Biofilm disinfection and control in drinking water processes

In drinking water, biofilms can be engineered to remove natural organic material, inorganic matter and other chemical contaminants. However, in distribution systems, high pressure membrane systems and other water treatment processes biofilms can result in increased head loss, be a source of unwanted microbial and/or chemical contaminants, and decrease water quality. This research aims to discover new techniques and strategies to control biofilms in water treatment and distribution through fundamentally-based research that can be translated into practice. This research program has been divided into the following three focus areas. 1) Disinfection of Pathogens in Distribution Systems. Dr. Gagnon's research group has worked with several leading international researchers on this complex problem and will focus its efforts on chronic pathogen occurrence and we will use molecular tools and proteomics to identify mechanisms that allow pathogens to grow under sub-lethal disinfectant conditions. 2) Understanding the Interactions between Inorganic Contaminants and Biofilms in Distribution Systems. While it is recognized that inorganic contaminants (e.g., arsenic) can be treated to below their reference levels at the plant but they are prone to accumulation in the distribution system. Thus there is a need to develop a better understanding of the ability of biofilms to accumulate inorganic contaminants. 3) Biofilm Control in High-Pressure Membrane Systems. Nanofiltration (NF) has demonstrated a great potential to mitigate disinfection by-products (DBPs) in the absence of additional chemical addition. This work will determine treatment strategies and/or chemical additives that can be used to mitigate biofilm formation on NF without compromising water quality goals and membrane integrity.