AUTONOMOUS, REAL TIME DETECTION OF 58 VOCS IN …apps.nelac-institute.org/nemc/2017/docs/pdf/Monday-Changing the... · • Long term, automated detection of VOCs in water of the Panama

AUTONOMOUS, REAL TIME DETECTION OF 58 VOCS IN THE PANAMA CANAL

Challenges of Water Monitoring

• Volatile Organic Compounds

(VOCs) can have negative

health impacts even at ppb

levels

• VOC concentrations can

fluctuate widely depending on

water system conditions

• Public water utilities are

concerned about sudden

spikes in VOC concentrations

caused by unexpected events

8/16/2017Autonomous, Real Time Detection of 58 VOCs in the Panama Canal 2

Site of chemical spill into the Elk River in

Charleston, WV

http://news.nationalgeographic.com/news


• How is water monitoring

accomplished?

• Manual collection of grab samples

• Problems

• Time consuming

• Difficult to collect enough samples

evaluate time trends

• Transport of samples: sample integrity

may be compromised

• Cost of third-party sample analysis

• Solution

• Automatic, integrated sampling

system


http://www.sacwsd.org


• How are VOCs in

water analyzed?

• Analytes must be

purged out of water

and into the gas phase

• Analysis by gas

chromatography (GC)

or gas chromatography

coupled with mass

spectrometry (GC-MS)


Challenges of GC Analysis

• USEPA Method

8260B

• 110 compounds via

GC-MS

• Complex

chromatogram

• Can a complex

mixture be analyzed

by GC?


http://www.restek.com/chromatogram/view/GC_EV00640

Challenges of GC Analysis

• Data Overload

• How can treatment plant operators receive the maximum impact from continuous data?

• Can GC analysis of VOCs be automated?


Drinking Water at the Panama Canal

• Man-made, 77 km

passageway

• Connects Atlantic and

Pacific Oceans

• Highly trafficked

8/16/2017 7

http://www.shutterstock.com/

Autonomous, Real Time Detection of 58 VOCs in the Panama Canal


• Potential for release of

volatile organic

compounds (VOCs)

• Fuel

• Cargo

• Liquid chemicals

• Oil/gas

8/16/2017 8

http://maritime-connector.com/wiki/panamax/



• Three water treatment

plants

• >100 million gallons of

water daily

• Miraflores (50 MGD)

and Mendoza (40 MGD)

on the Pacific

• Mount Hope (35MGD) on

the Atlantic

• CMS5000 installed at the

Miraflores Filtration Plant

8/16/2017 9

http://www.thepanamadigest.com



• Miraflores is the largest

treatment plant on the

Panama Canal

• 40% of drinking water for

Panama City is

processed by the

Miraflores Filtration Plant

• Automated testing of

VOCs will help the water

utility to ensure public

safety

8/16/2017 10

Water Intake at Miraflores Treatment Plant


8/16/2017

Automatic Testing of VOCs

• CMS5000

• Autonomous testing

• In-house screening

• Less wasted time and money

Autonomous, Real Time Detection of 58 VOCs in the Panama Canal 11

8/16/2017 12


• Water samples are continuously pumped through the sampling chamber

• VOCs are extracted from water using purge and trap technology

• Argon gas bubbles through the water sample

• A portion of the VOCs will pass from the water phase to the gas phase and collect in the “headspace” at the top of the sample collection tube

• The sample is collected from the headspace


8/16/2017


• VOCs are

loaded onto a

Tri-Bed

concentrator

• The sample is

then desorbed

onto the GC

column

• Detection by a

Micro Argon

Ionization

Detector

(MAID)


8/16/2017


• Nickel-63 radioactive source (Ni63)

• Ionizes the argon gas by emitting beta particles

• Detection Capabilities

• VOCs with ionization potentials (IP) < 11.7 eV

• Boiling point up to 250 °C

• PPT detection limit for most compounds

• 0.5 ppb – 1 ppm


8/16/2017

Panama Canal

• Requires the automated monitoring of

several USEPA 8260B compounds

• Compounds must be detected to 1 ppb

• SCADA system integration

• Ability to analysis calibration check

standards

• Generation of alarms


58 Compounds

8/16/2017 16

vinyl chloride chloroformtrans-1,3-

dichloropropenebromoform 4-isopropyltoluene

bromomethane 2,2-dichloropropane 1,1,2-trichloroethane styrene 1,3-dichlorobenzene

chloroethane 1,2-dichloroethane toluene o-xylene 1,4-dichlorobenzene

trichloro-

fluoromethane1,1,1-trichloroethane 1,3-dichloropropane

1,1,2,2-

tetrachloroethanesec-butylbenzene

1,1-dichloroethene 1,1-dichloropropenedibromo-

chloromethane1,2,3-trichloropropane tert-butylbenzene

methylene chloride benzene 1,2-dibromoethane isopropylbenzene 1,2-dichlorobenzene

trans-1,2-

dichloroethenecarbon tetrachloride tetrachloroethene bromobenzene n-butylbenzene

1,1-dichloroethane dibromomethane1,1,1,2-

tetrachloroethane2-chlorotoluene

1,2,4-

trichlorobenzene

MTBE 1,2-dichloropropane chlorobenzene 4-chlorotoluene naphthalene

cis-1,2-dichloroethenebromodichloromethan

eethylbenzene n-propylbenzene

1,2,3-

trichlorobenzene

bromo-chloromethane trichloroethene m-xylene1,3,5-

trimethylbenzenehexachloro-butadiene

cis-1,3-

dichloropropenep-xylene

1,2,4-

trimethylbenzene


8/16/2017

Panama Canal

Challenge: Develop an analytical method

that will autonomously detect and quantify 58

VOCs by GC

Proposal: Use two GC systems with complementary column phases run in tandem.


Analysis of VOCs

8/16/2017 18

• Two GCs with different columns

DB-1 (100% PDMS, non-polar) DB-624 (94% PDMS, 4%

Cyanopropylphenyl, slightly polar)


Analysis of VOCs

8/16/2017 19

• Each column separates

different compounds

• Water is automatically sampled

• Attachment to the plumbing

system to allow for standard

spikes


CMS5000 installed at the Panama Canal

GC Method

• Calibration 1-10 ppb

• 51 minute method

• 15 minute isothermal hold time at 45 °C, followed by slow ramp

• Separation of early eluting compounds

• Calibration stable over 4-6 months

8/16/2017 20Autonomous, Real Time Detection of 58 VOCs in the Panama Canal

1

2

4

5, 6

7

8,9 10

11

14

15

1617

18

19,20

21, 22

24

25

26,27

28 29

30

31, 32

33

34, 35, 36

37

38, 39

40

41

23

43

44, 45

46

47, 48

49

50

5152

53

54

55

56

57

58

423

12, 13

Analysis of VOCs

DB-1, 1 ppb standard


1

3

4

5

6

10,

13

1112

15

16, 18

14,

17

22

20

1921

23

26

24, 25

30

27

2829

32

31,

33

34, 35

38 37

36

41

39, 40, 43,

45

44

46

48

47

51

49

52

50, 53

54

55

58,

56

57

42

2

7,9

8

Analysis of VOCs

DB-624, 1 ppb standard


Coelutions

• Coelution: Two or more chemical compounds elute from a column at

the same time, making separation and identification difficult

8/16/2017 23

• With MS coeluting compounds

can be separated using ion

profiles

• In GC analysis coeluting

compounds cannot be

separately quantified


Coelutions on DB-1

8/16/2017 24



bromomethane2,2-

dichloropropane

1,1,2-

trichloroethanestyrene

1,3-

dichlorobenzene

chloroethane 1,2-dichloroethane toluene o-xylene1,4-

dichlorobenzene

trichloro-

fluoromethane

1,1,1-

trichloroethane

1,3-

dichloropropane

1,1,2,2-


1,1-dichloroethene1,1-

dichloropropene

dibromo-

chloromethane

1,2,3-

trichloropropanetert-butylbenzene

methylene chloride benzene 1,2-dibromoethane isopropylbenzene1,2-

dichlorobenzene

trans-1,2-

dichloroethene

carbon

tetrachloridetetrachloroethene bromobenzene n-butylbenzene



1,2,4-

trichlorobenzene

MTBE1,2-

dichloropropanechlorobenzene 4-chlorotoluene naphthalene

cis-1,2-

dichloroethene

bromodichlorometh

aneethylbenzene n-propylbenzene

1,2,3-

trichlorobenzene

bromo-

chloromethanetrichloroethene m-xylene

1,3,5-

trimethylbenzene

hexachloro-

butadiene

cis-1,3-


1,2,4-

trimethylbenzene

Coelutions on DB-624

8/16/2017 25



bromomethane2,2-

dichloropropane

1,1,2-

trichloroethanestyrene

1,3-

dichlorobenzene

chloroethane 1,2-dichloroethane toluene o-xylene1,4-

dichlorobenzene

trichloro-

fluoromethane

1,1,1-

trichloroethane

1,3-

dichloropropane

1,1,2,2-


1,1-dichloroethene1,1-

dichloropropene

dibromo-

chloromethane

1,2,3-

trichloropropanetert-butylbenzene

methylene chloride benzene 1,2-dibromoethane isopropylbenzene1,2-

dichlorobenzene

trans-1,2-

dichloroethene

carbon

tetrachloridetetrachloroethene bromobenzene n-butylbenzene



1,2,4-

trichlorobenzene

MTBE1,2-

dichloropropanechlorobenzene 4-chlorotoluene naphthalene

cis-1,2-

dichloroethene

bromodichlorometh

aneethylbenzene n-propylbenzene

1,2,3-

trichlorobenzene

bromo-

chloromethanetrichloroethene m-xylene

1,3,5-

trimethylbenzene

hexachloro-

butadiene

cis-1,3-


1,2,4-

trimethylbenzene

Analysis of VOCs

• If a compound coelutes on one column but not the other, it can be

quantified

• If a compound coelutes on both columns it cannot be quantified by

the software

• Five compounds coelute on both columns

• MTBE

• 2,2-dichloropropane

• n-propylbenzene

• 1,1,1,2-tetrachloroethane

• 1,1,2,2-tetrachloroethane


Analysis of VOCs

• Calculate the concentration manually by subtraction

• Example: MTBE

8/16/2017 27

Conc. 1,1-DCE/MTBE, Column 1 – Conc. 1,1-DCE, Column 2 =

Conc. MTBE

Conc. trans-1,2-DCE/MTBE, Column 2 –

Conc. trans-1,2-DCE, Column 1 = Conc. MTBE


Analysis of VOCs

• System alarms when concentrations over 2 ppb are detected


Conclusions

• Two GC systems with purge and trap working in tandem

• Long term, automated detection of VOCs in water of the Panama

Canal

8/16/2017 29

https://priceonomics.com

• Ensure the water

in the Panama

Canal can be

used for both

transport and

drinking water



Documents

AUTONOMOUS, REAL TIME DETECTION OF 58 VOCS IN …apps.nelac-institute.org/nemc/2017/docs/pdf/Monday-Changing the... · • Long term, automated detection of VOCs in water of the Panama