Sunlight-mediated inactivation of health-relevant microorganisms in water : a review of mechanisms and modeling approaches

Health-relevant microorganisms present in natural surface waters and engineered treatment systems that are exposed to sunlight can be inactivated by a complex set of interacting mechanisms. The net impact of sunlight depends on the solar spectral irradiance, the susceptibility of the specific microorganism to each mechanism, and the water quality; inactivation rates can vary by orders of magnitude depending on the organism and environmental conditions. Natural organic matter (NOM) has a large influence, as it can attenuate radiation and thus decrease inactivation by endogenous mechanisms. Simultaneously NOM sensitizes the formation of reactive intermediates that can damage microorganisms via exogenous mechanisms. To accurately predict inactivation and design engineered systems that enhance solar inactivation, it is necessary to model these processes, although some details are not yet sufficiently well understood. In this critical review, we summarize the photo-physics, -chemistry, and -biology that underpin sunlight-mediated inactivation, as well as the targets of damage and cellular responses to sunlight exposure. Viruses that are not susceptible to exogenous inactivation are only inactivated if UVB wavelengths (280-320 nm) are present, such as in very clear, open waters or in containers that are transparent to UVB. Bacteria are susceptible to slightly longer wavelengths. Some viruses and bacteria (especially Gram-positive) are susceptible to exogenous inactivation, which can be initiated by visible as well as UV wavelengths. We review approaches to model sunlight-mediated inactivation and illustrate how the environmental conditions can dramatically shift the inactivation rate of organisms. The implications of this mechanistic understanding of solar inactivation are discussed for a range of applications, including recreational water quality, natural treatment systems, solar disinfection of drinking water (SODIS), and enhanced inactivation via the use of sensitizers and photocatalysts. Finally, priorities for future research are identified that will further our understanding of the key role that sunlight disinfection plays in natural systems and the potential to enhance this process in engineered systems.

Medienart:

E-Artikel

Erscheinungsjahr:

2018

Erschienen:

2018

Enthalten in:

Zur Gesamtaufnahme - volume:20

Enthalten in:

Environmental science. Processes & impacts - 20(2018), 8 vom: 16. Aug., Seite 1089-1122

Sprache:

Englisch

Beteiligte Personen:

Nelson, Kara L [VerfasserIn]
Boehm, Alexandria B [VerfasserIn]
Davies-Colley, Robert J [VerfasserIn]
Dodd, Michael C [VerfasserIn]
Kohn, Tamar [VerfasserIn]
Linden, Karl G [VerfasserIn]
Liu, Yuanyuan [VerfasserIn]
Maraccini, Peter A [VerfasserIn]
McNeill, Kristopher [VerfasserIn]
Mitch, William A [VerfasserIn]
Nguyen, Thanh H [VerfasserIn]
Parker, Kimberly M [VerfasserIn]
Rodriguez, Roberto A [VerfasserIn]
Sassoubre, Lauren M [VerfasserIn]
Silverman, Andrea I [VerfasserIn]
Wigginton, Krista R [VerfasserIn]
Zepp, Richard G [VerfasserIn]

Links:

Volltext

Themen:

Journal Article
Review

Anmerkungen:

Date Completed 22.10.2018

Date Revised 09.01.2021

published: Print

Citation Status MEDLINE

doi:

10.1039/c8em00047f

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM286880903