Natural and Engineering Factors that Affect Disinfection Byproduct Concentrations in the Home Boning...

Natural and Engineering Factors that Affect Disinfection Byproduct Concentrations in the Home

Boning Liu and David ReckhowDepartment of Civil and Environmental Engineering, University of Massachusetts, Amherst, MA 01003

2

OUTLINE

Intro & DBP Issue Factors affecting

DBP formation Information Gaps Field Studies

Design Municipal system Home impacts

Conclusions

Let’s make some disinfection byproducts!

INTRO & DBP ISSUE

HOCl + natural organics (NOM)

Oxidized NOMand inorganic chloride

• Aldehydes

Chlorinated Organics• TOX• THMs• HAAs

Cl

Cl

Cl C H

Br

Cl

Cl C HBr

Cl

Br C H

Br

Br

Br C H

Chloroform Bromodichloromethane ChlorodibromomethaneBromoform

The THMs MCL 80µg/L

The Precursors!

4

FACTORS AFFECTING DBP LEVELS

Raw water NOM levels (e.g., TOC) Specific precursor content of the RW NOM NOM removal Disinfection regime

type & dose location in plant contact time & temperature pH

Degradation and formation in DS

Wate r

Heat

er

CityWater

Drinking

Showering &Washing

Dermal &Inhalation

Beverage Preparation

FoodPreparation

Ingestion

Ingestion &Inhalation

Clothes Washing Dermal &Inhalation

Ingestion &Inhalation

Hum

an E

xpos

ure

Activity Major Routes

Dish Washing Dermal &Inhalation

EPA regulation based

MULTIPLE ROUTES OF EXPOSURE

Inhalation in the shower produces highest blood level and response is fast

6

Gordon et al., 2006 [Env. Hlth Persp.114:514-521]

TOX: KNOWN & UNKNOWN

Trihalomethanes20%

Sum of 5 Haloacetic Acids10%

Bromochloroacetic Acid3%

Unknown Organic Halogen64%

Chloral Hydrate1%

Haloacetonitriles2%

HaloketonesChloropicrin

Data from the Mills Plant (CA) August 1997 (courtesy of Stuart Krasner)

RegulatedDBPs

But, the Bad Stuff

is probably

somewhere here

KEY STUDY QUESTIONS

What is the extent of diurnal variations in regulated and non-regulated DBPs? In mains, near storage tanks, in dead ends

How does actual exposure compare to expectations from compliance testing? Hot water effects(tankless vs. tank heater) Non-regulated DBPs

CASE STUDIES: NORTHAMPTON, MA

d

9

HISTORICAL WATER QUALITY

Relatively low TOC

11

2D Graph 1

Month of Year

Jan

Feb

Mar

chApr

ilM

ayJu

ne July

Augus

tSep

tOct

Nov Dec

TO

C (

mg/

L)

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

Ryan meanRyan medianMt Street mean Mt Street median

HISTORICAL DATA(CONT.)

12Date

1/1/

2004

1/1/

2005

1/1/

2006

1/1/

2007

1/1/

2008

1/1/

2009

TT

HM

s (

g/L)

0

20

40

60

80

100

120

140

AMERICAN PACKING COMPANY CITY HALL FLORENCE FIRE STATION WELFARE DEPT Plant goes

on-line

Recent DBP levels have dropped due to new WTP

FIELD STUDY 1 DESIGN

Intensive sampling over 2 days Monitor cold water

Plant effluent: system entry Distribution system location unaffected by

storage and dead end Monitor hot water

Measure regulated and non-regulated DBPs THMs, HAAs, residual chlorine, temp TOX, HANs, CP, TCP

STUDY #1 DESIGN

Don’t try this at home

dsa

15

Field Site #1

Total transit time is around 18-30 hours

PLANT TO TAP: CHLORINE RESIDUAL

16:

00

18:

00

20:

00

22:

00

00:

00

02:

00

04:

00

06:

00

08:

00

10:

00

12:

00

14:

00

16:

00

18:

00

20:

00

22:

00

00:

00

02:

00

04:

00

06:

00

08:

00

Res

idua

l Chl

orin

e C

once

ntra

tion

(mg/

L)

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

Day and Time

Cold TapSimulated DS

Monday Tuesday Wednesday

Sample collected from Plantand incubated in lab

PLANT TO TAP: TTHM

16:

00

18:

00

20:

00

22:

00

00:

00

02:

00

04:

00

06:

00

08:

00

10:

00

12:

00

14:

00

16:

00

18:

00

20:

00

22:

00

00:

00

02:

00

04:

00

06:

00

08:

00

TT

HM

Con

cent

ratio

n (

g/L)

0

2

4

6

8

10

12

14

16

Day and Time

Cold TapPlant EffluentSimulated DS



http://upload.wikimedia.org/wikipedia/commons/9/9f/Chloroform_displayed.svg

TRIHALOACETIC ACIDS

16:

00

18:

00

20:

00

22:

00

00:

00

02:

00

04:

00

06:

00

08:

00

10:

00

12:

00

14:

00

16:

00

18:

00

20:

00

22:

00

00:

00

02:

00

04:

00

06:

00

08:

00

Trih

aloa

cetic

Aci

d C

once

ntra

tion

(g/

L)

0

2

4

6

8

10

12

Day and Time

Cold TapPlant EffluentSimulated DS



C C

O

O

Cl

Cl

Cl

MONITORING HOT WATER

temp

19

16:

00

18:

00

20:

00

22:

00

00:

00

02:

00

04:

00

06:

00

08:

00

10:

00

12:

00

14:

00

16:

00

18:

00

20:

00

22:

00

00:

00

02:

00

04:

00

06:

00

08:

00

Wat

er T

empe

ratu

re (

oC

)

0

10

20

30

40

50

60

Day and Time

Cold TapHot Tap


Heavy Hot Water UseWater Heater is Flushed

RESULTS-HOT VS COLD: TTHM

16:

00

18:

00

20:

00

22:

00

00:

00

02:

00

04:

00

06:

00

08:

00

10:

00

12:

00

14:

00

16:

00

18:

00

20:

00

22:

00

00:

00

02:

00

04:

00

06:

00

08:

00

TT

HM

Con

cent

ratio

n (

g/L)

0

10

20

30

40

50

Day and Time

Cold TapHot TapPlant Effluent


Hwang's level of concern


http://upload.wikimedia.org/wikipedia/commons/9/9f/Chloroform_displayed.svg

HOT VS COLD: DIHALOACETIC ACIDS

16:

00

18:

00

20:

00

22:

00

00:

00

02:

00

04:

00

06:

00

08:

00

10:

00

12:

00

14:

00

16:

00

18:

00

20:

00

22:

00

00:

00

02:

00

04:

00

06:

00

08:

00

Dih

aloa

cetic

Aci

d C

once

ntra

tion

(g/

L)

0

5

10

15

20

25

30

Day and Time




HC C

O

O

Cl

Cl

HOT VS COLD: TRIHALOACETIC ACIDS

16:

00

18:

00

20:

00

22:

00

00:

00

02:

00

04:

00

06:

00

08:

00

10:

00

12:

00

14:

00

16:

00

18:

00

20:

00

22:

00

00:

00

02:

00

04:

00

06:

00

08:

00

Trih

aloa

cetic

Aci

d C

once

ntra

tion

(g/

L)

0

5

10

15

20

Day and Time




Northampton, MA

C C

O

O

Cl

Cl

Cl

TOX

23

16:

00

18:

00

20:

00

22:

00

00:

00

02:

00

04:

00

06:

00

08:

00

10:

00

12:

00

14:

00

16:

00

18:

00

20:

00

22:

00

00:

00

02:

00

04:

00

06:

00

08:

00

TO

X C

once

ntra

tion

(g/

L)

0

20

40

60

80

100

Day and Time




Percentage of Unknown TOX little changed 50% for cold water 45% for hot water

ALTERNATIVE EXPLANATION

If TCAA decarboxylation isn’t the explanation, then what?

Answer: Shift in reaction pathway for common THM/TCAA intermediate

24

THMs TriHAAs

R'

C

C

R"

O

Cl Cl

Cl2HC

C

R"

O

Cl3C

C

R"

O

CHCl3TCAADCAA

NOMHOCl/OCl-

HOCl/OCl-

HOClOH-

or heatSimplified from: Reckhow & Singer, 1985 [Water Chlorination: Environmental Impact and Health Effects, Vol 5, pp1229-1257.]

HOT VS COLD: DICHLOROACETONITRILE

16:

00

18:

00

20:

00

22:

00

00:

00

02:

00

04:

00

06:

00

08:

00

10:

00

12:

00

14:

00

16:

00

18:

00

20:

00

22:

00

00:

00

02:

00

04:

00

06:

00

08:

00

Dic

hlor

oace

tont

rile

Con

cent

ratio

n (

g/L)

0.0

0.5

1.0

1.5

2.0

2.5

Day and Time




HC C

Cl

Cl

N

DHAN

Key intermediate

Concentrations are well known

C NC

H

Cl

Cl

CC

H

Cl

Cl

O

OH

CC

H

Cl

Cl

N

OH

CC

H

Cl

Cl

NH

OH

CC

H

Cl

Cl

N

OCl

CC

H

Cl

Cl

NH2

O

CC

H

Cl

Cl

NHCl

O

H2O

NHCl2NH3

Cl(+II)

S (+IV)

CC

H

Cl

Cl

NCl

O

CC

H

Cl

Cl

NHCl

OCl

OH

CC

H

Cl

Cl

NH2

OH

O

pKa = 3.7

H2O

fast fast

fast

fast

fast

k2

k1

k4

k1-2k1-1

DCAN

DCAD

DCAA

HOCl

OClOH

OH

OH

N-Cl-DCAD

N-Cl-DCADanion

HOT VS COLD: TRICHLOROPROPANONE

16:

00

18:

00

20:

00

22:

00

00:

00

02:

00

04:

00

06:

00

08:

00

10:

00

12:

00

14:

00

16:

00

18:

00

20:

00

22:

00

00:

00

02:

00

04:

00

06:

00

08:

00

1,1,

1-T

richl

orop

ropa

none

Con

cent

ratio

n (

g/L)

0.0

0.5

1.0

1.5

2.0

2.5

Day and Time




C C

Cl

Cl

Cl CH3

O

HOT VS COLD: CHLOROPICRIN

16:

00

18:

00

20:

00

22:

00

00:

00

02:

00

04:

00

06:

00

08:

00

10:

00

12:

00

14:

00

16:

00

18:

00

20:

00

22:

00

00:

00

02:

00

04:

00

06:

00

08:

00

Chl

orop

icrin

Con

cent

ratio

n (

g/L)

0.0

0.2

0.4

0.6

Day and Time




Northampton, MA

http://upload.wikimedia.org/wikipedia/commons/c/ce/Chloropicrin.png

FIELD STUDY 2IMPACT OF HEATERS ON DBP FORMATION

Rocky Hill Cohousing Community, Northampton, MA Uniform construction: completed 2005

Study date: late July 2010 18 homes participated

8 tankless gas heaters, 10 conventional tank heaters

FIELD STUDY 2IMPACT OF HEATERS ON DBP FORMATION

tankless heaters No storage tank

On-Demand, save energy, how about Disinfection byproducts?

EXPERIMENTAL DESIGN

2 day sampling Temperature controlled Chlorine residual/pH measured

at each site Samples quenched, cooled

down and transported to lab for DBP analysis

Simulated experiments

TEMPERATURE

Day/Time

Thu 22 Thu 22 Fri 23 Fri 23 Fri 23

Te

mp

era

ture

(o C)

10

20

30

40

50

60

70

temperature for cold taptemperature for hot tap

Reading is after flushing when temperature is stabilized

Hot Water: 50-60 C

Cold Water: 18-22 C

TANKLESS VS. TANK HEATER(DHAA)

Heavy water usage

Dih

alo

ace

tic A

cid

Co

nce

ntr

atio

n( g

/L)

0

5

10

15

20

25

30

TC

R(m

g/L

)

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

DHAA in cold water for tanklessDHAA in hot water for tanklessDHAA in cold water for tank DHAA in hot water for tankTCR in Cold Water for tanklessTCR in Hot Water for tanklessTCR in Cold Water for tank heaterTCR in Hot Water for tank heater

TANKLESS VS. TANK HEATER(DHAA)

Delta value, ratio

Delta

( g

/L)

0

1

2

3

4

5

6

Tankless heaterTank heater

Ratio

(Ch/C

o)

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8


TANKLESS VS. TANK HEATER(THAA)

Trih

alo

ace

tic A

cid

s C

on

ce

ntr

atio

n(

g/L

)

0

2

4

6

8

10

12THAA in Cold Tap for TanklessTHAA in Hot Tap for Tankless THAA in Cold Tap for TankTHAA in Hot tap for Tank

TANKLESS VS. TANK HEATER(THAA)

Del

ta fo

r TH

AA(

g/L

)

-1.8

-1.6

-1.4

-1.2

-1.0

-0.8

-0.6

-0.4

-0.2


Rat

io(C

h/C

c)

0.0

0.2

0.4

0.6

0.8

1.0

1.2


TANKLESS VS. TANK HEATER(TTHM)T

TH

M c

on

ce

ntr

atio

n(m

g/L

)

0

10

20

30

40

50

TTHM in cold tap for TanklessTTHM in hot tap for TanklessTTHM in cold tap for TankTTHM in hot tap for Tank

Delta

( g

/L)

0

2

4

6

8

10

12

14


TANKLESS VS. TANK HEATER(TTHM)

ratio

(Ch/

Cc)

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8


CONCLUSIONS & NEXT STEPS

Water Heaters substantially change the DBP levels and character Some increase many fold

THMs, DiHAAs, Chloropicrin Some show little change

TriHAAs Some decrease

Dichloroacetonitrile, Trichloropropanone

For most, we simply don’t know

Tankless heaters have a smaller affect

High temperatures shift reaction pathways TriHAA→THM Other products formed? What does this mean to

exposure studies? Need to look at other

DBPs and develop models Hypothesis: DBP increase

is related to chlorine residual at time of heating

39

ACKNOWLEDGEMENTS

Northampton (MA) DPW - Water Division David Sparks, superintendent Alex Roseweir, Doug Ducharme, Paul

Petersen Northampton Rocky Hill cohousing

community 18 anonymous home owners

40

DICHLOROACETONITRILE

Day/Time

Thu 22 10:00:00 Thu 22 18:00:00 Fri 23 2:00:00 Fri 23 10:00:00 Fri 23 18:00:00

Dic

hlo

roac

eton

itrile

(g/

L)

0.0

0.5

1.0

1.5

2.0

2.5

3.0


CHOROPICRIN

Day/Time

Thu 22 9:00:00 Thu 22 17:00:00 Fri 23 1:00:00 Fri 23 9:00:00 Fri 23 17:00:00

Chl

orop

icrin

Con

cent

ratio

n( g

/L)

0.0

0.2

0.4

0.6

0.8

1.0


LAB-INCUBATED SAMPLES

Total Chlorine Residual

Day/Time

Thu 11:00:00 Thu 19:00:00 Fri 03:00:00 Fri 11:00:00

TC

R(m

g/L

)

0.0

0.2

0.4

0.6

0.8

1.0

1.2

Plant effluent incubatedMixed water for lab heating

Mixed cold water from cohousing homes, incubated at 53oC(average T of hot tap) Incubated water effluent from water treatment plant

LAB INCUBATED SAMPLES(CONT.)

Day/Time

Thu 22 11:00:00 Thu 22 19:00:00 Fri 23 3:00:00 Fri 23 11:00:00

TT

HM

co

nce

ntr

atio

n( g

/L)

15

20

25

30

35

40

45

Lab Heating@53oCPlant Effluent incubated@17oC

Day/Time

Thu 10:00:00 Thu 18:00:00 Fri 02:00:00 Fri 10:00:00

DiH

AA

(g/L

)

0

5

10

15

20

25

plant effluent incubated@17oC

Mixed water heating@53oC

Day/Time

Thu 11:00:00 Thu 19:00:00 Fri 03:00:00 Fri 11:00:00

TriH

AA

( g

/L)

0

2

4

6

8

10

12

plant effluent incubated@17oC

mixed water incubated@53oC

TTHMDHAA

THAA

Immediately 53oC

TCAA DEGRADATION KINECTICS

reaction time (hr)

0 5 10 15 20 25 30 35

Con

cent

ratio

n (u

mol

/L)

-20

0

20

40

60

80

100

120

140

160

[TCAA]+[CHCl3][TCAA][CHCl3]

Reaction Time(hours)

0 10 20 30

LnC

4.0

4.2

4.4

4.6

4.8

5.0

First order fitted linelnC

pH=6.7, temperature 60oC, TCAA standard solution. Calculated K=( 0.0169 +/- 0.0025 )/hr

THE HALOACETIC ACIDS

Cl

Cl

Cl C COOH

Br

Cl

Cl C COOHBr

Cl

Br C COOH

Br

Br

Br C COOH

Trichloroacetic Bromodichloroacetic Chlorodibromoacetic TribromoaceticAcid Acid Acid Acid

(TCAA)

Cl

Cl

H C COOH

Br

Cl

C COOHBr

Br

H C COOH

Dichloroacetic Bromochloroacetic DibromoaceticAcid Acid Acid

(DCAA)

H

MCL: 60µg/L

THM TERMINAL

47

16:

00

18:

00

20:

00

22:

00

00:

00

02:

00

04:

00

06:

00

08:

00

10:

00

12:

00

14:

00

16:

00

18:

00

20:

00

22:

00

00:

00

02:

00

04:

00

06:

00

08:

00

TT

HM

Con

cent

ratio

n (

g/L)

0

10

20

30

40

50

Day and Time

Cold TapHot TapPlant EffluentHot Tap TerminalCold Tap Terminal


Hwang's level of concern


Less than with the hot tap

DIHAA TERMINAL

48

16:

00

18:

00

20:

00

22:

00

00:

00

02:

00

04:

00

06:

00

08:

00

10:

00

12:

00

14:

00

16:

00

18:

00

20:

00

22:

00

00:

00

02:

00

04:

00

06:

00

08:

00

Dih

aloa

cetic

Aci

d C

once

ntra

tion

(g/

L)

0

5

10

15

20

25

30

Day and Time



Heavy Hot Water UseWater Heater is Flushed Little

difference between hot and cold

TRIHAA TERMINAL

49

16:

00

18:

00

20:

00

22:

00

00:

00

02:

00

04:

00

06:

00

08:

00

10:

00

12:

00

14:

00

16:

00

18:

00

20:

00

22:

00

00:

00

02:

00

04:

00

06:

00

08:

00

Tri

halo

acet

ic A

cid

Con

cent

ratio

n (

g/L)

0

5

10

15

20

Day and Time



Heavy Hot Water UseWater Heater is Flushed Higher

terminal levels in cold tap

Natural and Engineering Factors that Affect Disinfection Byproduct Concentrations in the Home Boning...

Documents

Transcript of Natural and Engineering Factors that Affect Disinfection Byproduct Concentrations in the Home Boning...