A.E. Rubin, Y. Shah, L.M. Gilbertson
Duke University,
United States
Keywords: carbon nitride, photocatalyst, disinfection
Summary:
According to a 2021 report by the Centers for Disease Control and Prevention (CDC), approximately 7.15 million cases of waterborne illnesses occur annually in the United States, resulting in 118,000 hospitalizations, 6,630 deaths, and an estimated $3.33 billion in direct healthcare costs. Although drinking water is treated effectively in the U.S., it is not sterile, and microbial contamination, particularly microbial-influenced biofilms (MIBs) within distribution pipes can persist. These biofilms harbor pathogens such as Legionella, Pseudomonas, and non-tuberculous mycobacteria, posing ongoing public health risks. An emerging alternative is the use of photocatalytic nanomaterials, especially carbon nitride (CN), which generate reactive species (RS) under visible light to inactivate bacteria; however, limited interaction time between the photocatalyst and bacteria in flowing water, and large amount of radical quenchers in real water remains a major barrier. To overcome this challenge, we designed a closed-loop continuous flow system to examine the efficiency of our improved supramolecular calcination approach to increase RS generation and disinfection efficiency in real tap water. The resulting material demonstrated effective inactivation of Pseudomonas aeruginosa in a concentration of 105 CFU/mL within 10-15 minutes only – significantly faster that previously reported literature, offering a promising foundation for future development of efficient, point-of-use water disinfection systems to safeguard populations at risk from persistent microbial contamination.