Today water resources drinkable are more and more weak and fragile. One of the solutions, to meet the needs in waters is to reuse waters after waste water treatment plant (WWTP). At present, the quality of these discharges does not allow a direct re-use because these effluents contain pathogenic microorganisms and bio-refractory micropollutants (pharmaceutical products, solvent disruptors, surfactant agents, etc.). Membrane processes can used to treat WWTP effluents to produce waters of very good qualities because exempt from pathogenic and certain micropollutants. However, one of main limitation within the framework of reuse with an objective of zero liquid discharge is due to the fact that the membrane processes produce on one side high-quality waters and on the other concentrate the pollution in small volume.
The objective of the team GPM is to develop Advanced Oxidation Processes to treat nanofiltration retentate of waste water effluent. The interest of the use of the AOP results from the fact that retentates represent small volumes of water strongly concentrated. The study of the AOP applied to complex organic matrices raises scientific issues relative to reaction mechanisms and to physic-chemical quality of produced waters (with reaction products). Indeed, the multitude of elements (ionic, inorganic, organic, micropollutant) requires a rigorous approach to understand reaction mechanisms and their respective influence on the kinetics of degradation. The team thus attempts to answer these questions :
• What is the impact of the operating parameters on the retention of the target molecules in nanofiltration?
• What is the impact of the matrix on the performances of nanofiltration, in terms of flow and fouling?
• What is the effect of the composition of the nanofiltration retentates on the transfer parameters and on the pollutant removal kinetics during ozonation?
• Does the process allow a reuse of the retentate?
Stéphan BROSILLON, Julie MENDRET