Advanced physicochemical processes for wastewater treatment: from combined sewer overflows to micropollutant removal

This thesis addresses the critical challenges posed to aquatic ecosystems by Combined Sewer Overflows (CSOs) and persistent Organic Micropollutants (OMPs). The research is structured around two primary pillars: the development of a compact physicochemical treatment for CSOs and the validation of Rapid Small-Scale Column Tests (RSSCTs) for predicting Granular Activated Carbon (GAC) performance.Initially, a novel process combining 1 µm filtration with sequential ion exchange was designed, utilizing molecular sieve MS13X for cation exchange and Sorbacid 911 for anion exchange. Validated through on-site pilot testing during real rain events, the system demonstrated exceptional robustness despite material pelletization effects. It achieved removal efficiencies exceeding 90% for Total Suspended Solids, BOD5, Total Phosphorus, and metals (Cu, Zn), along with over 70% removal for ammonium and phosphate.Simultaneously, the study validated RSSCTs as an accelerated method for predicting GAC efficiency in removing OMPs from ozonated effluent. By comparing three years of historical pilot-plant data with laboratory results using Cyclecarb 401V, the Fractal-like Clark model emerged as the most accurate fit (R2 > 0.91) for the observed asymmetric breakthrough curves. The application of a specific empirical adjustment factor to the kinetic exponent allowed for the successful alignment of RSSCT predictions with full-scale data. Consequently, this work delivers a validated, compact technology for effective nutrient and solids removal in CSOs and establishes a refined, cost-effective methodology for scaling GAC adsorbers, offering practical solutions for advanced wastewater management.