title: Effect of pre-ozonation on the formation and speciation of DBPs.
abstract: The objective of this study was to quantitatively evaluate the effect of pre-ozonation on the formation and speciation of disinfection byproducts (DBPs) from subsequent chlorination and chloramination. Laboratory experiments were conducted on six diverse natural waters with low to medium bromide concentrations. Four groups of DBPs were investigated in this study: trihalomethanes (THMs), trihaloacetic acids (THAAs), dihaloacetic acids (DHAAs), and dihaloacetonitriles (DHANs). The results showed that the relative destructions of chlorination DBP precursors by ozone generally follow the order of DHANs > THMs & THAAs > DHAAs. Pre-ozonation substantially increased the DHAA precursors in the waters with low specific ultraviolet absorbance values. Pre-ozonation shifted the formation of DBPs to more brominated species. The bromine substitution factors (BSF) of different chlorination DBPs typically increased by 1-8 percentage points after ozonation. Pre-ozonation reduced the yields of chloramination DHAAs and THMs and increased the BSFs of chloramination DHAAs by 1-6 percentage points.
authors.affiliation: Department of Civil and Environmental Engineering, South Dakota State University, Brookings, SD 57007, USA. guanghui.hua@sdstate.edu
authors.forename: Guanghui
authors.initials: G
authors.lastname: Hua
authors.forename: David A
authors.initials: DA
authors.lastname: Reckhow
mesh_terms: D019342:Acetic Acid / Q000032:analysis; D000097:Acetonitriles / Q000032:analysis; D001966:Bromine / Q000032:analysis; D002700:Chloramines / Q000032:analysis; D004203:Disinfection; D060766:Drinking Water / Q000737:chemistry; D054879:Halogenation; D006863:Hydrogen-Ion Concentration; D010126:Ozone / Q000737:chemistry*; D013696:Temperature; D022882:Trihalomethanes / Q000032:analysis; D014466:Ultraviolet Rays; D018508:Water Purification
chemical_list: D000097:Acetonitriles; D002700:Chloramines; D060766:Drinking Water; D022882:Trihalomethanes; D010126:Ozone; D019342:Acetic Acid; D001966:Bromine; C032159:acetonitrile
keywords: Bromine substitution factor; Chloramine; Chlorine; Disinfection byproducts; Ozonation