Bioaccumulation Dynamic by Crassostrea gigas Oysters of Viruses That Are Proposed as Surrogates for Enteric Virus Contamination in Environmental Samples

Copper Oxide Electrochemical Deposition to Create Antiviral and Antibacterial Nanocoatings

The impact of the reaction environment on the formation of the polycrystalline layer and its biomedical (antimicrobial) applications were analyzed in detail. Copper oxide layers were synthesized using an electrodeposition technique, with varying additives influencing the morphology, thickness, and chemical composition. Scanning electron microscopy (SEM) images confirmed the successful formation of polyhedral structures. Unmodified samples (CuL) crystallized as a mixture of copper oxide (I) and (II), with a thickness of approximately 1.74 μm. The inclusion of the nonconductive polymer polyvinylpyrrolidone (PVP) during synthesis led to a regular and compact CuO-rich structure (CuL-PVP). Conversely, adding glucose resulted in forming a Cu2O-rich nanostructured layer (CuL-D(+)G). Both additives significantly reduced the sample thickness to 617 nm for CuL-PVP and 560 nm for CuL-D(+)G. The effectiveness of the synthesized copper oxide layers was demonstrated in their ability to significantly reduce the T4 phage titer by approximately 2.5-3 log. Notably, CuL-PVP and CuL-D(+)G showed a more substantial reduction in the MS2 phage titer, achieving about a 5-log decrease. In terms of antibacterial activity, CuL and CuL-PVP exhibited moderate efficacy against Escherichia coli, whereas CuL-D(+)G reduced the E. coli titer to undetectable levels. All samples induced similar reductions in Staphylococcus aureus titer. The study revealed differential susceptibilities, with Gram-negative bacteria being more vulnerable to CuL-D(+)G due to its unique composition and morphology. The antimicrobial properties were attributed to the redox cycling of Cu ions, which generate ROS, and the mechanical damage caused by nanostructured surfaces. A crucial finding was the impact of surface composition rather than surface morphology on antimicrobial efficacy. Samples with a dominant Cu2O composition exhibited potent antibacterial and antiviral properties, whereas CuO-rich materials showed predominantly enhanced antiviral activity. This research highlights the significance of phase composition in determining the antimicrobial properties of copper oxide layers synthesized through electrodeposition.

Ozone, hydrogen peroxide, and peroxymonosulfate disinfection of MS2 coliphage in water

The control of viruses in water is critical to preventing the spread of infectious viral diseases. Many oxidants can inactivate viruses, and this study aims to systematically compare the disinfection effects of ozone (O3), peroxymonosulfate (PMS), and hydrogen peroxide (H2O2) on MS2 coliphage. The effects of oxidant dose and contact time on disinfection were explored, as were the disinfection effects of three oxidizing agents in secondary effluent. The 4-log inactivation of MS2 coliphage required 0.05 mM O3, 0.5 mM PMS, or 25 mM H2O2 with a contact time of 30 min. All three oxidants achieved at least 4-log disinfection within 30 min, and O3 required only 0.5 min. In secondary effluent, all three oxidants also achieved 4-log inactivation of MS2 coliphage. Excitation-emission matrix (EEM) results indicate that all three oxidants removed dissolved organic matter synchronously and O3 oxidized dissolved organic matter more thoroughly while maintaining disinfection efficacy. Considering the criteria of oxidant dose, contact time, and disinfection efficacy in secondary effluent, O3 is the best choice for MS2 coliphage disinfection among the three oxidants.