3 TOC-THM Removal-16 - H2O'C Engineering · Granular Activated Carbon Fabricated at the University of Missouri-Columbia, the first pilot plant study of the removal of THM and TOC

TOC Removal Physical Removal of Particulates

Coagulation, Filtration Enhanced Precipitative (Lime) Softening Enhanced

Adsorption Granular Activated Carbon GAC Powdered Activated Carbon PAC Anion Exchange Resin MIEX Macroreticular Resin XE340

Oxidation KMnO4, O3, ClO2

Granular Activated Carbon

Fabricated at the University of Missouri-Columbia, the first pilot plant study of the removal of THM and TOC on GAC and macroreticular resins was conducted at the Kansas City water treatment plant in 1976-1977.

GAC Post-Adsorption for TOC

BBBBB

B

JJ

JJJJ H

HH

HHH

FFFFFF

B

BBBB

B

0

1

2

3

4

5

0 24 48 72

TOC

, mg

C /

l

Hours

B Raw

J Settled

H Filtered

F Clear Well

B GAC Post-adsorber

THM Formation

pH Time Temperature

Effect of pH on TTHMFP - St. Louis, MO

5.5 7.5 100

100

200

300

400

500

600TT

HM

FP, µ

g/l

pH

CHCl3BrCHCl2ClCHBr2CHBr3

Rate of TTHM Formation Mississippi River - St. Louis

B

B

B

B

B

B

BB

B

JJJJJJJJJ HHHHHHHHH FFFFFFFFF0

100

200

300

400

500

0 24 48 72 96 120 144 168

THM

Com

poun

ds, µ

g/l

Hours

B CHCl3J BrCHCl2H ClCHBr2F CHBr3

B BB

B B B B B B B B BJ JJ

J J J J J J J J JH H

HH H

HH H H

HH

HF FF

F F FF F F

FF F

2 4 5 12 13 20 21 24 25 26 39 460

20

40

60

80

100

120TT

HM

, µg/

l

Time, days

B East Settling Basin

J West Settling Basin

H North Filter

F South Filter

Clear Well #2

Clear Well #4

TTHM Formation During Treatment

Increasing time of chlorine contact

B B B B B B B BB

BB B

B B B B B B B B BJ J

JJ

J J J JJ

JJ J J J J J

J JJ J JH H

HH

H H H HH H H H H H H H H H H H H

F F F F

F F F FF

F

F FF F

FF F F F

F F

2 4 5 6 10 17 18 19 20 21 24 25 26 27 28 39 46 55 62 89 950

10

20

30

40

50

60

70

80TT

HM

, µg/

l

Days

B Settling Basin #2J Settling Basin #3H Settling Basin #4F East Filter West Filter Clear Well #1 Clear Well #2

TTHM Formation During Treatment

Increasing time of chlorine contact

Seasonality of THM Formation

B

B

BB

B

B

B

B

B

B

B

B

J

J JJ

J

J

J

J

J

J

J

J

HH H H

H H

H H H HH

H

FF F F

F F

F FF F

F F

2/98 5/98 8/98 11/98 2/99 5/99 8/99 11/99 2/00 5/00 8/00 11/00012345

50

100

150

200

250

300

TOC,

mg/

l

TTH

M, µ

g/l

B dist. sys. avg. THM

J plant tap THM

H raw water TOC

F filter influent TOC

Effects of Temperature on TTHM

TTHM, µg / l Winter Summer > 100 0 3 80-100 0 6 60-80 0 19 40-60 3 53 <40 97 19

THM Removal

Aeration Air stripping

Adsorption

Activated Carbon Synthetic Exchange Resins

Lake Settled Wilson Ozark GAC-Cap GAC 10m GAC 20m0

50

100

150

200

250

TTH

MFP

, Hal

oace

tic A

cids

, µg

/ l

TTHMFP7HAA6

TTHMFP and HAA Removal on GAC

Raw

Wat

er

Alu

m

+ 10

mg/

l PA

C

+ 20

mg/

l PA

C

+ 40

mg/

l PA

C

+ 50

mg/

l PA

C

Raw

Wat

er

Alu

m

+ 1

mg/

l KM

nO4

+ 2

mg/

l KM

nO4

+ 3

mg/

l KM

nO4

+ 5

mg/

l KM

nO4

Raw

Wat

er

Alu

m

KM

nO4

(2m

g/l)

KM

nO4

+ 10

mg/

l PA

C

KM

nO4

+ 20

mg/

l PA

C

KM

nO4

+ 40

mg/

l PA

C

0

20

40

60

80

100

120

140

160TT

HM

FP, µ

g/l

PAC KMnO4 PAC + KMnO4

Effect of PAC, KMnO4 on TTHMFP

B

BB

BB

J

JJJJ

J

H

HHH

H

HF

F

FF

F

F

0

50

100

150

200

250

0 30 60 90 120 150 180 210

THM

-form

ing

Pote

ntia

l, µ

g C

HC

l3 /

l

Days after Start of Pilot GAC Columns

B Lake

J Settled

H Wilson

F Ozark Pt.

GAC-capped

GAC 10 m

GAC 20 m

GAC Post-Adsorption for TTHMFP

Trihalomethane Formation Potential (TTHMFP)

Determination of maximum potential for TTHM formation after seven days

in distribution system

•  Add chlorine to water in excess of seven day chlorine demand

•  Measure TTHM after seven days

J

J

J

J

JJJJJ

JJ

JJ

J

J

J

J

J

J

JJJ

J

J0

50

100

150

200

250

0 1 2 3 4 5

TTH

M F

orm

ing

Pote

ntia

l, µg

/l

Chlorine Consumption, mg Cl/l

TTHMFP and Chlorine Consumption

Dechlorination

Sulfur Dioxide SO2 !^ SO42-"

Sodium Sulfite Na SO3 ^ SO42-"

Activated Carbon C ^ CO2