Inactivation photocatalytique de Escherichia coli par une suspension de TiO₂ sous irradiation UV-C à 254 nm
Publication Date : 14/04/2026
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Abstract :
In a context of increasing scarcity of drinking water and growing microbial contamination, this study investigates the use of heterogeneous photocatalysis as an advanced oxidation process for water disinfection. The process involves the coupling of ultraviolet (UV) irradiation with a titanium dioxide (TiO₂, Degussa P25) powder photocatalyst in a photocatalytic reactor. The efficiency of the system was evaluated for the inactivation of the pathogenic bacterium Escherichia coli, commonly used as an indicator of fecal contamination in water. Experimental results showed that TiO₂ alone, in the absence of UV irradiation, exhibited very limited bactericidal activity. In contrast, UV irradiation at 254 nm induced a progressive bacterial inactivation through photolysis. The combined UV/TiO₂ system produced a strong synergistic effect, leading to rapid and complete inactivation of Escherichia coli, with an optimal catalyst concentration of 0.8 g/L. This inactivation is mainly attributed to the generation of highly reactive hydroxyl radicals responsible for the degradation of bacterial cell membranes and DNA. This approach therefore represents a promising technology for water treatment and disinfection, particularly in regions facing limited access to safe drinking water.
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