Characterizing reactive oxygen generation and bacterial inactivation by a zerovalent iron-fullerene nano-composite device at neutral pH under UV-A illumination

TitleCharacterizing reactive oxygen generation and bacterial inactivation by a zerovalent iron-fullerene nano-composite device at neutral pH under UV-A illumination
Publication TypeJournal Article
Year of Publication2015
AuthorsErdim, E, Badireddy, AR, Wiesner, MR
JournalJournal of Hazardous Materials
Volume283
Pagination80 - 88
Date Published02/2015
ISSN03043894
Abstract

A nano-composite device composed of nano-scale zerovalent iron (ZVI) and C60 fullerene aggregates (ZVI/nC60) was produced via a rapid nucleation method. The device was conceived to deliver reactive oxygen species (ROS) generated by photosensitization and/or electron transfer to targeted contaminants, including waterborne pathogens under neutral pH conditions. Certain variations of the nano-composite were fabricated differing in the amounts of (1) ZVI (0.1 mM and 2 mM) but not nC60 (2.5 mg-C/L), and (2) nC60 (0–25 mg-C/L) but not ZVI (0.1 mM). The generation of ROS by the ZVI/nC60 nano-composites and ZVI nanoparticles was quantified using organic probe compounds. 0.1 mM ZVI/2.5 mg-C/L C60 generated 3.74-fold higher O2radical dot− concentration and also resulted in an additional 2-log inactivation of Pseudomonas aeruginosa when compared to 0.1 mM ZVI (3-log inactivation). 2 mM ZVI/2.5 mg-C/L nC60 showed negligible improvement over 2 mM ZVI in terms of O2radical dot− generation or inactivation. Further, incremental amounts of nC60 in the range of 0–25 mg-C/L in 0.1 mM ZVI/nC60 led to increased O2radical dot− concentration, independent of UV-A. This study demonstrates that ZVI/nC60 device delivers (1) enhanced O2radical dot− with nC60 as a mediator for electron transfer, and (2) 1O2 (only under UV-A illumination) at neutral pH conditions.

DOI10.1016/j.jhazmat.2014.08.049
Short TitleJournal of Hazardous Materials