CEE 697K ENVIRONMENTAL REACTION KINETICS

Introduction David A. Reckhow

CEE697K Lecture #10 1 Updated: 17 October 2013

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Lecture #10 Special Topics: DCP in Water Primary Literature (e.g., Guthrie & Cossar, 1986)

Guthrie

J. Peter Guthrie Department of Chemistry

Western University, London, Ontario, Canada, N6A 5B7

B.Sc. Univ. Western Ontario

PhD Chemistry, 1968 Harvard University DECARBOXYLATION AND ENAMINE

FORMATION: MODEL SYSTEMS FOR ACETOACETATE DECARBOXYLASE By James Peter Guthrie

Princeton Univ. 1970, Faculty, Western

University

David A. Reckhow

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CEE697K Lecture #10

Guthrie, J. P. and J. Cossar (1986). "The Chlorination of Acetone - A Complete Kinetic Analysis." Canadian Journal of Chemistry-Revue Canadienne De Chimie 64(6): 1250-1266.

Mechanisms: Haloform Reaction

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Chlorine + acetone Morris & Baum, 1978 Brezonik, 1994 Pg 240-241

Haloform reaction: initial step

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Three potential pathways to enolate Reaction with water (KO), hydroxide (KOH), and proton (KH) kf=KO+KOH[OH-]+KH[H+] For acetone, the OH pathway dominates above pH 5.5

What is kr? ][]][[

HAAH

kk

Kr

fa

−+

==

Guthrie & Cossar Pathway

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Scheme 1

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a

Hydrolysis of 1,1-DCP

The product

The many forms of 1,1-DCP

DCP equilibria I

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Bell K’s

pH

0 2 4 6 8 10 12 14

Alp

ha

0.0

0.2

0.4

0.6

0.8

1.0

1.2

H+ alpha E alpha Q alpha L alpha 5

DCP equilibria II

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Bell K’s

pH

0 2 4 6 8 10 12 14

Alp

ha

1e-8

1e-7

1e-6

1e-5

1e-4

1e-3

1e-2

1e-1

1e+0

1e+1

H+ alpha E alpha Q alpha L alpha 5

DCP equilibria III

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Guthrie K’s

pH

0 2 4 6 8 10 12 14

Alp

ha

0.0

0.2

0.4

0.6

0.8

1.0

1.2

H+ alpha E alpha Q alpha L alpha 5

DCP equilibria IV

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Guthrie K’s

pH

0 2 4 6 8 10 12 14

Alp

ha

1e-8

1e-7

1e-6

1e-5

1e-4

1e-3

1e-2

1e-1

1e+0

1e+1

H+ alpha E alpha Q alpha L alpha 5

Loss of intermediates in lab water

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21C, ultrapure water (Nikolaou et al.,

2001)

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chlorine

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a

Model

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Guthrie model for 1,1-DCP degradation

pH

4 5 6 7 8 9 10 11 12 13 14

Hal

f-Life

(hrs

)

0.0001

0.001

0.01

0.1

1

10

100

1000

ChlorineHydrolysis

LFER Analysis

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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 Engineering Science 28(6): 385-394.

Comparison with Chen 2001

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Guthrie model for 1,1-DCP degradation

pH

4 5 6 7 8 9 10 11 12 13 14

Hal

f-Life

(hrs

)

0.0001

0.001

0.01

0.1

1

10

100

1000

ChlorineHydrolysis

Chen, 2011

Loss in water heaters

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Liu et al., 2013 In review

Reaction Time (hr)

0 20 40 60 80 100 120

CP

( g/

L)

0.0

0.1

0.2

0.3

0.4

0.5

0.6

No heating6 hrs incubation+heating24 hrs incubation+heating48 hrs incubation+heating72 hrs incubation+heating96 hrs incubation+heating

Reaction Time (hr)

0 20 40 60 80 100 120

TCP

( g/

L)

0.0

2.0

4.0

6.0

8.0No heating6 hrs incubation+heating24 hrs incubation+heating48 hrs incubation+heating72 hrs incubation+heating96 hrs incubation+heating

Reaction Time (hr)

0 20 40 60 80 100 120

DC

AN

( g/

L)

0.0

0.5

1.0

1.5

2.0

2.5

No heating6 hrs incubation+heating24 hrs incubation+heating48 hrs incubation+heating72 hrs incubation+heating96 hrs incubation+heating

Reaction Time (hr)

0 20 40 60 80 100 120

1,1-

DC

P (

g/L)

0.0

0.5

1.0

1.5

2.0

2.5

3.0No heating6 hrs incubation+heating24 hrs incubation+heating48 hrs incubation+heating72 hrs incubation+heating96 hrs incubation+heating

a b

c d

Profile of 1,1-DCP in Water Systems

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1,1-Dichloropropanone concentrations compared to the corresponding TTHM concentration for all samples

Chloroform (g/L)

0 20 40 60 80 100 120 140

1,1-

dich

loro

prop

anon

e (

g/L)

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

6.08.0

San Francisco Jan(Cl2/NH4Cl)Charleston(ClO2/ NH4Cl)San Francisco Apr (Cl2/NH4Cl)Ann Arbor(O3/NH4Cl)East Bay( Cl2/NH4Cl)Cincinnati(Cl2) Minneapolis (NH4Cl/NH4Cl)Monroe(O3/Cl2)Wyoming( Cl2/Cl2)Pinellas County(Cl2/Cl2) Pinellas County(Cl2/NH4Cl)Knoxville(ClO2/Cl2)

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1,1-Dichloropropanone concentrations compared to the corresponding TTHM concentration for all samples: focus on free chlorine plants

Chloroform (g/L)

0 20 40 60 80 100 120

1,1-

dich

loro

prop

anon

e (

g/L)

0.0

0.2

0.4

0.6

0.8

1.0San Francisco Jan(Cl2/NH4Cl)Charleston(ClO2/ NH4Cl)San Francisco Apr (Cl2/NH4Cl)Ann Arbor(O3/NH4Cl)East Bay( Cl2/NH4Cl)Cincinnati(Cl2) Minneapolis (NH4Cl/NH4Cl)Monroe(O3/Cl2)Wyoming( Cl2/Cl2)Pinellas County(Cl2/Cl2) Pinellas County(Cl2/NH4Cl)Knoxville(ClO2/Cl2)

Monroe

Cincinnati

Wyoming

Pinellas County

Profile of TCP in water systems

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1,1,1-Trichloropropanone concentrations compared to the corresponding TTHM concentration for all samples

Chloroform (g/L)

0 20 40 60 80 100 120 140

1,1,

1- tr

ichl

orop

ropa

none

(g/

L)

0

1

2

3

4

5San Francisco Jan(Cl2/NH4Cl)Charleston(ClO2/ NH4Cl)San Francisco Apr (Cl2/NH4Cl)Ann Arbor(O3/NH4Cl)East Bay( Cl2/NH4Cl)Cincinnati(Cl2) Minneapolis (NH4Cl/NH4Cl)Monroe(O3/Cl2)Wyoming( Cl2/Cl2)Pinellas County(Cl2/Cl2) Pinellas County(Cl2/NH4Cl)Knoxville(ClO2/Cl2)

Monroe

Pinellas Co.

Knoxville

Lab 2

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15 Oct 2013 experiment

Reaction Time (sec)

0 100 200 300

Abs

orba

nce

at 2

92 n

m

0.0

0.1

0.2

0.3

Time (s) vs Abs

absinf = 0.012

Lab 2

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1st order plot

Reaction Time (sec)

0 100 200 300

Ln (A

bs-A

bs

-6

-5

-4

-3

-2

-1

Time (s) vs ln abs-absinf Plot 1 Regr

b[1]-0.0128851211

absinf = 0.012

K = 46 hr-1

Lab 2

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2nd order plot

Reaction Time (sec)

0 100 200 300

1/(A

bs-A

bs

0

50

100

150

200

250

300

Time (s) vs 1/(abs-absinf) Plot 1 Regr

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Guthrie model

pH

4 5 6 7 8 9 10 11 12 13 14

Hal

f-Life

(hrs

)

0.0001

0.001

0.01

0.1

1

10

100

1000

ChlorineHydrolysis

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