Partenaires

Ampère

Supervisory authorities

CNRS Ecole Centrale de Lyon Université de Lyon Université Lyon 1 INSA de Lyon

Our partners

Ingénierie@Lyon



Search


Home > Thèses et HDR > Thèses en 2022

28/11/2022 - Intissar GASMI

by Laurent Krähenbühl - published on , updated on

Agenda

Ajouter un événement iCal

Intissar Gasmi defends her PhD on Nov. 28, 2022 at 2:00PM.
Place : Ecole Centrale de Lyon, amphithéâtre 203 (2e étage du bâtiment W1), Ecully

Parametric control and intensification of the degradation of emerging pollutants in aqueous phase by Sonochemistry, Galvano-Fenton and Sono-Galvano-Fenton.

Jury :
Rapporteurs : KORRI-YOUSSOUFI Hafsa (Paris Saclay) et EL BERICHI Fatima-Zohra (Univ. de Guelma)
Examinateur/trice : GONDRAN Chantal (Grenoble Alpes), MEROUANI Slimane (Constantine 3), HADDOUR Naoufel (Ampère, invité)
Directeurs de thèse : HAMDAOUI Oualid (Annaba) et BURET François (Laboratoire Ampère)

Abstract :
The aim of the present thesis is to study the degradation of micropollutants in water by advanced oxidation processes, namely Sonochemistry, Galvano-Fenton process and the possibility of their combination.
furosemide (FSM), a drug molecule, was chosen as a model micropollutant for the sonochemical degradation in a sono-reactor operating at 3 frequencies (585, 860 and 1140kHz) under variable acoustic power. This sono-reactor was characterised by calorimetric, pHmetric, conductimetric and ascorbic acid dosimetric methods. Maximum production of HO• radicals was obtained by adopting a frequency of 585 kHz and an acoustic intensity of 4.3 W.cm-2. The influence of several operating parameters on the sonochemical degradation of FSM introduced at a concentration of 10 mg/L was examined. The results showed that the degradation rate of the FSM increased significantly with increasing sound intensity in the range 0.83-4.3 W.cm-2, and decreased with increasing frequency in the range 585 -1140 kHz. It was also found that a more significant degradation is obtained under acidic conditions at pH 2. In terms of saturating gas, the degradation rate of FSM decreases in the order Ar > air > N2. HO• radical scavenging tests with tert-butyl alcohol and 2-propanol revealed that the HO• radical is the main actor in the degradation of FSM. In addition to these results, TOC analyses indicated that inspite of the total degradation of the FSM after 60 min of sonication, the degree of mineralisation remains limited to the order of 25%.
Furthermore, Malachite Green (MG) was chosen as a model micropollutant for the study of the patented Galvano-Fenton (GF) advanced oxidation process, a process that allows the production of electrical energy simultaneously. The study of the different GF design parameters revealed that the use of copper, as a low-cost material acting as the cathode in the galvanic coupling, provides the best treatment performance and energy production. The latter can reach the threshold of 220 mW.m-2 by increasing the cathode area from 6 to 36 cm2.
A parametric study was carried out to optimise the conditions for VM degradation by the GF process. It was shown that maximum degradation is achieved at a pH of 2 to 3, a temperature of 25 °C, and H2O2 concentration of 3 mM. Under these conditions, complete degradation of the MG was achieved after 30 minutes at an initial concentration of 10 mg/L. Numerical modelling was carried out to complement the experimental study and to reveal the mechanism of free radical formation and consumption, and in situ generation and regeneration of the Fe2+ catalyst, in the absence of an organic substrate and in the presence of a model azo dye, namely acid orange 7 (AO7). The strongest correlation with the experimental results, up to 93.5%, was obtained with the scenario stipulating a reaction mechanism that includes the reactivity of sulphate ions as well as the formation of iron complexes.
With the aim of developing a new hybrid treatment technique, it was opportune to carry out a combination of both previous processes that will allow, on the one hand, to use the electrical energy generated during the galvanic coupling and, on the other hand, to make the hybrid process partially or even completely reagent autonomous, through the in-situ production of the H2O2 reagent by the son-chemical route. Preliminary results have revealed the mechanisms of action of ultrasound in the hybrid process, and different configurations have been developed depending on the desired effect.

Keywords :
Micropollutants, Sonochemistry, Degradation, Galvano-Fenton, Energy, Combination.



View online : Texte complet