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Natural and Engineering Factors that Affect Disinfection Byproduct Concentrations in the Home. Boning Liu and David Reckhow Department of Civil and Environmental Engineering, University of Massachusetts, Amherst, MA 01003. Let’s make some disinfection byproducts!. Outline. Intro & DBP Issue - PowerPoint PPT Presentation
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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
ClCl C H
Br
ClCl C H
Br
ClBr C H
Br
BrBr 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
Wat
er
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 Relative
ly low TOC
11
2D Graph 1
Month of Year
Jan
FebMarc
hApri
lMay
June Ju
ly
Augus
tSep
tOct
Nov Dec
TOC
(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
1/1/20
04
1/1/20
05
1/1/20
06
1/1/20
07
1/1/20
08
1/1/20
09
TTH
Ms
(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
16:0
0
18:0
0
20:0
0
22:0
0
00:0
0
02:0
0
04:0
0
06:0
0
08:0
0
10:0
0
12:0
0
14:0
0
16:0
0
18:0
0
20:0
0
22:0
0
00:0
0
02:0
0
04:0
0
06:0
0
08:0
0
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
16:0
0
18:0
0
20:0
0
22:0
0
00:0
0
02:0
0
04:0
0
06:0
0
08:0
0
10:0
0
12:0
0
14:0
0
16:0
0
18:0
0
20:0
0
22:0
0
00:0
0
02:0
0
04:0
0
06:0
0
08:0
0
TTH
M C
once
ntra
tion
(g/
L)
0
2
4
6
8
10
12
14
16
Day and Time
Cold TapPlant EffluentSimulated DS
Monday Tuesday Wednesday
Sample collected from Plantand incubated in lab
TRIHALOACETIC ACIDS
16:0
0
18:0
0
20:0
0
22:0
0
00:0
0
02:0
0
04:0
0
06:0
0
08:0
0
10:0
0
12:0
0
14:0
0
16:0
0
18:0
0
20:0
0
22:0
0
00:0
0
02:0
0
04:0
0
06:0
0
08:0
0
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
Monday Tuesday Wednesday
Sample collected from Plantand incubated in lab
C C
O
O
Cl
Cl
Cl
MONITORING HOT WATER temp
19
16:0
0
18:0
0
20:0
0
22:0
0
00:0
0
02:0
0
04:0
0
06:0
0
08:0
0
10:0
0
12:0
0
14:0
0
16:0
0
18:0
0
20:0
0
22:0
0
00:0
0
02:0
0
04:0
0
06:0
0
08:0
0
Wat
er T
empe
ratu
re (o C
)
0
10
20
30
40
50
60
Day and Time
Cold TapHot Tap
Monday Tuesday Wednesday
Heavy Hot Water UseWater Heater is Flushed
RESULTS-HOT VS COLD: TTHM
16:0
0
18:0
0
20:0
0
22:0
0
00:0
0
02:0
0
04:0
0
06:0
0
08:0
0
10:0
0
12:0
0
14:0
0
16:0
0
18:0
0
20:0
0
22:0
0
00:0
0
02:0
0
04:0
0
06:0
0
08:0
0
TTH
M C
once
ntra
tion
(g/
L)
0
10
20
30
40
50
Day and Time
Cold TapHot TapPlant Effluent
Monday Tuesday Wednesday
Hwang's level of concern
Heavy Hot Water UseWater Heater is Flushed
HOT VS COLD: DIHALOACETIC ACIDS
16:0
0
18:0
0
20:0
0
22:0
0
00:0
0
02:0
0
04:0
0
06:0
0
08:0
0
10:0
0
12:0
0
14:0
0
16:0
0
18:0
0
20:0
0
22:0
0
00:0
0
02:0
0
04:0
0
06:0
0
08:0
0
Dih
aloa
cetic
Aci
d C
once
ntra
tion
(g/
L)
0
5
10
15
20
25
30
Day and Time
Cold TapHot TapPlant Effluent
Monday Tuesday Wednesday
Heavy Hot Water UseWater Heater is Flushed
HC C
O
O
Cl
Cl
HOT VS COLD: TRIHALOACETIC ACIDS
16:0
0
18:0
0
20:0
0
22:0
0
00:0
0
02:0
0
04:0
0
06:0
0
08:0
0
10:0
0
12:0
0
14:0
0
16:0
0
18:0
0
20:0
0
22:0
0
00:0
0
02:0
0
04:0
0
06:0
0
08:0
0
Trih
aloa
cetic
Aci
d C
once
ntra
tion
(g/
L)
0
5
10
15
20
Day and Time
Cold TapHot TapPlant Effluent
Monday Tuesday Wednesday
Heavy Hot Water UseWater Heater is Flushed
Northampton, MA
C C
O
O
Cl
Cl
Cl
TOX
23
16:0
0
18:0
0
20:0
0
22:0
0
00:0
0
02:0
0
04:0
0
06:0
0
08:0
0
10:0
0
12:0
0
14:0
0
16:0
0
18:0
0
20:0
0
22:0
0
00:0
0
02:0
0
04:0
0
06:0
0
08:0
0
TOX
Con
cent
ratio
n (
g/L)
0
20
40
60
80
100
Day and Time
Cold TapHot TapPlant Effluent
Monday Tuesday Wednesday
Heavy Hot Water UseWater Heater is Flushed
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
16:0
0
18:0
0
20:0
0
22:0
0
00:0
0
02:0
0
04:0
0
06:0
0
08:0
0
10:0
0
12:0
0
14:0
0
16:0
0
18:0
0
20:0
0
22:0
0
00:0
0
02:0
0
04:0
0
06:0
0
08:0
0
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
Cold TapHot TapPlant Effluent
Monday Tuesday Wednesday
Heavy Hot Water UseWater Heater is Flushed
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
16:0
0
18:0
0
20:0
0
22:0
0
00:0
0
02:0
0
04:0
0
06:0
0
08:0
0
10:0
0
12:0
0
14:0
0
16:0
0
18:0
0
20:0
0
22:0
0
00:0
0
02:0
0
04:0
0
06:0
0
08:0
0
1,1,
1-Tr
ichl
orop
ropa
none
Con
cent
ratio
n (
g/L)
0.0
0.5
1.0
1.5
2.0
2.5
Day and Time
Cold TapHot TapPlant Effluent
Monday Tuesday Wednesday
Heavy Hot Water UseWater Heater is Flushed
C C
Cl
Cl
Cl CH3
O
HOT VS COLD: CHLOROPICRIN
16:0
0
18:0
0
20:0
0
22:0
0
00:0
0
02:0
0
04:0
0
06:0
0
08:0
0
10:0
0
12:0
0
14:0
0
16:0
0
18:0
0
20:0
0
22:0
0
00:0
0
02:0
0
04:0
0
06:0
0
08:0
0
Chl
orop
icrin
Con
cent
ratio
n (
g/L)
0.0
0.2
0.4
0.6
Day and Time
Cold TapHot TapPlant Effluent
Monday Tuesday Wednesday
Heavy Hot Water UseWater Heater is Flushed
Northampton, MA
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
Tem
pera
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
aloa
cetic
Aci
d C
once
ntra
tion(
g/L)
0
5
10
15
20
25
30
TCR
(mg/
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
Rat
io(C
h/C
o)
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
Tankless heaterTank heater
TANKLESS VS. TANK HEATER(THAA)
Trih
aloa
cetic
Aci
ds C
once
ntra
tion(
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)D
elta
for T
HAA
(
g/L)
-1.8
-1.6
-1.4
-1.2
-1.0
-0.8
-0.6
-0.4
-0.2
Tankless heaterTank heater
Rat
io(C
h/C
c)
0.0
0.2
0.4
0.6
0.8
1.0
1.2
Tankless heaterTank heater
TANKLESS VS. TANK HEATER(TTHM)TT
HM
con
cent
ratio
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
Del
ta(
g/
L)
0
2
4
6
8
10
12
14
Tankless heaterTank heater
TANKLESS VS. TANK HEATER(TTHM)
ratio
(Ch/C
c)
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
Tankless heaterTank heater
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/TimeThu 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
hlor
oace
toni
trile
(g/
L)
0.0
0.5
1.0
1.5
2.0
2.5
3.0
Cold TapHot TapPlant Effluent
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
Cold TapHot TapPlant Effluent
LAB-INCUBATED SAMPLES
Total Chlorine Residual
Day/Time
Thu 11:00:00 Thu 19:00:00 Fri 03:00:00 Fri 11:00:00
TCR
(mg/
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
TTH
M c
once
ntra
tion(
g/L)
15
20
25
30
35
40
45
Lab Heating@53oCPlant Effluent incubated@17oC
Day/TimeThu 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@17oCMixed 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@17oCmixed 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 ACIDSCl
ClCl C COOH
Br
ClCl C COOH
Br
ClBr C COOH
Br
BrBr C COOH
Trichloroacetic Bromodichloroacetic Chlorodibromoacetic TribromoaceticAcid Acid Acid Acid
(TCAA)
Cl
ClH C COOH
Br
ClC COOH
Br
BrH C COOH
Dichloroacetic Bromochloroacetic DibromoaceticAcid Acid Acid
(DCAA)
H
MCL: 60µg/L
THM TERMINAL
47
16:0
0
18:0
0
20:0
0
22:0
0
00:0
0
02:0
0
04:0
0
06:0
0
08:0
0
10:0
0
12:0
0
14:0
0
16:0
0
18:0
0
20:0
0
22:0
0
00:0
0
02:0
0
04:0
0
06:0
0
08:0
0
TTH
M C
once
ntra
tion
(g/
L)
0
10
20
30
40
50
Day and Time
Cold TapHot TapPlant EffluentHot Tap TerminalCold Tap Terminal
Monday Tuesday Wednesday
Hwang's level of concern
Heavy Hot Water UseWater Heater is Flushed
Less than with the hot tap
DIHAA TERMINAL
48
16:0
0
18:0
0
20:0
0
22:0
0
00:0
0
02:0
0
04:0
0
06:0
0
08:0
0
10:0
0
12:0
0
14:0
0
16:0
0
18:0
0
20:0
0
22:0
0
00:0
0
02:0
0
04:0
0
06:0
0
08:0
0
Dih
aloa
cetic
Aci
d C
once
ntra
tion
(g/
L)
0
5
10
15
20
25
30
Day and Time
Cold TapHot TapPlant EffluentHot Tap TerminalCold Tap Terminal
Monday Tuesday Wednesday
Heavy Hot Water UseWater Heater is Flushed Little
difference between hot and cold
TRIHAA TERMINAL
49
16:0
0
18:0
0
20:0
0
22:0
0
00:0
0
02:0
0
04:0
0
06:0
0
08:0
0
10:0
0
12:0
0
14:0
0
16:0
0
18:0
0
20:0
0
22:0
0
00:0
0
02:0
0
04:0
0
06:0
0
08:0
0
Trih
aloa
cetic
Aci
d C
once
ntra
tion
(g/
L)
0
5
10
15
20
Day and Time
Cold TapHot TapPlant EffluentHot Tap TerminalCold Tap Terminal
Monday Tuesday Wednesday
Heavy Hot Water UseWater Heater is Flushed Higher
terminal levels in cold tap
