title: Examination of NOM chlorination reactions by conventional and stop-flow differential absorbance spectroscopy.
abstract: Mechanisms of chlorination of natural organic matter (NOM) in surface water (Lake Washington) were explored via differential spectroscopy. Two types of differential spectra (overall and incremental) were generated for this water chlorinated at pH 7 using varying chlorine doses and reaction times. The differential spectra contain two kinetically and spectroscopically distinct components. One of these components is attributable to functional groups that react rapidly with chlorine, while the other reflects transformations of slowly reacting chromophores that arise following the depletion of the fast chromophores. Small concentrations of disinfection byproducts (DBPs), exemplified in this study by dichloroacetic acid and chloral hydrate, were produced during the initial phase of chlorination, when the fast-reacting chromophores were being consumed. Rather, the release of those DBPs was correlated with the breakdown of the slowly reacting chromophores.
authors.affiliation: Department of Civil and Environmental Engineering, University of Washington, Box 352700 Seattle, Washington 98195-2700, USA. korshin@u.washington.edu
authors.forename: Gregory V
authors.initials: GV
authors.lastname: Korshin
authors.forename: Mark M
authors.initials: MM
authors.lastname: Benjamin
authors.forename: Hyun-Shik
authors.initials: HS
authors.lastname: Chang
authors.forename: Hervé
authors.initials: H
authors.lastname: Gallard
mesh_terms: D002713:Chlorine / Q000737:chemistry*; D004202:Disinfectants / Q000737:chemistry; D005618:Fresh Water / Q000737:chemistry*; D009930:Organic Chemicals / Q000737:chemistry*; D013053:Spectrophotometry / Q000379:methods*; D014873:Water Pollutants; D014881:Water Supply
chemical_list: D004202:Disinfectants; D009930:Organic Chemicals; D014873:Water Pollutants; D002713:Chlorine