AWWA WQTC69494

By combining two complementary processes, advanced oxidation process (AOP) with artificial recharge and recovery (ARR), a synergistic hybrid system for removal of organic micropollutants (OMPs) will be created, according to the Dutch multiple barrier approach. For optimal synergy, both processes need to be understood in detail. The focus of this study is to understand the contribution of each individual process, AOP and ARR, towards the overall removal of OMPs. Pilot-scale experiments with AOP (UV/H₂O₂) were carried out in cooperation between Duinwaterbedrijf Zuid-Holland, Philips Research, Kiwa Water Research, Greater Cincinnati Water Works and AwwaRF. The pilot installation had a capacity of 5 m³/h, with a UV-dose of 700 mJ/cm² and a peroxide dose of 10 ppm. Low pressure and medium pressure lamps were tested in parallel. The general water quality improvements by ARR are known, but fundamental knowledge of the individual processes during ARR and associated effects on water quality is poor. If the contribution of individual processes in ARR are better understood, it will be possible to model water quality improvements and to compare these with related processes, like river bank filtration (RBF) and slow sand filtration (SSF). Experiments to obtain the characteristics of the different processes during ARR were performed in columns of 1 m height and a diameter of 0.05 m. Different soil layers (dune sand, peat, infiltration basin sludge) and redox states (aerobic, anoxic) are created and specific conditions are studied (chemical oxidation and reduction, biodegradation, and/or sorption). Includes 22 references, figures.