Treating Cyanotoxins with Granular Activated...

Treating Cyanotoxins with Granular Activated Carbon

Kendra RyanCalgon Carbon Corporation

Municipal Applications Engineer

Ralph Franco PECalgon Carbon Corporation

Director – Municipal Products

• Background – Algae: Cyanotoxin Compounds‒ Formation Conditions‒ Most Common Cyanotoxins‒ Treatment Approaches

• Activated Carbon‒ Adsorption & Starting Material Basics‒ Activated Carbon in Water Treatment - PAC & GAC‒ Performance Studies

Presentation Overview

Algae & Cyanotoxins

• Naturally occurring organisms• Thrive under certain conditions:‒ Sunlight‒ Warm temperatures‒ Slow Moving Water (i.e. Lakes/Reservoirs)‒ Excess nutrients Nitrogen Phosphorous Potassium

• Harmful Algal Blooms (HABs) ‒ Typical season duration = 3 months‒ Promote growth of cyanobacteria

Algae Formation

Satellite Image of Blue-Green Algal Outbreak on Lake Erie, 2011

• By-product of cyanobacteria life cycle‒ Over 3,000 known species

• 2 primary classes:‒ Hepatotoxin – affecting the liver‒ Neurotoxin – affecting nerves & nervous system

• 4 primary toxins of interest:‒ Anatoxin-A‒ Cylindrospermopsin‒ Microcystin-LR‒ Saxitoxin

Cyanotoxins

• Shut-off intake‒ Sufficient Warning‒ Multiple source water options

• Treatment Approaches‒ Adsorption via Powder Activated Carbon‒ Adjustment of Pretreatment chemistry‒ Ozone Oxidation‒ Adsorption via Granular Activated Carbon‒ Reverse Osmosis (RO)‒ UV Advanced Oxidation (UV/AOP)‒ Adjustment of oxidant levels

Operational Options

Introduction to Activated Carbon

Structure of Activated Carbon

• Carbon is the base element of graphite

AC is 99%

graphite

• Imperfections result in porosity and greater surface area

AC is a crude

form of graphite

Bituminous CoalCoconut Shell

Sub-BituminousLignitePeatWood

Starting Materials

Starting Materials

• Ash impurities• Density• Hardness• Transport pore structure• Adsorption kinetics

Raw material dictates all of the product possibilities

≠

Manufacturing Processes

Direct Reagglomerated

Over activation in the outer Part of the granule

Low Activation Even Activation

Granular Activated CarbonProduct differences: Re-agglomeration versus Direct Activation

Granular Activated Carbon

Where is it Used?

Disinfection Byproducts (DBPs)•Trihalomethanes

(THMs)•Haloacetic Acids

(HAA5s)

Carcinogenic VOCs•TCE•PCE

Perfluorinated Compounds (PFCs)•PFOA•PFOS

Algal Toxins•Microcystin•Cylindros-

permopsin•Anatoxin A

Pesticides•1,2,3 –

Trichloropropane (1,2,3-TCP)

•Dieldrin•Glyphosate

EDCs & PCPPs•Medicine•Pharmaceuticals

Defense Barrier•Chemical Spills

Simultaneous Contaminant RemovalUSEPA considers GAC to be an effective treatment technology for:

Economic Benefit of GAC

The average family of 4 consumes 65,700 gallons of water annually

Tap water filtered by GAC costs a family of 4 roughly $2.00/Month (per

AWWA)

The average 2015 price for bottled water is $1.22/gallon

Performance Testing

Importance of Testing•Many factors influence the effective service life of GAC

•Temperature•pH•EBCT•Concentration•Competitive Adsorption

•Extremely difficult to quantify without testing

Why

• Feasibility• Product Comparison• Service Life Estimation• Treatment Technology Comparison

Goals

•Bench Scale•TACTIC•Isotherm •ACT/RSSCT

•In-Process•Pilot Column

Types

Equilibrium batch carbon adsorption tests‒Series of carbon dosages allowed to equilibrate

INCREASING DOSE OF CARBON

Isotherm

Accelerated Column Test (ACT)

•fluctuations in influent•flow rate•pH•bio activity•temperature•TSS•physical filtration•backwashable

Incorporates

Pilot Column

Removal Case Studies

Ohio EPA Monitoring Website

• Surface Water Upstream of GAC contactors

• NOM/TOC present Average feed = 2.1 mg/L

• Spiked with cyanotoxins Anatoxin-A feed = 86 µg/L Cylindrospermopsin feed = 45 µg/L Microcystin-LR feed = 55 µg/L

• Contact Time (EBCT) 7 minutes

Cyanotoxin Case Study #1

• Filtrasorb 300‒ Reagglomerated bituminous coal‒ 8x30 mesh‒ 900 mg/g Iodine Number‒ Virgin


Cyanotoxin Case Study #1 – Anatoxin-A

0

10

20

30

40

50

60

70

0

0.5

1

1.5

2

2.5

3

0 20,000 40,000 60,000 80,000 100,000 120,000 140,000

Mic

rocy

stin

-LR

Conc

entra

tion

(ppb

)

TOC

Conc

entra

tion

(ppm

)

Bed Volumes Treated (BV)

TOC and Microcystin-LR vs Bed Volumes Treated

TOC TOC Feed MC-LR MC-LR Feed

Cyanotoxin Case Study #1 – Cylindrospermopsin

0

10

20

30

40

50

60

0

0.5

1

1.5

2

2.5

3

0.0 20000.0 40000.0 60000.0 80000.0 100000.0 120000.0 140000.0

Cylin

dros

perm

opsi

n Co

ncen

tratio

n (p

pb)

TOC

Conc

entra

tion

(ppm

)


TOC and Cylindrospermopsin vs Bed Volumes Treated

TOC TOC Feed CYN CYN Feed

Cyanotoxin Case Study #1 – Microcystin-LR

0

5

10

15

20

25

30

0

0.5

1

1.5

2

2.5

3

0.0 20000.0 40000.0 60000.0 80000.0 100000.0 120000.0 140000.0

Anat

oxin

-a C

once

ntra

tion

(ppb

)

TOC

Conc

entra

tion

(ppm

)


TOC and Anatoxin-a vs Bed Volumes Treated

TOC TOC Feed ANTX-a ANTX-a Feed

• 676 days simulated‒ ~245 million gallons water

• Cyanotoxin breakthrough ‒ Initial breakthrough = 52 days‒ 50-70% breakthrough at conclusion

• TOC breakthrough‒ ~60% breakthrough at first cyanotoxin detection


• Surface Water Upstream of GAC contactors

• NOM/TOC present Average feed = 2.1 mg/L

• Spiked with cyanotoxins Anatoxin-A feed = 86 µg/L Cylindrospermopsin feed = 45 µg/L Microcystin-LR feed = 55 µg/L

• Contact Time (EBCT) 15 minutes


• Filtrasorb 400‒ Reagglomerated bituminous coal‒ 12x40 mesh‒ 1,000 mg/g Iodine Number‒ Virgin and reactivated GAC


Cyanotoxin Case Study #2 – Anatoxin-A

0

20

40

60

80

100

120

0

0.5

1

1.5

2

2.5

0.0 50.0 100.0 150.0 200.0 250.0

Anat

oxin

-a (p

pb)

TOC

Conc

entra

tion

(ppm

)

Simulated Days of Operation

TOC and Anatoxin-a vs Simulated Days

F-400 TOC CMR F-400 TOC F-400 Feed ANTX-a F-400 ANTX-a CMR F-400 ANTX-a

Cyanotoxin Case Study #2 – Cylindrospermopsin

0

5

10

15

20

25

30

35

40

45

50

0

0.5

1

1.5

2

2.5

0.0 50.0 100.0 150.0 200.0 250.0

Cylin

dros

perm

opsi

n (p

pb)

TOC

Conc

entra

tion

(ppm

)


TOC and Cylindrospermopsin vs Simulated Days

F-400 TOC CMR F-400 TOC Feed TOC Feed Cyn F-400 Cyn CMR F-400 Cyn

Cyanotoxin Case Study #2 – Microcystin-LR

0

10

20

30

40

50

60

70

0

0.5

1

1.5

2

2.5

0.0 50.0 100.0 150.0 200.0 250.0

Mic

rocy

stin

-LR

(ppb

)

TOC

Conc

entra

tion

(ppm

)


TOC and Microcystin-LR vs Simulated Days

CMR F-400 TOC F-400 TOC Feed TOC Feed MC-LR F-400 MC-LR CMR F-400 MC-LR

Cyanotoxin Case Study #2 – THM Formation

0

10

20

30

40

50

60

70

80

90

100

0.0 50.0 100.0 150.0 200.0 250.0

THM

FP (p

pb)


THMFP vs Simulated Days

F-400 THMFP CMR F-400 THMFP

• 230 days simulated‒ ~53 million gallons water

• No Cyanotoxin breakthrough ‒ Virgin & reactivated GACs‒ Anatoxin-A detection limit = 0.6 µg/L ‒ Cylindrospermopsin detection limit = 0.03 µg/L ‒ Microcystin-LR detection limit = 0.15 µg/L

• TOC breakthrough‒ Virgin = 74% of influent‒ React = 82% of influent


• Reagglomerated bituminous coal GAC can be an effective barrier against Anatoxin-A, Cylindrospermopsin, and Microcystin-LR.‒ Both virgin and reactivated‒ Non-detect longer than HAB season‒ Still effective near end of GAC service life for TOC removal/DBP

prevention

Conclusion

Summary

• Activated Carbon can be an effective tool for the treatment of Cyanotoxins

• Its important to properly maintain your GAC filters to assure that proper treatment can be obtained during a Harmful Algal Bloom

• Not all Carbons are the same; there are benefits to pilot testing with your specific water to determine the best carbon for your application

Final Takeaways

Thank you for your time.

Questions?

Ralph Franco PEDirector – Municipal ProductsP: 412-787-6620E: [email protected]

Treating Cyanotoxins with Granular Activated...

Documents

Transcript of Treating Cyanotoxins with Granular Activated...