Advanced Oxidation Processes for Water and Wastewater Viral Disinfection. A Systematic Review

Abstract

Water and wastewater virological quality is a significant public health issue. Viral agents include emerging and re-emerging pathogens characterized by extremely small size, and high environmental stability. Since the mainly used conventional disinfection methods are usually not able to achieve complete disinfection of viral and other microbial targets, in real water and wastewater matrices, effective strategies for the treatment, use and reuse of water and the development of next-generation water supply systems are required. The scope of the present systematic review was to summarize research data on the application of advanced oxidation processes (AOPs) for viral disinfection of water and wastewater. A literature survey was conducted using the electronic databases PubMed, Scopus, and Web of Science. This comprehensive research yielded 23 records which met the criteria and were included and discussed in this review. Most of the studies (14/23) used only MS2 bacteriophage as an index virus, while the remaining studies (9/23) used two or more viral targets, including phages (MS2, T4, T7, phiX174, PRD-1, S2, ϕB124-14, ϕcrAssphage) and/or Adenovirus, Aichivirus, Norovirus (I, II, IV), Polyomavirus (JC and BK), Sapovirus, Enterovirus, Coxsackievirus B3, Echovirus, and Pepper mild mottle virus. The vast majority of the studies applied a combination of two or more treatments and the most frequently used process was ultraviolet light-hydrogen peroxide (UV/H 2 O 2 ) advanced oxidation. The review is expected to highlight the potential of the AOPs for public health protection from the waterborne viral exposure.

Clay-Supported Metal Oxide Nanoparticles in Catalytic Advanced Oxidation Processes: A Review

“…The higher TOF was achieved with a smaller amount on the active catalytic site [ 78 ]. Interestingly, the synergic effect between active nanoparticles and the support leads to better reusability and recyclability [ 79 , 80 , 81 ].…”

“…The metal-to-clay ratio determines much of the catalytic and photocatalytic activity, governing the physicochemical character of pillared clay. From many studies, such as research on the synthesis of TiO 2 -pillared montmorillonite and SnO 2 -pillared montmorillonite, it can be concluded that the metal-to-clay ratio is not linearly correlated with increasing either the physical characteristics or the catalytic performance of the pillared clay, but it has an optimum condition, which depends on the electronic properties of the surface, the cation exchange capacity of clay, and the affinity of metal polyoxocations to enter the intercalating region [ 80 , 144 ]. Figure 9 presents the effect of the metal:clay ratio on the d 001 of pillared clays, indicating the optimum conditions.…”

“…The band gap energies of SnO 2 -pillared montmorillonite are within the range of 2.49–3.18 eV, depending on the Sn content, and are lower than that of bulk SnO 2 (3.6 eV). Oxide formation in the interlayer region is not as simple as that in the bulk form; therefore, the defects in the crystalline system cause changes in the electronic structure of SnO 2 [ 80 ].…”

“… TEM images of SnO 2 /montmorillonite at Sn/montmorillonite ratios of ( a ) 2.5 and ( b ) 10.0 mmol/10 g. Adapted from Ref. [ 80 ] with permission from the Elsevier B.V., 2021. …”

Current perspective in metal oxide based photocatalysts for virus disinfection: A review

“…( Teymoorian et al, 2021 ; Hasani et al, 2021 ). Advanced oxidation processes (AOPs) are highly advanced technology that generates oxidative and reductive agents like hydroxyl radicles to treat toxic pathogens ( Nasir et al, 2021 ; Kokkinos et al, 2021 ). Generated reactive radicles directly and effectively deteriorate the viruses.…”