TY - JOUR
T1 - A comparison of pilot-scale photocatalysis and enhanced coagulation for disinfection byproduct mitigation
AU - Gerrity, Daniel
AU - Mayer, Brooke
AU - Ryu, Hodon
AU - Crittenden, John
AU - Abbaszadegan, Morteza
N1 - Funding Information:
This research was supported by the National Science Foundation (NSF) Water Quality Center at Arizona State University. This work was performed while Daniel Gerrity was on appointment as a United States Department of Homeland Security (DHS) Fellow under the DHS Scholarship and Fellowship Program. All opinions expressed in this paper are the authors' and do not necessarily reflect the policies and views of NSF, DHS, or Purifics ® .
PY - 2009/4
Y1 - 2009/4
N2 - This study evaluated pilot-scale photocatalysis and enhanced coagulation for their ability to remove or destroy disinfection byproduct (DBP) precursors, trihalomethane (THM) formation potential (FP), and THMs in two Arizona surface waters. Limited photocatalysis (<5 kWh/m3) achieved reductions in most of the DBP precursor parameters (e.g., DOC, UV254, and bromide) but led to increased chlorine demand and THMFP. In contrast, enhanced coagulation achieved reductions in the DBP precursors and THMFP. Extended photocatalysis (<320 kWh/m3) decreased THMFP once the energy consumption exceeded 20 kWh/m3. The photocatalytic energy requirements for THM destruction were considerably lower (EEO = 20-60 kWh/m3) than when focusing on precursor destruction and THMFP. However, rechlorination increased the total THM (TTHM) concentration well beyond the raw value, thereby negating the energy benefits of this application. Enhanced coagulation achieved consistent 20-30% removals of preformed THMs. Outstanding issues need to be addressed before TiO2 photocatalysis is considered feasible for DBP mitigation; traditional strategies, including enhanced coagulation, may be more appropriate.
AB - This study evaluated pilot-scale photocatalysis and enhanced coagulation for their ability to remove or destroy disinfection byproduct (DBP) precursors, trihalomethane (THM) formation potential (FP), and THMs in two Arizona surface waters. Limited photocatalysis (<5 kWh/m3) achieved reductions in most of the DBP precursor parameters (e.g., DOC, UV254, and bromide) but led to increased chlorine demand and THMFP. In contrast, enhanced coagulation achieved reductions in the DBP precursors and THMFP. Extended photocatalysis (<320 kWh/m3) decreased THMFP once the energy consumption exceeded 20 kWh/m3. The photocatalytic energy requirements for THM destruction were considerably lower (EEO = 20-60 kWh/m3) than when focusing on precursor destruction and THMFP. However, rechlorination increased the total THM (TTHM) concentration well beyond the raw value, thereby negating the energy benefits of this application. Enhanced coagulation achieved consistent 20-30% removals of preformed THMs. Outstanding issues need to be addressed before TiO2 photocatalysis is considered feasible for DBP mitigation; traditional strategies, including enhanced coagulation, may be more appropriate.
KW - Advanced oxidation
KW - Disinfection byproduct
KW - Enhanced coagulation
KW - Photocatalysis
KW - Trihalomethane
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U2 - 10.1016/j.watres.2009.01.010
DO - 10.1016/j.watres.2009.01.010
M3 - Article
C2 - 19232668
AN - SCOPUS:62649174629
SN - 0043-1354
VL - 43
SP - 1597
EP - 1610
JO - Water Research
JF - Water Research
IS - 6
ER -