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Title: Chlorine utilization during trihalomethane formation in the presence of ammonia and bromide

The chlorination of humic substances in the presence of ammonia and bromide and the resultant formation of trihalomethanes (THM) are described. The presence of ammonia substantially reduced but did not eliminate THM production during the chlorination of waters containing humic substances. The presence of bromide ion in waters containing humic substances leads to increased THM formation, both in the presence and in the absence of ammonia. In waters containing ammonia, bromide, and humic substances, brominated haloforms can form upon chlorination. Brominated species comprise a larger portion of the total THMs at higher chlorine doses within the free chlorine region of the breakpoint curve than at lower dose in the subbreakpoint region. Although the THM formation reaction is slow and may not be complete even after 1 week of reaction time, the initial rate of formation is competitive with the relatively rapid reactions of bromide oxidation and chloramine formation. After free chlorine is converted to chloramines, THM production should theoretically cease. THMs will form in parallel with chloramine formation. This behavior has important implications for water utilities that use a raw water source containing low but significant levels of ammonia such as the Biscayne Aquifer, or are considering chloramine disinfection asmore » a THM control strategy.« less
Authors:
; ; ;
Publication Date:
OSTI Identifier:
5371240
Resource Type:
Journal Article
Resource Relation:
Journal Name: Environ. Sci. Technol.; (United States); Journal Volume: 18:10
Research Org:
Univ. of Arizona, Tucson
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; HUMIC ACIDS; WATER CHEMISTRY; ORGANIC HALOGEN COMPOUNDS; SYNTHESIS; AMMONIA; BROMIDES; CHLORINATION; POLLUTION SOURCES; WATER POLLUTION; WATER SUPPLY; BROMINE COMPOUNDS; CHEMICAL REACTIONS; CHEMISTRY; HALIDES; HALOGEN COMPOUNDS; HALOGENATION; HYDRIDES; HYDROGEN COMPOUNDS; NITROGEN COMPOUNDS; NITROGEN HYDRIDES; ORGANIC ACIDS; ORGANIC COMPOUNDS; POLLUTION 520200* -- Environment, Aquatic-- Chemicals Monitoring & Transport-- (-1989)