Elissa MAKHOUL
defended her PhD thesis
“Elaboration and modification of porous calcium copper titanate membrane for water treatment using electro – oxidation via activation of peroxymonosulfate”
on 22 September 2023
Front of the jury composed of:
– M. David CORNU, Professeur, Université de Montpellier – Directeur de thèse
– Mme. Madona BOULOS, Professeur, Université Libanaise – Co-directeur de thèse
– M. Mikhael BECHELANY, directeur de recherche CNRS, Université de Montpellier – Encadrant
– M. Emmanuel MOUSSET, Chargé de recherche au CNRS, Université de Loraine – Rapporteur
– M. David RIASSETTO, Maître de Conférence, Université de Grenoble – Rapporteur –
– Mme. Karine GROENEN-SERRANO, Professeur, Université de Toulouse – Examinatrice
– M. Marc CRETIN, Professeur, Université de Montpellier – Examinateur
Abstract:
The growth in dangerous contaminants generated by pharmaceutical production facilities, hospitals, and human activities in water sources has become a major global problem. This necessitates the development of effective water pollution prevention and control methods due to their stability and persistence in water even at low concentrations. As a result, advanced oxidation processes (AOPs) are highly effective in removing various contaminants by oxidizing organic pollutants into harmless compounds. These processes generate hydroxyl radicals in situ, which act as powerful
non-selective oxidizing agents to degrade non-biodegradable organic molecules. Electrocatalytic oxidation, in particular, has been extensively studied due to its simplicity, ability to mineralize pollutants without causing secondary pollution, and high oxidation rates. The choice of anode and various factors influence the effectiveness of electrochemical oxidation. Furthermore, improving the electrochemical decomposition of persistent organic pollutants (POPs) involves not only modifying the electrode material but also exploring different active radicals. One notable approach is the sulfate radical-based AOP, which relies on the in-situ generation of ●SO4 radicals through the activation of peroxymonosulfate (PMS). Integration of sulfate radicals-based AOPs with electrocatalysis processes is one technique that has received a lot of interest. CaCu3Ti4O12(CCTO) is chosen as a perovskite material due to its high chemical stability, the presence of two metal oxide components, and its capacity to tolerate a wide range of substitutions and dopants. These characteristics make it a versatile material with customizable properties for water treatment.
In this study, the primary objective was to investigate the porous anode CCTO and examine the influence of the percentage of the porogen agent PMMA (poly (methyl methacrylate)) on the PMS-electrooxidation system for degrading paracetamol. The electrode was synthesized using a ball milling process. Once the optimal percentage of PMMA (30%) was determined, two modification processes were employed. The first modification process involved doping with different ratios of cobalt. This doping aimed to enhance the performance of electrooxidation by combining effects of Cu2+ and Co2+. The incorporation of cobalt into the electrode structure was expected to improve the electrooxidation process. The second modification method focused on the treatment of CCTO under different atmospheric conditions (nitrogen and hydrogen). CCTO-hydrogen achieve the highest efficiency for paracetamol degradation through PMS-electro-oxidation due to the reduction of CuO and TiO2 into Cu metallic and Ti9O17 magneli phase. Furthermore, the study also examined the impact of Dissolved and Colloidal Matter (DCOM) of the CCTO-hydrogen on the degradation of paracetamol. Remarkably, even in the presence of DCOM, the CCTO-hydrogen still exhibited the highest performance, achieving complete degradation of paracetamol within 10 min. Finally, a scale-up of the study was conducted, where a 5cm CCTO anode was tested as a connector in a continuous system for the treatment of 1 liter of paracetamol.
