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Addition of Hydrogen Peroxide to Groundwater with Natural Iron Induces Water Disinfection by Photo‐Fenton at Circumneutral pH and other Photochemical Events
Author(s) -
GutiérrezZapata Héctor Mario,
AlvearDaza John Jairo,
RengifoHerrera Julián Andrés,
Sanabria Janeth
Publication year - 2017
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/php.12779
Subject(s) - hydrogen peroxide , chemistry , groundwater , environmental chemistry , photochemistry , geology , organic chemistry , geotechnical engineering
Samples of natural groundwater (with low turbidity, neutral pH and 0.3 mg L −1 iron concentration) inoculated with Escherichia coli K‐12 were exposed to simulated solar light both in the presence and in the absence 10 mg L −1 of H 2 O 2. Results demonstrated that the viability of E. coli (by DVC–FISH) was grounded to zero after 360 min of irradiation. This abatement could be caused by the oxidative stress induced by · OH radicals or another photo‐induced reactive oxygen species. Two 2 3 factorial experimental designs enabled the evaluation of the effects of chemical factors on the inactivation of E. coli . The first experimental design considered the pH , iron and H 2 O 2 , while the second evaluated the ions fluoride, carbonate and phosphate found in groundwater. pH was found to play a key role in the inactivation of E. coli . The best reduction in viability was obtained at the lower pH (6.75), while a nonsignificant effect was observed when iron or H 2 O 2 concentrations were raised. At higher concentrations, anions, such as carbonate and phosphate, negatively affected the E. coli abatement. However, a higher concentration of fluoride accelerated it. In all experiments, the pH was observed to rise to values higher than 8.0 units after 360 min of treatment.