Evaluation of degradation and kinetics parameters of acid orange 7 through wet air oxidation process

Abstract

Among the industrial effluents presenting constraints to traditional biological treatments, those from textile industries are of particular concern. Wet air oxidation is an effective process that significantly increases biodegradability of the treated effluent. In this study, the advantage of this process was tested for the treatment of acid orange 7, a dye molecule used as a model textile effluent. Different experimental conditions of temperature (200 to 300 °C) and duration of treatment were used to determine its degradation yield during the wet air oxidation process, at a total pressure of 30 MPa. All these conditions led to complete degradation of acid orange 7, but residual Total Organic Carbon always remained. Oxidation byproducts were identified by the means of GC and HPLC analyses. Acetic acid remains the major compound not oxidized. These experiments resulted in the proposal of a reaction scheme associated with kinetic constants. Finally, the optimal conditions for the improvement of the biodegradability of the effluent were determined. This wet air oxidation process could then be coupled with a biological treatment to obtain an overall degradation meeting the criteria for release into the environment.

An eco-friendly route for template-free synthesis of high specific surface area mesoporous CeO2 powders and their adsorption for acid orange 7

“…6 Therefore, it is essential to treat the industrial wastewaters containing AO7. [7][8][9] To date, many approaches have been conducted to control organic pollutants, such as biodegradation, [10][11][12] photooxidation, 13,14 chemical oxidation, [15][16][17] electrochemistry, 18,19 ultrasonic destruction 20,21 and adsorption. [22][23][24] Among these techniques, adsorption using adsorbents is considered to be one of the most convenient and cost-efficient methods.…”

Combination of chemical and biological processes to enhance the treatment of hardly biodegradable matter in industrial wastewater: Selection parameters and performances

“…Inhibitor effect experiments were performed with these compounds and it was shown that 3‐acetyl pyridine has higher toxicity (inhibitor effect) towards the Nitrobacteria and Nitrosomonas bacteria than the quinoline itself . Other examples include the different compounds produced through the WAO of AO7 (acid orange 7) dying molecule . It is, therefore, essential to identify potentially inhibitory or toxic compounds in the intermediate effluent.…”