Comparing PEROXONE and Ozone for Controlling Taste and Odor Compounds, Disinfection By‐products, and Microorganisms

The Metropolitan Water District of Southern California is evaluating the hydrogen peroxide‐ozone (PEROXONE) advanced oxidation process (followed by secondary disinfection with chloramines) for removal of taste and odor compounds, control of disinfection byproducts (DBPs), and inactivation of microorganisms. This article reports the results of pilot‐scale testing designed to optimize the H 2 O 2 :O 3 ratio and to compare ozone and PEROXONE at different contact times. The tests described represent one phase of a five‐phase PEROXONE pilot‐scale study for treating water from the California State Water Project and from the Colorado River. Results to date indicate that the PEROXONE process requires a significantly lower applied ozone dosage to oxidize 2‐methylisobomeol and geosmin as compared with ozone alone. The levels of DBPs formed when ozone or PEROXONE is used (followed by chloramines) are low, and PEROXONE (at H 2 O 2 :O 3 ratios of ≤0.3) is comparable with ozone for the inactivation of microorganisms.