Wet oxidation

About: Wet oxidation is a research topic. Over the lifetime, 3094 publications have been published within this topic receiving 61536 citations.

Removal of Gaseous Hydrogen Sulfide by a Photo-Fenton Wet Oxidation Scrubbing System

Abstract: In this article, a photo-Fenton wet oxidation scrubbing system was used to remove and oxidize gaseous hydrogen sulfide in an ultraviolet (UV)-bubbling column scrubber. The technical feasibility of ...

Regeneration by Wet Oxidation of an Activated Carbon Saturated with p-Nitrophenol

Abstract: The regeneration of a commercial activated carbon (AC) was studied using the wet air oxidation (WAO) process in the temperature range 150−180 °C and an oxygen partial pressure of 0.718 MPa. p-Nitrophenol (PNF) was used as the adsorbate. First, the oxidation process of PNF was studied. In the absence of AC, it was independent of the initial concentration of PNF at the conditions used in this work. The temperature and oxygen partial pressure exerted positive effects on the oxidation process. The activation energy of the PNF oxidation process and the reaction order with respect to oxygen were 134.8 kJ mol-1 and 0.55, respectively. The desorption process of PNF from the saturated AC was studied in the aforementioned temperature range. It was found to occur during the heating period, with an equilibrium being reached. The regeneration process was studied at these same temperatures, yielding an activation energy for PNF oxidation of 99.1 kJ mol-1. The isotherms of the virgin and regenerated AC and the phenol, m...

Catalytic wet oxidation of phenol with Fe–ZSM-5 catalysts

Abstract: Fe–ZSM-5 and Fe2O3/ZSM-5 zeolite catalysts were prepared and tested for catalytic wet oxidation of phenol. First, Fe–ZSM-5 and Fe2O3/ZSM-5 zeolite catalysts were prepared by the hydrothermal synthetic and incipient wetness impregnation method and characterized to determine the framework and extra-framework Fe3+ species. Second, the catalytic properties of Fe–ZSM-5 in the oxidation of phenol were systematically studied to determine the optimum technological parameters by investigating the effects of reaction temperature, pH, catalyst concentration and stirring rate on the conversion of phenol. In addition to the phenol conversion, selectivity to CO2 and concentration of aromatic intermediates in the oxidation of phenol with the two catalysts were analyzed under the same optimum conditions. Leaching of iron from the catalysts, as well as the catalytic stability of Fe–ZSM-5, was also tested. Finally, the kinetics of catalytic wet oxidation of phenol with Fe–ZSM-5 was studied. The experimental results showed that both the framework and extra-framework Fe3+ species were present in Fe–ZSM-5. The oxidation reaction with Fe–ZSM-5 was performed well at a temperature of 70 °C, pH of 4, catalyst concentration of 2.5 g L−1, stirring rate of 400 rpm and reaction time of 180 min. The conversion of phenol reached 94.1%. From the catalytic results of the two catalysts, it can be concluded that the framework Fe3+ species may be more efficient in phenol oxidation than the extra-framework Fe3+ species, the stability of Fe–ZSM-5 was better and a relatively low decrease in activity could be found after three consecutive runs. The activation energy of 27.42 kJ mol−1 was obtained for phenol oxidation with Fe–ZSM-5.

Caustic sulfide wet oxidation process

Abstract: A process for treatment of caustic sulfide liquor by wet oxidation in a nickel-based alloy system is described. The liquor is first analyzed for alkalinity consuming species and for nonsulfidic alkalinity. If excess alkalinity consuming species is present compared to nonsulfidic alkalinity, then additional nonsulfidic alkalinity is added to the raw liquor such that excess alkalinity is present during wet oxidation treatment, thus preventing excessive corrosion to the nickel-base alloy system.