Evaluation of bromine substitution factors of DBPs during chlorination and chloramination.
Bromine substitution factor (BSF) was used to quantify the effects of disinfectant dose, reaction time, pH, and temperature on the bromine substitution of disinfection byproducts (DBPs) during chlorination and chloramination. The BSF is defined as the ratio of the bromine incorporated into a given class of DBPs to the total concentration of chlorine and bromine in that class. Four classes of DBPs were evaluated: trihalomethanes (THMs), dihaloacetonitriles (DHANs), dihaloacetic acids (DHAAs) and trihaloacetic acids (THAAs). The results showed that the BSFs of the four classes of DBPs generally decreased with increasing reaction time and temperature during chlorination at neutral pH. The BSFs peaked at a low chlorine dose (1 mg/L) and decreased when the chlorine dose further increased. The BSFs of chlorination DBPs at neutral pH are in the order of DHAN > THM & DHAA > THAA. DHAAs formed by chloramines exhibited distinctly different bromine substitution patterns compared to chlorination DHAAs. Brominated DBP formation was generally less affected by the pH change compared to chlorinated DBP formation.
Jones Edmunds & Associates, Inc, 730 NE Waldo Road, Gainesville, FL 32641, United States. ghua@jonesedmunds.com
Guanghui
G
Hua
David A
DA
Reckhow
D019342:Acetic Acid / Q000737:chemistry; D000097:Acetonitriles / Q000737:chemistry; D001966:Bromine / Q000737:chemistry*; D002700:Chloramines / Q000737:chemistry*; D004203:Disinfection / Q000379:methods*; D060766:Drinking Water / Q000737:chemistry; D054879:Halogenation; D006846:Hydrocarbons, Halogenated / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D013696:Temperature; D013997:Time Factors; D022882:Trihalomethanes / Q000737:chemistry; D014881:Water Supply / Q000032:analysis
D000097:Acetonitriles; D002700:Chloramines; D060766:Drinking Water; D006846:Hydrocarbons, Halogenated; D022882:Trihalomethanes; D019342:Acetic Acid; D001966:Bromine