introduction objectives methodology...uv-radiation chloramines (nh 2 cl) chlorine dioxide (clo 2) 3...

Occurrence and variability of ozonation disinfection by-products during water

treatment and distributionOlivier Laflamme, Sabrina Simard, Christelle Legay,

Caetano Dorea, Manuel RodriguezUniversité Laval

WQTC 2017 - 2017-11-14

Introduction

• Introduction •Objectives •Methodology •Results •Conclusion

2

Disinfection

• Chlorine 1) Sodium hypochlorite solutions (NaOCl)2) Gas (Cl2)

Ozone (O3) UV-radiation Chloramines (NH2Cl) Chlorine dioxide (ClO2)

3

Primarily, the choice of disinfectant(s) depends

on the quality of the water source, the

residual, the adverse effect and the $$$!

Disinfection

4

ADVANTAGES

DISADVANTAGES

• Chlorine 1) Sodium hypochlorite solutions (NaOCl)2) Gas (Cl2)

Ozone (O3) UV-radiation Chloramines (NH2Cl) Chlorine dioxide (ClO2)

Ozone

• The use of ozone (O3) has increased rapidly due to a better inactivation/diminution of : 1,2

Pathogenic micro-organisms (Cryptosporidium, Giardia, others…)

Natural Organic Matter (NOM) Iron (Fe) and Manganese (Mn) Taste and Odors Pesticides Trihalomethanes (THMs) and haloacetic acids

(HAAs) in finished water

51: Legube, B. The Handbook of Environmental Chemistry, 2003.2: WHO - Guidelines for Drinking-water Quality, 2008.

ADVANTAGES

• Ozone leaves no residual in the treated water• And …

O3 + NOM OBPs

6

ORGANIC INORGANIC

Halogenated aldehydes (HAL)

Bromate

Non-Hal. aldehydes (NON-HAL)

3: U.S. Environmental Protection Agency, Office of Air and Radiation, 1989.

Ozone DISADVANTAGES

(10 µg/L) Ø regulations

Ø regulations Probable or proven human

carcinogen under conditions of unusually high or prolonged

exposure3

HAL & NON-HAL

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HAL NON-HALChloroacetaldehyde (CAL) Formaldehyde

Dichloroacetaldehyde (DCAL) AcetaldehydeBromochloroacetaldehyde (BCAL) Propionaldehyde

Dibromoacetaldehyde (DBAL) ButyraldehydeBromodichloroacetaldehyde (BDCAL) ValeraldehydeDibromochloroacetaldehyde (DBCAL) Hexanal

Tribromoacetaldehyde (TBAL) BenzaldehydeGlyoxal

Methylglyoxal

Objectives

• Introduction •Objectives •Methodology •Results•Conclusion

8

Objectives

1. Identify and quantify OBPs in municipal drinking water (with facilities using ozonation)

2. Improve the understanding of formation of OBPs during drinking water production and distribution

3. Characterize their spatio-temporal variability and identify the factors responsible for these variations

9

Methodology

• Introduction •Objectives•Methodology•Results•Conclusion

10

Methodology

• Two Canadian facilities partners of the ULavalDrinking Water Chair

Choice of treatment facility Using at least one step of liquid chlorination Using at least one step of ozonation

Rechlorination reservoirs (Distribution system) Distribution network with rechlorination Easily accessible for sampling

11

Methodology

1. North Shore of Quebec City

2. South Shore of Quebec City

• Full-scale study carried out for 12 months monthly monitoring (Nov. 2016 – Sept. 2017)

12

Where is Quebec City?

13

Methodology

14

1st system 2nd system

First facility

15

Population served : 125 000

1st facility

St-L

awre

nce

Rive

r

Second facility

16

Population served : 53 200

2nd facility

Chau

dièr

e Ri

ver

Results

• Introduction •Objectives•Methodology•Results•Conclusion

17

Characterization

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Facility Raw Finished water Network

Bromide – Br –(µg/L)

1st 21.5 - -

2nd 6.4 - -

TOC(mg/L)

1st 4.53 2.18 2.14

2nd 7.93 2.59 2.57

UV (254nm) (cm-1)

1st 0.160 0.024 0.023

2nd 0.395 0.030 0.029

pH1st 7.9 7.6 7.7

2nd 7.7 7.6 7.7

Results are averages of n = 12

Ozone – dose

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Facility Pre-O3 Inter-O3 Post-O3

O3 dosage(mg/L)

1st 0.76 - 0.62nd - - 1.21

Results are annual averages

Spatio-temporal variability

20

BROMATE n = 12

1 2 3 4

1st FACILITY 2nd FACILITY

BrO

3- (µg/

L)

21

Spatio-temporal variabilityHAL n = 12

1st FACILITY 2nd FACILITY

1 2 3 4

SUM

_HAL

(µg/

L)

Spatio-temporal variabilityNON-HAL n = 12

221 2 3 4

1st FACILITY 2nd FACILITY

Presence pattern:

FormALAcetALGlyoxal

PropionALButyrAL

Methylglyoxal

SUM

_NO

N-H

AL(µ

g/L)

Comparison – NON-HAL

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Quebec, 2017 n = 12

Quebec, 2017 n = 12

China, 2017 5

n = 9

USA, 2008 4

n = 1

Formal-dehyde 6.7 18.3 ≈ 10-15 34.3

Acetal-dehyde 3.1 5.8 ≈ 25-35 12.6

Disinfection O3/Cl2 O3/Cl2 O3/Cl2 O3/Cl2

1st FACILITY 2nd FACILITY

4 : Miltner et al., 2008.5 : Zhong et al., 2017.

* Results = Mean values at TW

Treated waterFULL SCALE PILOT SCALE

• Occurrence of NON-HAL in Quebec is lower or equivalent versus other countries at treated water

Seasonal pattern

24

Results are averages

1ST FACILITY

SeasonBrO3

-

(µg/L)HAL

(µg/L)NON-HAL

(µg/L)TW Network TW Network TW Network

Winter (Dec-Mar)

<LOD <LOD 0.1 0.1 11.2 8.7

Spring (Apr-May)

<LOD <LOD <LOD <LOD 17.4 21.5

Summer(Jun-Aug)

1.6 1.8 <LOD 0.9 23.8 22.0

Fall(Sep-Nov)

<LOD 0.5 <LOD <LOD 10.2 12.7

* TW = treated water

• T° has an impact on OBPs [ ] • Important fact : FormAL > AcetAL in Wint., but AcetAL > FormAL

in Spr. (!)

Seasonal pattern

• Different pattern versus the 1st facility for NON-HAL formaldehyde responsible for the drop in Summer

• T°, ozone dose and biodegradability have an impact on OBPs [ ] 25

Results are averages

2nd FACILITY

SeasonBrO3

-

(µg/L)HAL

(µg/L)NON-HAL

(µg/L)TW Network TW Network TW Network

Winter (Dec-Mar)

1.3 0.3 <LOD <LOD 23.8 27.1

Spring (Apr-May)

<LOD <LOD <LOD <LOD 42.9 35.2

Summer(Jun-Aug)

4.7 2.1 0.5 <LOD 42.6 15.8

Fall(Sep-Nov)

<LOD <LOD <LOD <LOD MD MD

* TW = treated water

Conclusion

• Introduction •Objectives•Methodology •Results•Conclusion

26

Summary

• Bromate is under the standard (10 µg/L), except in one sample (collected at the treatment plant)

• Bromate has a different occurrence and variabilitydepending on the facility

• Ozone is responsible on forming bromate, but hypochlorite solutions probably also contribute

• Greater presence in Summer than in Winter: Impact of temperature

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BROMATE

Summary

• Few results above the limit of detection (LOD) Highest result : 2.8 µg/L for TBAL

• Presence of HAL < NON-HAL

• HALs have a different occurrence and variabilitydepending on the facility

• Occurrence of HALs tends to be lower in the systems under study in comparison to other studies (full-scale) 4,6

28

HAL

4 : Miltner et al., 2008. USA6 : Legay et al., 2015. CANADA

Summary

• NON-HALs have a different occurrence and variabilitydepending on the facility ; nearly x2 for 2nd facility vs 1st

• Presence of NON-HAL > HAL

• Formaldehyde and acetaldehyde = more abundant Occurrence of NON-HALs lower/equivalent in comparison to

other studies (full-scale or pilot-scale)

• Formation/degradation mechanism still not well understood … but it’s biodegradable

• Greater presence in Summer than in Winter ; ozone and chlorine dose and temperature have an impact

29

NON-HAL

• Finishing data analysis

• With the occurrence and variability of OBPs, try to understand their formation/degradation impact of hypochlorite solutions on

bromate and NON-HAL biodegradability of organic-OBPs

30

Future work

• To our knowledge, in the literature, this is one of the first Canadian full-scale study regarding spatio-temporal occurrence of NON-HALs in municipal drinking water

• Data will help operators to improve the treatment and operations (in the treatment plant and in the distribution system)

• Results of this study could be used to support future regulations for the organic-OBPs

31

Conclusion

THANKS!!!

• The Quebec Ministère du Développement Durable, Environnementet Lutte contre les Changements Climatiques (MDDELCC) => Isabel Parent, Anouka Bolduc and Jean-Luc Pilote

• Drinking Water Chair, Laval University => Jessica Beaupré, Pamela Ouellet, Antoine Grondin, Émilie Leclerc, Vincent Boutet and Sabrina Simard

• WQTC for the opportunity to present my results

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REFERENCES

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1: Legube, B. The Handbook of Environmental Chemistry Vol. 5, Part G 2003: p. 95-116.2: WHO - Guidelines for Drinking-water Quality, THIRD EDITION, Volume 1-Recommendations, 2008.3: U.S. Environmental Protection Agency, Office of Air and Radiation. Report to Congress on Indoor Air Quality, Volume II: Assessment and Control of Indoor Air Pollution, 1989.4: Miltner et al. / Journal of Toxicology and Environmental Health, Part A, 71:17, 2008, 1133-1148.5: Zhong et al. / Chemosphere, 179, 2017, 290-297.6: Legay et al. / ACS Symposium Series, 1190, 2015, 341-362.7: Health Canada, Guidelines for Canadian Drinking Water Quality: Guideline Technical Document – Formaldehyde, 2003.

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Questions ?

•EXTRA STUFF … IN CASE

35

Seasonal pattern

• Temperature has an impact on OBPs [ ] • Important fact : FormAL > AcetAL in Wint., but AcetAL > FormAL in Spr. (!) 36

Season

Winter (Dec-Mar)

Spring (Apr-May)

Summer(Jun-Aug)

Fall(Sep-Nov)

BrO3- HAL NON-HAL

0.3 0 27.1

0 0 35.2

2.1 0 15.8

0.4 0 MD

BrO3- HAL NON-HAL

1.3 0 23.8

0 0 42.9

4.7 0.5 42.6

0 0 MD

TREATED WATER DISTRIBUTION NETWORK

Results are averages

2ND FACILITY

Seasonal pattern

• Temperature has an impact on OBPs [ ] • Important fact : FormAL > AcetAL in Wint., but AcetAL > FormAL in Spr. (!) 37

Results are averages

2nd FACILITY

Season BrO3- HAL NON-HAL

FW Network FW Network FW Network

Winter (Dec-Mar)

Spring (Apr-May)

Summer(Jun-Aug)

Fall(Sep-Nov)

* FW = finished water

Seasonal pattern

• Temperature has an impact on OBPs [ ] • Important fact : FormAL > AcetAL in Wint., but AcetAL > FormAL in Spr. (!) 38

Season

Winter (Dec-Mar)

Spring (Apr-May)

Summer(Jun-Aug)

Fall(Sep-Nov)

BrO3- HAL NON-HAL

0 0.1 7.9

0 0 18.3

1.8 0.6 22.0

0.5 0 5.8

BrO3- HAL NON-HAL

0 0.2 11.2

0 0 17.4

1.6 0.7 23.8

0 0 6.5

Results are averages

1ST FACILITY TREATED WATER DISTRIBUTION NETWORK