Abstract
A hybrid process for mineralization of aqueous aniline using Fenton and wet oxidation (FENTWO) is studied. It is important to have maximum conversion of βNβ atoms from the waste to N~2~. The conversion of input βNβ atoms in aniline to N~2~ was 15% during wet oxidation without the Fenton process and was improved to 50% with the Fenton process. Therefore, a hybrid process of Fenton followed by wet oxidation was studied for mineralization of the aqueous aniline stream. The parameters for the Fenton process were optimized (pH, catalyst, H~2~O~2~ to catalyst (FeSO~4~) ratio, quantity of H~2~O~2~). The waste obtained after the Fenton process was then treated by wet oxidation for mineralization by having homogeneous CuSO~4~ as the catalyst by keeping FeSO~4~ therein. This combined catalyst was found to be more effective for the degradation of the intermediates formed in the Fenton process. Wet oxidation (WO) was studied in the temperature range 473β513 K and the oxygen partial pressure range 0.345β1.38 MPa at pH 6.5. The kinetic data was modeled using a power law rate expression in terms of chemical oxygen demand (COD). The optimum temperature for formation of more N~2~ gas was found to be 493 K. The treated waste stream was found to contain oxalic acid using HPLC, and NH~4~^+^, NO~3~^β^ and NO~2~^β^ ions using ion chromatography analysis. Copyright Β© 2007 Society of Chemical Industry