WET AIR OXIDATION OF BISPHENOL-A, ISOPHORONE, p-HYDROXYBENZOIC ACID, AND p-TOLUIDINE OVER AN Ru/C CATALYST

摘要

Wet oxidation is a candidate wastewater-treatment technique, especially suitable when biological oxidation and incineration are inappropriate. In the present study, we investigate subcritical wet air oxidation (WAO) and catalytic WAO (CWAO) of four model compounds bearing different functional groups. Bisphenol-A, p-hydroxybenzoic acid, isophorone, and p-toluidine were the four chosen substrates representing classes of compounds phenols, carboxylic acids, ketones, and amines, respectively. Temperature and pressure were varied in the 423-473-K and 0.69-2.07-MPa ranges. A heterogeneous 5% Ru/C catalyst was used for CWAO. This catalyst was characterized using scanning electron microscopy, X-ray diffraction, Brunauer-Emmett-Teller analysis, and H_2 chemisorption methods. The performance of Ru/C for oxidative destruction of total organic carbon (TOC) was encouraging. Using TOC versus time data collected in the slurry reactor, kinetics of the reaction with isophorone were described using heterogeneous power law and Langmuir-Hinshelwood-type kinetic models. Our research has the potential to aid environmental engineers in effectively treating contaminated wastewater by WAO.