Disinfection Byproduct Formation Resulting from Settled, Filtered, and Finished Water Treated by Titanium Dioxide Photocatalysis

Authors

Brooke K. Mayer, Marquette UniversityFollow
Erin Daugherty, Arizona State University at the Tempe Campus
Morteza Abbaszadegan, Arizona State University at the Tempe CampusFollow

Document Type

Article

Language

eng

Format of Original

7 p.

Publication Date

12-2014

Publisher

Elsevier

Source Publication

Chemosphere

Source ISSN

0045-6535

Original Item ID

doi: 10.1016/j.chemosphere.2014.05.073

Abstract

This study evaluated strategies targeting disinfection byproduct (DBP) mitigation using TiO₂ photocatalysis with varying influent water quality. A Purifics Photo-CAT Lab reactor was used to assess total trihalomethane (TTHM) and haloacetic acid (HAA) formation as a function of photocatalytic treatment using water from a conventional coagulation/flocculation/sedimentation process, granular activated carbon filtration, and a DBP hot spot in the water distribution system. Regardless of influent water quality, photocatalysis reduced DBP precursors; however, low-energy limited photocatalysis (m⁻³), exacerbated the production of TTHMs and HAA5s beyond initial levels. Accordingly, limited photocatalysis is not a suitable option when TTHMs and HAA5s are a concern, regardless of the level of pretreatment. Limited photocatalysis yields incomplete oxidation, wherein larger, more aromatic, humic organic compounds are broken into smaller molecular weight, less aromatic, and less humic moieties, which have considerable potential to produce DBPs. More complete mineralization of DBP precursors is obtained using extended photocatalysis (80–160 kW h m⁻³), which substantially decreases DBP precursors as well as TTHM and HAA5 concentrations. In order to balance DBP mitigation, energy, and chemical usage, targeted use of TiO₂ photocatalysis is necessary in a water treatment train (e.g., extended photocatalysis at a distribution system hot spot, where the volumetrically high energy requirements may be justifiable).

Comments

Accepted version. Chemosphere, Vol. 117 (December 2014): 72-78. DOI. © 2014 Elsevier. Used with permission.

Recommended Citation

Mayer, Brooke K.; Daugherty, Erin; and Abbaszadegan, Morteza, "Disinfection Byproduct Formation Resulting from Settled, Filtered, and Finished Water Treated by Titanium Dioxide Photocatalysis" (2014). Civil and Environmental Engineering Faculty Research and Publications. 36.
https://epublications.marquette.edu/civengin_fac/36