Updated: 17 October 2013 CEE697K Lecture #10 1 Print version CEE 697K ENVIRONMENTAL REACTION KINETICS Lecture #10 Special Topics: DCP in Water Primary Literature (e.g., Guthrie & Cossar, 1986) Introduction David A. Reckhow
Guthrie 2 J. Peter Guthrie B.Sc. Department of Chemistry Univ. Western Ontario Western University, London, Ontario, Canada, N6A 5B7 PhD Chemistry, 1968 Harvard University DECARBOXYLATION AND ENAMINE FORMATION: MODEL SYSTEMS FOR ACETOACETATE DECARBOXYLASE By James Peter Guthrie Princeton Univ. 1970, Faculty, Western Guthrie, J. P. and J. Cossar (1986). "The University Chlorination of Acetone - A Complete Kinetic Analysis." Canadian Journal of Chemistry-Revue Canadienne De Chimie 64(6): 1250-1266. CEE697K Lecture #10 David A. Reckhow
Mechanisms: Haloform Reaction 3 Chlorine + acetone Morris & Baum, 1978 Brezonik, 1994 Pg 240-241 CEE690K Lecture #09 David A. Reckhow
Haloform reaction: initial step 4 Three potential pathways to enolate Reaction with water (K O ), hydroxide (K OH ), and proton (K H ) k f =K O +K OH [OH - ]+K H [H + ] For acetone, the OH pathway dominates above pH 5.5 + − k [ H ][ A ] = = f What is k r ? K a k [ HA ] r David A. Reckhow CEE690K Lecture #09
Guthrie & Cossar Pathway 5 Scheme 1 CEE697K Lecture #10 David A. Reckhow
Hydrolysis of 1,1-DCP 6 a The many forms of 1,1-DCP The product CEE697K Lecture #10 David A. Reckhow
DCP equilibria I 7 Bell K’s 1.2 H+ alpha E 1.0 alpha Q alpha L alpha 5 0.8 Alpha 0.6 0.4 0.2 0.0 0 2 4 6 8 10 12 14 CEE697K Lecture #10 David A. Reckhow pH
DCP equilibria II 8 Bell K’s 1e+1 1e+0 1e-1 1e-2 1e-3 Alpha 1e-4 1e-5 H+ alpha E 1e-6 alpha Q alpha L 1e-7 alpha 5 1e-8 0 2 4 6 8 10 12 14 CEE697K Lecture #10 David A. Reckhow pH
DCP equilibria III 9 Guthrie K’s 1.2 1.0 0.8 H+ alpha E alpha Q Alpha 0.6 alpha L alpha 5 0.4 0.2 0.0 0 2 4 6 8 10 12 14 CEE697K Lecture #10 David A. Reckhow pH
DCP equilibria IV 10 Guthrie K’s 1e+1 1e+0 1e-1 1e-2 1e-3 Alpha 1e-4 1e-5 H+ alpha E 1e-6 alpha Q alpha L 1e-7 alpha 5 1e-8 0 2 4 6 8 10 12 14 CEE697K Lecture #10 David A. Reckhow pH
Loss of intermediates in lab water 11 21C, ultrapure water (Nikolaou et al., 2001) CEE690K Lecture #09 David A. Reckhow
12 chlorine CEE697K Lecture #10 David A. Reckhow
13 a CEE697K Lecture #10 David A. Reckhow
Model 14 Guthrie model for 1,1-DCP degradation 1000 Chlorine Hydrolysis 100 10 Half-Life (hrs) 1 0.1 0.01 0.001 0.0001 4 5 6 7 8 9 10 11 12 13 14 CEE697K Lecture #10 David A. Reckhow pH
LFER Analysis 15 Baiyang Chen analysis pH 7-7.5 20-25C Predicted hydrolysis rate constant for 1,1- DCP is 10 -1.66 hr -1 Half-life of 31.7 hr 6.1 x 10 -6 sec -1 (Chen, 2011). Data point estimated from Nikolaou et al., 2001 Chen, B. Y. "Hydrolytic Stabilities of Halogenated Disinfection Byproducts: Review and Rate Constant Quantitative Structure- Property Relationship Analysis." Environmental CEE697K Lecture #10 Engineering Science 28(6): 385-394. David A. Reckhow
Comparison with Chen 2001 16 Guthrie model for 1,1-DCP degradation 1000 Chen, 2011 Chlorine Hydrolysis 100 10 Half-Life (hrs) 1 0.1 0.01 0.001 0.0001 4 5 6 7 8 9 10 11 12 13 14 CEE697K Lecture #10 David A. Reckhow pH
Loss in water heaters 17 Liu et al., 3.0 0.6 a No heating b 6 hrs incubation+heating 2.5 0.5 24 hrs incubation+heating 2013 48 hrs incubation+heating 72 hrs incubation+heating 2.0 0.4 1,1-DCP ( g/L) 96 hrs incubation+heating CP ( g/L) In review 1.5 0.3 No heating 1.0 0.2 6 hrs incubation+heating 24 hrs incubation+heating 48 hrs incubation+heating 0.5 0.1 72 hrs incubation+heating 96 hrs incubation+heating 0.0 0.0 0 20 40 60 80 100 120 0 20 40 60 80 100 120 Reaction Time (hr) Reaction Time (hr) 8.0 2.5 c d No heating No heating 6 hrs incubation+heating 6 hrs incubation+heating 24 hrs incubation+heating 2.0 24 hrs incubation+heating 6.0 48 hrs incubation+heating 48 hrs incubation+heating 72 hrs incubation+heating 72 hrs incubation+heating 96 hrs incubation+heating DCAN ( g/L) 1.5 96 hrs incubation+heating TCP ( g/L) 4.0 1.0 2.0 0.5 0.0 0.0 CEE690K Lecture #09 David A. Reckhow 0 20 40 60 80 100 120 0 20 40 60 80 100 120 Reaction Time (hr) Reaction Time (hr)
Profile of 1,1-DCP in Water Systems 18 1,1-Dichloropropanone concentrations compared to the corresponding TTHM concentration for all samples 8.0 6.0 San Francisco Jan(Cl 2 /NH 4 Cl) Charleston(ClO 2 / NH 4 Cl) San Francisco Apr (Cl 2 /NH 4 Cl) 4.0 1,1-dichloropropanone ( g/L) Ann Arbor(O 3 /NH 4 Cl) East Bay( Cl 2 /NH 4 Cl) 3.5 Cincinnati(Cl 2 ) 3.0 Minneapolis (NH 4 Cl/NH 4 Cl) Monroe(O 3 /Cl 2 ) 2.5 Wyoming( Cl 2 /Cl 2 ) Pinellas County(Cl 2 /Cl 2 ) 2.0 Pinellas County(Cl 2 /NH 4 Cl) 1.5 Knoxville(ClO 2 /Cl 2 ) 1.0 0.5 0.0 0 20 40 60 80 100 120 140 CEE697K Lecture #10 David A. Reckhow Chloroform ( g/L)
19 1,1-Dichloropropanone concentrations compared to the corresponding TTHM concentration for all samples: focus on free chlorine plants 1.0 San Francisco Jan(Cl 2 /NH 4 Cl) Charleston(ClO 2 / NH 4 Cl) San Francisco Apr (Cl 2 /NH 4 Cl) 0.8 1,1-dichloropropanone ( g/L) Ann Arbor(O 3 /NH 4 Cl) East Bay( Cl 2 /NH 4 Cl) Cincinnati(Cl 2 ) 0.6 Pinellas County Minneapolis (NH 4 Cl/NH 4 Cl) Monroe Monroe(O 3 /Cl 2 ) Wyoming( Cl 2 /Cl 2 ) Cincinnati Pinellas County(Cl 2 /Cl 2 ) 0.4 Pinellas County(Cl 2 /NH 4 Cl) Knoxville(ClO 2 /Cl 2 ) 0.2 Wyoming 0.0 0 20 40 60 80 100 120 CEE697K Lecture #10 David A. Reckhow Chloroform ( g/L)
Profile of TCP in water systems 20 1,1,1-Trichloropropanone concentrations compared to the corresponding TTHM concentration for all samples 5 San Francisco Jan(Cl 2 /NH 4 Cl) Charleston(ClO 2 / NH 4 Cl) San Francisco Apr (Cl 2 /NH 4 Cl) 1,1,1- trichloropropanone ( g/L) Monroe 4 Ann Arbor(O 3 /NH 4 Cl) East Bay( Cl 2 /NH 4 Cl) Cincinnati(Cl 2 ) 3 Minneapolis (NH 4 Cl/NH 4 Cl) Monroe(O 3 /Cl 2 ) Wyoming( Cl 2 /Cl 2 ) Pinellas County(Cl 2 /Cl 2 ) 2 Pinellas Co. Pinellas County(Cl 2 /NH 4 Cl) Knoxville Knoxville(ClO 2 /Cl 2 ) 1 0 0 20 40 60 80 100 120 140 CEE690K Lecture #09 Chloroform ( g/L) David A. Reckhow
Lab 2 21 15 Oct 2013 experiment 0.3 Absorbance at 292 nm absinf = 0.012 0.2 0.1 0.0 0 100 200 300 Reaction Time (sec) CEE697K Lecture #10 Time (s) vs Abs David A. Reckhow
Lab 2 22 1 st order plot -1 absinf = 0.012 b[1]-0.0128851211 -2 K = 46 hr -1 Ln (Abs-Abs -3 -4 -5 -6 0 100 200 300 Reaction Time (sec) Time (s) vs ln abs-absinf CEE697K Lecture #10 David A. Reckhow Plot 1 Regr
Lab 2 23 2 nd order plot 300 250 200 1/(Abs-Abs 150 100 50 0 0 100 200 300 Reaction Time (sec) CEE697K Lecture #10 Time (s) vs 1/(abs-absinf) David A. Reckhow Plot 1 Regr
24 Guthrie model 1000 Chlorine Hydrolysis 100 10 Half-Life (hrs) 1 0.1 0.01 0.001 0.0001 4 5 6 7 8 9 10 11 12 13 14 CEE697K Lecture #10 David A. Reckhow pH
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