Thèse soutenue au M2P2 fin 2024 : Mécanismes d’interactions entre la matière organique et minérale (phosphates) lors de la valorisation par liquéfaction hydrothermale : application aux digestats de méthanisation
Publications scientifiques au M2P2
2025
Antonello Tangredi, Cristian Barca, Jean-Henry Ferrasse, Olivier Boutin. Combining process severity and response surface methodology: a comprehensive approach to phosphorus speciation in sewage sludge hydrothermal treatment. Journal of Environmental Management, 2025, 381, pp.125239. ⟨10.1016/j.jenvman.2025.125239⟩. ⟨hal-05039217⟩ Plus de détails...
Phosphorus is essential for global food production, but intensive agriculture disrupts its natural cycle, increasing reliance on non-renewable sources. A sustainable alternative is recovering phosphorus from waste streams using thermochemical processes. This work investigates the hydrothermal treatment of sewage sludge digestate to explore phosphorus conversion and speciation, aiming to optimize solid by-product as fertilizer. Through a novel integration of response surface methodology and process severity modeling, the study examines the influence of process parameters (temperature, time) on phosphorus behavior. A sewage sludge digestate, sampled from a wastewater treatment plant, was treated in a batch reactor at temperatures from 250 to 350 °C for 5-45 min. Products were centrifuged into a solid pellet and process water, followed by characterization of their physicochemical properties. Results show that temperature and time significantly impact by-product characteristics and phosphorus speciation. Treatments at 250-300 • C promote organic phosphorus mineralization and increase soluble phosphate concentration, while treatments at 350 • C lead to greater phosphorus recovery in the solid pellet, mostly as calcium phosphates. This research provides a framework for sustainable phosphorus recovery, suggesting hydrothermally treated pellets as potential slow-release fertilizers. Future work should comprehensively investigate the effect of calcium addition on phosphorus precipitation as calcium phosphates.
Antonello Tangredi, Cristian Barca, Jean-Henry Ferrasse, Olivier Boutin. Combining process severity and response surface methodology: a comprehensive approach to phosphorus speciation in sewage sludge hydrothermal treatment. Journal of Environmental Management, 2025, 381, pp.125239. ⟨10.1016/j.jenvman.2025.125239⟩. ⟨hal-05039217⟩
Antonello Tangredi, Cristian Barca, Jean-Henry Ferrasse, Olivier Boutin. Effect of process parameters on phosphorus conversion pathways during hydrothermal treatment of sewage sludge: A review. Chemical Engineering Journal, 2023, 463, pp.142342. ⟨10.1016/j.cej.2023.142342⟩. ⟨hal-04303018⟩ Plus de détails...
Sewage sludge represents a renewable source of organic carbon and nutrients such as nitrogen (N), potassium (K), and phosphorus (P) that can be valorised through the recovery of energy carriers (e.g. biofuels) and fertilizers (N, K, and P precipitates). This review analyses>60 recent studies that have investigated P recovery potential from sewage sludge by hydrothermal processes. The effect of process parameters such as temperature, residence time, pressure, solid-to-liquid ratio, and addition of additives on P conversion pathways has been investigated by a critical discussion of the results published in the literature. Results show that temperature is the most influential parameter for P speciation and repartition: the increase in temperature appears to promote the increase in solid P recovery yield, the mineralization of organic P, and the conversion of non-apatitic P into apatitic P. The increase in reaction time has similar effects as temperature, but to a lesser extent. Solid P recovery yield and apatitic P fraction can be enhanced by increasing the medium alkalinity and by adding Ca-containing reactants. Non-apatitic P fraction can be increased by lower medium alkalinity, and by the addition of Fe-and Alcontaining reactants. The results of this review provide to researchers and practitioners in the field of sewage sludge management key elements for the best operation of hydrothermal reactors to improve the recovery of P and biofuels. Finally, some new research perspectives and technical challenges are proposed to improve the knowledge and the scaling up of the technology.
Antonello Tangredi, Cristian Barca, Jean-Henry Ferrasse, Olivier Boutin. Effect of process parameters on phosphorus conversion pathways during hydrothermal treatment of sewage sludge: A review. Chemical Engineering Journal, 2023, 463, pp.142342. ⟨10.1016/j.cej.2023.142342⟩. ⟨hal-04303018⟩
