Heterogenous photocatalytic inactivation of B. stearothermophilus endospores in aqueous suspensions under artificial and solar irradiation

Inactivation of MS2 coliphage in sewage by solar photocatalysis using metal-doped TiO2

“…Conversely, in another work with the same metal dopants and Bacillus stearothermophilus endospores as the microbial target, natural sunlight proved to be superior to artificial light. However, it should be noted that the solar irradiation alone, without the addition of any catalyst, reduced the amount of colony forming endospores causing detrimental damages to the cells [13]. In the case of MS2 phages, the resistant nature of the virus requires significant high periods, which in certain cases may reach 24 h in order to observe a 4 Log decay with sunlight exposure [6].…”

“…Similar catalyst concentrations have been employed in other photocatalytic decontamination studies, which mostly refer to diverse microbial elimination namely, E. coli, Klebsiella sp., Pseudomonas sp. Enterococcus sp., MS2 bacteriophage and others in aquatic matrices [13][14][15][16][17][18]33,34]. Generally, optimal catalyst loadings vary among studies as they depend on many operating parameters, with the type of microorganism affecting efficiency to a considerable extent.…”

“…Moreover, these organisms are suggested as indicators of viral presence in the aquatic environment, as their basic features, namely, their size, morphology, structure and their overall behavior closely resemble those of enteric viruses destruction, impairment of enzyme and protein functions and nucleic acid denaturation [8][9][10]. However, in recent years, regulations mandate more stringent control of certain pathogens which exhibit high resistance to chlorine like parasites and viruses and of disinfection toxic by-products which may be toxic and genotoxic in the case of chlorination [11][12][13]. Although this technique remains the dominant disinfection process, other methods have emerged as quite effective in terms of water and wastewater disinfection.…”

Antimicrobial activity of cellulose-based nanofibers with different Ag phases

“…Silver (Ag) has been fabricated into nanostructures, such as nanoparticles (NPs), to maximize its chemical and biological activities [9][10][11][12]. Furthermore, by incorporating Ag NPs into nanofibrous structure, it is possible to produce functional nanofibers having optical, electrical, or catalytic properties, and subsequently extend their field of applications.…”

Ti/TiO2 nanotubes enhance Mycobacterium fortuitum, Mycobacterium chelonae and Mycobacterium abscessus inactivation in water

“…Photocatalytic processes may be a promising technique to successfully disinfect Mycobacterium ‐contaminated water. Photocatalysis using a solid catalyst such as titanium dioxide (TiO 2 ) is potentially viable – the process generates highly reactive hydroxyl radicals (•OH), which is the main oxidant inactivating microorganisms, including viruses, bacteria, spores, and protozoa . However, the quantum efficiency of photocatalytic degradation on bare titania is relatively low: it involves the transfer of photogenerated electrons and holes created within the semiconductor particles, but the problem is the competition from recombination of these charge carriers.…”