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Controlling bromate Formation
Author(s) -
Galey Catherine,
MaryDilé Veronique,
Gatel Dominique,
Amy Gary,
Cavard Jacques
Publication year - 2001
Publication title -
journal ‐ american water works association
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.466
H-Index - 74
eISSN - 1551-8833
pISSN - 0003-150X
DOI - 10.1002/j.1551-8833.2001.tb09271.x
Subject(s) - bromate , ozone , chemistry , factorial experiment , fractional factorial design , hydraulic retention time , inorganic chemistry , environmental engineering , effluent , mathematics , environmental science , organic chemistry , bromide , statistics
A pilot‐scale study, based on a fractional factorial experimental design, was performed to evaluate the indirect impact of preozonation (0‐1.5 mg/L) and/or the addition of powdered activated carbon (PAC) (0‐20 mg/L), and the direct impact of intermediate ozone (O 3 ) dose (1.2‐3.0 mg/L), pH (6.0‐7.5), and hydraulic residence time (HRT—12‐18 min) on bromate (BrO 3 ‐ ) formation. Under the conditions of this study, neither preozonation nor PAC addition had a significant impact on BrO 3 ‐ formation observed at the outlet of the pilot contactor. The most influential parameter was pH, followed by intermediate O 3 dose. A cross‐effect (interaction between pH and intermediate O 3 dose) was also statistically significant. Consequently, the impact of pH depression on BrO 3 ‐ formation was shown to be O 3 ‐dose‐dependent. During these experiments, the BrO 3 ‐ standard of 10 μg/L was achieved with O 3 doses of < 1.6 mg/L and a pH of < 6.3. These conditions were consistent with 2‐log—but not 3‐log—inactivation of Cryptosporidium.