Treatment of biofilms and opportunistic pathogens in simulated drinking water distribution systems using UV LEDs

Abstract

Biofilm formation in drinking water distribution systems (DWDS) has important implications for public health due to the potential proliferation of opportunistic pathogens (OPs). To inhibit the formation of biofilms and OPs in DWDS, Ultraviolet Light Emitting Diode (UV-LED) technologies show great promise due to their small footprint and versatility. This research aimed to expand the understanding of biofilm growth in DWDS and the application of UV LEDs to inactivate them. This thesis examined: (1) the inactivation of Legionella pneumophila and Pseudomonas fluorescens in CDC biofilm reactors on cast iron and stainless steel coupons and (2) the inactivation of tap water natural microbiome biofilms (NMB) grown on biostud reactors. Then, organisms were cultured and subsequently exposed to UV LEDs at 280 and 365 nm. Overall, organisms were more sensitive to 280 nm; however, 365 nm could be further investigated for possible photolytic reactions. Further work should consider scaling.