Ongoing theses

Student Name : Manon GUYOT
Thesis Title : Precursors of Ferrous Phyllosilicate Crystals
Thesis Supervisor : Patrick DUTOURNIE
Co-Supervisors : Liva DZENE

Abstract : In operational systems, material damage due to corrosion or performance loss due to deposit formation can occur when silicic and ferrous species are present in solution. Phyllosilicate formation can occur, leading to further material degradation. The environmental conditions (aqueous concentrations, pH, Eh, temperature, etc.) for the formation of these phases are poorly understood. The lack of knowledge makes it impossible to reduce or avoid the degradation of materials and improve the durability of systems. The objective of the project is to understand the mechanisms of condensation reactions leading to the formation of phyllosilicates and to identify the precursors for the formation of iron-rich phyllosilicate crystals. To this end, an analysis of the in-situ solution will be carried out during the aging phase and hydrothermal synthesis (Eh, pH, conductivity), followed by the analysis of the ex-situ solution after separation of the precipitates from the supernatant (atomic absorption spectroscopy, UV-VIS). This analysis will be supplemented by an analysis of the precursors and synthesis products (X-ray diffraction, transmission electron microscopy, chemical analysis) and compared to the models obtained by the various mass balances. For simple solids such as metals and oxides, the crystallization mechanism is rather well understood. However, for porous and more complex solids such as zeolites, cementitious phases, and clay minerals, different crystallization mechanisms have been suggested. A debate on the existence of different types of precursors and the role of different silicon species in the crystallization process is still ongoing. The results of this study will contribute to the knowledge of the formation mechanisms of these solids. A better understanding of the formation mechanisms of phyllosilicates would make it possible to limit or prevent their formation in operational systems and to advance knowledge on the crystal formation of porous solids.

Student name : Ansem Bel Haj Rhouma
Thesis Title : Conversion of shrimp waste into carbonaceous materials by pyrolysis and hydrothermal carbonization for environmental and agronomic recovery
Thesis Supervisor : Mejdi Jeguirim / Leila ElBassi
Co-Supervisors : Mohamed Zbair

Abstract :
In the context of crustacean production, shrimp shells are an abundant and largely underutilized by-product. The global seafood industry generates millions of tons of shrimp shell waste each year, particularly in regions where shrimp farming and processing are essential to the economy, posing a serious threat to water resources, soil, flora and fauna, and human well-being. In recent decades, waste management concepts and priorities have been rethought to develop sustainable and environmentally friendly management strategies, adhering to the principle of the circular economy. Therefore, using a recycling and resource recovery approach, the optimization of the thermochemical conversion of shrimp shell waste into high-value pyrochar/hydrochar/biofuels is considered. The agronomic valorization of biochar/hydrochar for agricultural soil remediation will be carried out using a sustainable agriculture and circular economy approach. An environmental recovery of synthesized and optimized biochars (in raw or activated state) for the adsorption of pollutants in aqueous and/or gaseous effluents will also be carried out.

Student Name : Aurélie DUMONT
Thesis Title :
Thesis Supervisor : Jocelyne BRENDLE
Co-Supervisors : 
Abstract :