Oxidation of nitrobenzene by ozone in the presence of faujasite zeolite in a continuous flow gas-liquid-solid reactor.

This work investigates the oxidation of nitrobenzene (NB) by ozone in the presence of faujasite zeolite. Experiments were carried out in a gas-liquid-solid reactor were ozone transfer and NB oxidation took place at the same time. Three configurations of the reactor were compared: empty, filled with inert glass beads and filled with faujasite pellets.

Enhanced bio-recalcitrant organics removal by combined adsorption and ozonation.

Removal of bio-recalcitrant and toxic compounds from wastewaters has been a major objective of industrial manufacturers for a few years. Due to the potential risk toward public health, regulations are becoming increasingly strict and classical treatments like biological treatments are not efficient. Other techniques such as incineration, oxidation or adsorption provide higher levels of removal but with a high energy and capital cost.

Ozonation of azo dye in a semi-batch reactor: a determination of the molecular and radical contributions.

Azo dye ozonation was carried in a semi-batch reactor to evaluate both the molecular and radical contributions of ozone on the dye decay. From two mass balance equations, the simultaneous determination of mass transfer, self-decomposition and solubility parameters of ozone were determined; thus establishing the steady state conditions in the experimental system. The results of kinetic studies showed that the decay of azo dye was a pseudo-first-order reaction with respect to dye concentration and the overall rate constant increased with an increase in the pH, however declined with an increase in the dye concentration.

Oxidation pathways for ozonation of azo dyes in a semi-batch reactor: a kinetic parameters approach.

In this study ozone and the H2O2/O3 oxidation system are used to decolorize aqueous solutions of Orange II (Or-II) and Acid Red 27 (AR-27). Investigations are carried out in a semi-batch bubble column reactor. A system of series-parallel reactions is proposed to describe the mechanism of dye oxidation.

Taking mass transfer limitation into account during ozonation of pollutants reacting fairly quickly.

Various situations observed when oxidizing organic compounds via ozone in a semi-batch reactor are illustrated. The resistance to the transfer of ozone from gas to liquid is accounted for using the film model. The mass balances are numerically solved simultaneously within the reactor and within the film to produce time dependent profiles of concentrations, Hatta, enhancement and depletion factors.