % of inhibition of Vibrio Fischeri) and biodegradable.