Premium
Effect of Ozone Dissolution Systems on Ozone Exposure and Bromate Formation
Author(s) -
Wert Eric C.,
Lew Julia,
Rakness Kerwin L.
Publication year - 2017
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 - 10.5942/jawwa.2017.109.0048
Subject(s) - bromate , ozone , dissolution , chemistry , inorganic chemistry , organic chemistry , bromide
Pilot‐scale data were generated to improve operational guidance for fine bubble diffusion (FBD) and sidestream addition (SSA) systems with respect to unaccounted‐for ozone exposure—i.e., concentration times time ( C × T ), and bromate formation during ozone dissolution. In FBD systems, results showed significant ozone dissolution C × T (0.31–2.85 mg‐min/L) and bromate formation (0.8–9.1 µg/L) occurring in the bubble column, which is not included in regulatory compliance C × T calculations. Utilities may consider taking contactors out of service to minimize contact time and corresponding bromate formation in the dissolution zone. In SSA systems, ozone dosages (7.2–18.6 mg/L) were transferred to approximately 20% of the overall plant flow for ~5 s, which produced bromate (2.6–5.7 µg/L). As the contact time exceeded the design guidance in the sidestream flow (>30 s), bromate formation became far more significant (40–140 µg/L). When the sidestream flow is operated with short contact times (~5 s), bromate formation can be minimized.