Disinfection and Self-Sensitized Degradation of Natural Organic Matter (NOM) by TiO2 Photocatalysis with Visible light
Date
2013-09-04
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Abstract
The reaction of natural organic matter (NOM) with chlorine results in formation of disinfection by products (DBPs), known carcinogens. Fulvic acid (FA), a key component of NOM is likely a precursor to DBPs. Photocatalytic advanced oxidation using TiO2 is efficient under UV irradiation and known to degrade humics with reduction of DBPs. However, TiO2 may be dye “sensitized” for visible light, where the dye excited state transfers an electron to TiO2 conduction band. NOM adsorbs on the surface of TiO2 and sensitizes (“self-sensitization”). NOM undergoes an initial oxidative step upon visible light absorption and transfers an electron to the TiO2 conduction band. Oxygen captures the electron, forming superoxide which can aid in degradation of NOM. Model studies with Suwannee river fulvic acid are reported and then extended to “real water samples” from Southern Alberta. The humic model shows different degradation behavior from ‘real’ samples. In addition to reduction of NOM by “self-sensitization”, the active species also achieve reduction of Total coliform and Escherichia coli. The objective of this research is to treat NOM and simultaneously enhance disinfection.
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Keywords
Analytical, Inorganic
Citation
Chamoli, U. (2013). Disinfection and Self-Sensitized Degradation of Natural Organic Matter (NOM) by TiO2 Photocatalysis with Visible light (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/25720