Development of a Five-Chemical-Probe Method to Determine Multiple Radicals Simultaneously in Hydroxyl and Sulfate Radical-Mediated Advanced Oxidation Processes.
Environ Sci Technol
; 58(12): 5616-5626, 2024 Mar 26.
Article
in En
| MEDLINE
| ID: mdl-38471100
ABSTRACT
Advanced oxidation processes (AOPs), such as hydroxyl radical (HOâ¢)- and sulfate radical (SO4â¢-)-mediated oxidation, are attractive technologies used in water and wastewater treatments. To evaluate the treatment efficiencies of AOPs, monitoring the primary radicals (HO⢠and SO4â¢-) as well as the secondary radicals generated from the reaction of HOâ¢/SO4â¢- with water matrices is necessary. Therefore, we developed a novel chemical probe method to examine five key radicals simultaneously, including HOâ¢, SO4â¢-, Clâ¢, Cl2â¢-, and CO3â¢-. Five probes, including nitrobenzene, para-chlorobenzoic acid, benzoic acid, 2,4,6-trimethylbenzoic acid, and 2,4,6-trimethylphenol, were selected in this study. Their bimolecular reaction rate constants with diverse radicals were first calibrated under the same conditions to minimize systematic errors. Three typical AOPs (UV/H2O2, UV/S2O82-, and UV/HSO5-) were tested to obtain the radical steady-state concentrations. The effects of dissolved organic matter, Br-, and the probe concentration were inspected. Our results suggest that the five-probe method can accurately measure radicals in the HOâ¢- and SO4â¢--mediated AOPs when the concentration of Br- and DOM are less than 4.0 µM and 15 mgC L-1, respectively. Overall, the five-probe method is a practical and easily accessible method to determine multiple radicals simultaneously.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Sulfates
/
Water Pollutants, Chemical
/
Water Purification
Language:
En
Journal:
Environ Sci Technol
Year:
2024
Document type:
Article