Temperature Dependence of the Reaction between the Hydroxyl Radical and Organic Matter
The temperature-dependent bimolecular rate constants for the reaction of the hydroxyl radical (HO*)with organic matter (OM) (koM-HO*) have been measured for three natural organic matter (NOM) isolates and three bulk effluent organic matter (EfOM) samples using electron pulse radiolysis and thiocyanate competition kinetics.The range of values for the room temperature kOM-HO,was 1.21-9.37 × 108 Mc-1 s-1,with NOM isolates generally reacting slower than EfOM samples.The NOM isolates had an average apparent activation energy of 19.8 kJ mol-1,while the EfOM samples had an average value slightly lower (14.3 kJ mol-1),although one NOM isolate (Elliot Soil Humic Acid,29.9 kJ mo1-1) was a factor of 2 times greater than other samples studied.These apparent activation energies are the first determined for OM and HO·,and the Arrhenius plots obtained for NOM isolates (lowest Ra>0.993) suggest that no significant structural changes are occurring over the temperature range 8-41 ℃.In contrast,the greater scatter (lowest R2>0.903) observed for the EfOM samples suggests that some structural changes may be occurring.These results provide a deeper fundamental understanding of the reaction between OM and HO9 and will be useful in quantifying HO.reactions in natural and engineered systems.
Hydroxyl radical Organic matter Reactivity Temperature dependence
G.McKay M.M.Dong J.Kleinman S.P.Mezyk F.L.Rosario-Ortiz
Department of Chemistry and Biochemistry,California State University Long Beach,Long Beach,CA 92617 Department of Environmental Engineering,University of Colorado Boulder,Boulder,CO 80309
国际会议
the 16th Meeting of the International Humic Substances Society (第十六届国际腐殖物质学会大会(IHSS 16))
杭州
英文
184-186
2012-09-09（万方平台首次上网日期，不代表论文的发表时间）