Ozonation of water: kinetics of oxidation of ammonia by ozone and hydroxyl radicals

Journal Article · Sat Dec 31 23:00:00 EST 1977 · Environ. Sci. Technol.; (United States)

DOI:https://doi.org/10.1021/es60137a005· OSTI ID:5120190

Hoigne, J; Bader, H

A laboratory study showed that ozone-initiated oxidation of ammonia in water can result from the direct reaction of ozone with ammonia as well as from the reactions of hydroxyl radicals formed upon ozone decomposition. The direct reaction of ozone predominated at pH < 9, but in the presence of low concentrations of free ammonia, it is a slow reaction. At pH > 9, the hydroxyl ion and radical-catalyzed decomposition of ozone to the reactive hydroxyl radical intermediate determines the kinetics of the ammonia oxidation. The reaction rate constant of hydroxyl radical with ammonia is relatively small. Whenever the hydroxyl radical mechanism is involved, ammonia is easily protected by other solutes which also consume hydroxyl radicals. Even carbonate and bicarbonate ions may act as efficient hydroxyl radical scavengers. Because carbonate and organic solutes affect the lifetime of ozone in water, they consequently shift the pH range in which either the direct ozone or the hydroxyl radical mechanism predominates.

• Research Organization: Swiss Fed. Inst., Water Resources and Water Pollut. Control
• OSTI ID: 5120190
• Journal Information: Environ. Sci. Technol.; (United States), Journal Name: Environ. Sci. Technol.; (United States) Vol. 12:1; ISSN ESTHA
• Country of Publication: United States
• Language: English

Related Subjects

090310* -- Inorganic Hydrogen Compound Fuels-- Properties-- (1976-1989)
10 SYNTHETIC FUELS
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201 -- Chemical &amp; Physicochemical Properties
AMMONIA
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
HYDRIDES
HYDROGEN COMPOUNDS
HYDROXYL RADICALS
KINETICS
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
OXIDATION
OXYGEN COMPOUNDS
OZONE
RADICALS
REACTION KINETICS
WATER