This project sought to build on previous WRF biofiltration research to further validate, optimize, and explore strategies to enhance biofiltration, with a specific focus on enhancing/facilitating the bioacclimation of filter media previously used in a conventional (chlorinated) filtration mode. Special attention was given to accelerating biological acclimation to manganese (Mn) removal while preventing legacy Mn from desorption and release. The overall objective of this study was to identify filter operational strategies for improved Mn control during the conversion to biofiltration, with a specific focus on achieving sustained biofilter treatment performance for Mn removal through both chemically and biologically mediated processes. The ability to monitor and characterize performance degradation or improvement through the conversion was also a critical component of the study.

 Characterize biofiltration under baseline and enhanced conditions at two facilities.  Further evaluate and optimize nutrient (phosphorus and/or nitrogen) and hydrogen peroxide augmentation to biofilters treating influent from different source waters and upstream processes.  Evaluate the impact of filter media selection.  Assess robustness of the optimized ozone/biofiltration processes.  Further develop and apply methods to monitor biofilter health via microbial methods.

The use of biological drinking water treatment processes for the treatment of surface water and groundwater has recently been increasing in North America. Biofiltration can simultaneously remove a wide range of dissolved organic and inorganic contaminants, while achieving particle removal goals. Organic compounds, including color and taste and odor (T&O)-causing compounds, are not only removed but also destroyed in this process. This can limit the formation of disinfection byproducts (DBPs) and lower regrowth potential in the distribution system. Operation of biofilters requires low energy input, minimal chemicals, and little waste production. Although biofiltration can provide numerous benefits, biofilter systems can be susceptible to hydraulic and water quality challenges, such as shortened runtimes, biological clogging, and breakthrough of contaminants such as T&O, manganese (Mn), and organic carbon. Drinking water biofilters are often de