TY - JOUR
T1 - Nanoparticle and Transparent Polymer Coatings Enable UV-C Side-Emission Optical Fibers for Inactivation of Escherichia coli in Water
AU - Lanzarini-Lopes, Mariana
AU - Cruz, Brandon
AU - GARCIA SEGURA, Sergio
AU - Alum, Absar
AU - Abbaszadegan, Morteza
AU - Westerhoff, Paul
N1 - Publisher Copyright:
Copyright © 2019 American Chemical Society.
PY - 2019/9/17
Y1 - 2019/9/17
N2 - Pathogenic bacteria pose a health threat and operational challenge in drinking water. UV-C light-emitting diodes (UV-C LEDs) are becoming a competitive disinfection technology but are limited by their small irradiation area. Side-emitting optical fibers (SEOFs) can serve as a UV-C LED light delivery technology for reactors or tubing. Modifying the surfaces of conventional optical fibers with scattering centers allows for side emission of 265 nm radiation from an LED for microbial inactivation in water. Solid-material absorbance and flux measurements differentiated light absorption from scattering for all materials. Silica spheres >200 nm in diameter achieved higher scattering than smaller silica. A critical discovery was that treating the silica-coated optical fiber in a solution of high ionic strength increased UV-C side emission by greater than 6-fold. Additionally, the cladding polymer Cytop had negligible absorbance at 265 nm wavelength. A scalable four-step treatment process was developed to fabricate the novel SEOF. Attached to a 265 nm LED, the side-emitting optical fiber achieved 2.9 log inactivation of Escherichia coli at a delivery dose of 15 mJ/cm2. The results illustrate proof of concept that UV-C SEOFs can inactivate E. coli and should be further explored for delivering LED light into water.
AB - Pathogenic bacteria pose a health threat and operational challenge in drinking water. UV-C light-emitting diodes (UV-C LEDs) are becoming a competitive disinfection technology but are limited by their small irradiation area. Side-emitting optical fibers (SEOFs) can serve as a UV-C LED light delivery technology for reactors or tubing. Modifying the surfaces of conventional optical fibers with scattering centers allows for side emission of 265 nm radiation from an LED for microbial inactivation in water. Solid-material absorbance and flux measurements differentiated light absorption from scattering for all materials. Silica spheres >200 nm in diameter achieved higher scattering than smaller silica. A critical discovery was that treating the silica-coated optical fiber in a solution of high ionic strength increased UV-C side emission by greater than 6-fold. Additionally, the cladding polymer Cytop had negligible absorbance at 265 nm wavelength. A scalable four-step treatment process was developed to fabricate the novel SEOF. Attached to a 265 nm LED, the side-emitting optical fiber achieved 2.9 log inactivation of Escherichia coli at a delivery dose of 15 mJ/cm2. The results illustrate proof of concept that UV-C SEOFs can inactivate E. coli and should be further explored for delivering LED light into water.
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U2 - 10.1021/acs.est.9b01958
DO - 10.1021/acs.est.9b01958
M3 - Article
C2 - 31397559
AN - SCOPUS:85072350665
SN - 0013-936X
VL - 53
SP - 10880
EP - 10887
JO - Environmental Science and Technology
JF - Environmental Science and Technology
IS - 18
ER -