Assessment of Geosmin Occurrence and Potential Treatment by Advanced Oxidation

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1 Assessment of Geosmin Occurrence and Potential Treatment by Advanced Oxidation Sean MacIsaac, Elliott Wright & Dr. Graham Gagnon Civil and Resource Engineering Dalhousie University

2 Overview Background Pockwock Lake Taste and Odor Compounds Objectives Geosmin Occurrence Advanced Oxidation Processes (AOP) Experimental Setup HRM Source Waters Parameters Equipment Results Geosmin Occurrence Residual Geosmin FEEM Pockwock post-filter plots PARAFAC Pockwock post-filter Conclusion Acknowledgments

3 Background- Pockwock Lake

4 Background- Pockwock Lake Pockwock Lake: Low DOC High Colour Low Turbidity

5 Background- Pockwock Lake Pockwock Lake: Low DOC High Colour Low Turbidity

6 Background- Pockwock Lake 40 km Pockwock Lake: Low DOC High Colour Low Turbidity

7 Background- Taste and Odor Compounds Geosmin MIB Heptanal Indole Linolenic acid

8 Background- Taste and Odor Compounds Geosmin MIB Heptanal Indole Linolenic acid Algae metabolites Decomposing organic material Anthropogenic origin

9 Background- Taste and Odor Compounds Geosmin MIB Heptanal Indole Linolenic acid

10 Background- Taste and Odor Compounds Geosmin Taste and odor compound Metabolite of certain blue green algae species Musty, dirt like smell Detection limit of 3ng/L

11 Objectives- Geosmin Occurrence Geosmin was first detected in the Halifax Regional Municipality (HRM) in the fall of 2012 Numerous customer complaints about off tasting water Concentrations of geosmin are low when compared to other utilities who encounter this issue

12 Objectives- Geosmin Occurrence Geosmin occurrence survey within HRM Development of an analytical method to detect geosmin at low concentrations

13 Objectives- Advanced Oxidation Processes Advance oxidation processes (AOP) UV UV/H 2 O 2 UV/O 3 O 3 OH production Target chemical degradation

14 Experimental Setup- Water Survey Location Treatment Type Production Construction Date Pockwock Lake Lake Major Direct Dual Media Filtration Sedimentation Multi Media Filtration 100 MLD MLD 1999 Middle Musquodoboit Membrane Filtration 60 m 3 /D 2010 Collins Park Membrane Filtration 73 m 3 /D 2010 Bomont Membrane Filtration 15 m 3 /D 2012 Lake Lemont Emergency Supply Lake Major NA NA Chain Lake Emergency Supply Pockwock NA NA

15 Experimental Setup- Pockwock Pockwock Lake Raw water Plant filtered water AOP UV AOP Low High O 3 1 mg/l 10 mg/l H 2 O 2 1 mg/l 10 mg/l UV 100 mj/cm mj/cm 2 UV/H 2 O 2 UV/O 3 20 ng/l known geosmin spike

16 Experimental Setup- Parameters Pockwock Raw Pockwock Post Filter TOC DOC UV 254 Fluorescent Excitation Emission Matrix (FEEM) GC MS (Geosmin) HPLC

Fluorescent Excitation Emission Matrix (FEEM) Horiba Aqualog FEEM λ ex range 240-600 nm

17 Fluorescent Excitation Emission Matrix (FEEM) Horiba Aqualog FEEM λ ex range nm λ em range nm 10 second integration time 3 nm increment (Horiba Scientific, 2014)

18 Fluorescent Excitation Emission Matrix (FEEM) 3D analysis Difficult to get quantitative data from plots We can see something is happening but analysis remains unclear PARAFAC analysis 2D analysis Easier data to manage Select data by picking specific excitation wavelengths in 3D plot and slicing it into a 2D graph

19 Gas Chromatography- Mass Spectrometry (GC-MS)

20 HRM Geosmin Survey Location Sampling Date Geosmin ng/l Pockwock Lake Oct 10/ Lake Major Oct 22/13 <Detection Limit Middle Musquodoboit Oct 23/ Collins Park Oct 23/ Bomont Oct 30/ Lake Lemont Oct 28/ Chain Lake Sept 20/13 <Detection Limit

21 Raw Water + Geosmin (20 ng/l) 140% 120% Percent Remaining 100% 80% 60% 40% 20% 0% UV Lo Hi Lo Hi Lo Hi Lo Hi Lo Hi H 2 O 2 Lo Lo Hi Hi O 3 Lo Lo Hi Hi

22 Raw Water + Geosmin (20 ng/l) 140% 120% Percent Remaining 100% 80% 60% 40% 23% 20% 0% UV Lo Hi Lo Hi Lo Hi Lo Hi Lo Hi H 2 O 2 Lo Lo Hi Hi O 3 Lo Lo Hi Hi

23 Post-Filter Water- Residual Geosmin (20ng/L) 120% 100% Percent Remaining 80% 60% 40% 102% 78% 88% 20% 31% 53% 1% 0% UV Lo Hi Lo Hi Lo Hi H 2 O 2 Lo Lo Hi Hi

24 Post-Filter Water- Residual Geosmin (20ng/L) 120% 100% Percent Remaining 80% 60% 40% 102% 78% 88% 20% 31% 53% 1% 0% UV Lo Hi Lo Hi Lo Hi H 2 O 2 Lo Lo Hi Hi

25 Post-Filter Water- Residual Geosmin (20ng/L) 120% 100% Percent Remaining 80% 60% 40% 20% 102% 78% 69% 54% 40% 27% 0% UV Lo Hi Lo Hi Lo Hi O 3 Lo Lo Hi Hi

26 Post-Filter Water- Residual Geosmin (20ng/L) 120% 100% Percent Remaining 80% 60% 40% 20% 102% 78% 69% 54% 40% 27% 0% UV Lo Hi Lo Hi Lo Hi O 3 Lo Lo Hi Hi

27 Plant Filtered Water- SUVA SUVA (L/mg M)

28 Plant Filtered Water- SUVA SUVA (L/mg M)

29 Regional Integration- Pockwock Post-Filter Water Regional integration technique Integrates regions of a FEEM contour plot Humic regions Protein regions Indicates changes in fluorescent NOM

30 Untreated Raw: Pockwock UF - F Post Filter emission wavelength (nm) Protein Humic Raman Units excitation wavelength (nm) 0

31 Regional Integration- Pockwock Post-Filter Water 120% Humic Region 100% Percent Remaining 80% 60% 40% 20% 0% UV Low UV High UV Low H2O2 Low UV High H2O2 Low UV Low H2O2 High UV High H2O2 High UV Low O3 Low UV High O3 Low UV Low O3 High UV High O3 High

32 Regional Integration- Pockwock Post-Filter Water 120% Humic Region 100% Percent Remaining 80% 60% 40% 44% 50% 20% 0% UV Low UV High UV Low H2O2 Low UV High H2O2 Low UV Low H2O2 High UV High H2O2 High UV Low O3 Low UV High O3 Low UV Low O3 High UV High O3 High

33 Regional Integration- Pockwock Post-Filter Water 140% Protein Region 120% 100% Percent Remaining 80% 60% 40% 20% 0% UV Low UV High UV Low H2O2 Low UV High H2O2 Low UV Low H2O2 High UV High H2O2 High UV Low O3 Low UV High O3 Low UV Low O3 High UV High O3 High

34 Regional Integration- Pockwock Post-Filter Water 140% Protein Region 120% Percent Remaining 100% 80% 60% 40% 41% 20% 0% UV Low UV High UV Low H2O2 Low UV High H2O2 Low UV Low H2O2 High UV High H2O2 High UV Low O3 Low UV High O3 Low UV Low O3 High UV High O3 High

35 Parallel Factor Analysis (PARAFAC) Analyze FEEM samples using DomFluor v1.7 Matlab Toolbox Determines unique components in a water matrix using parallel factor analysis in Matlab Breaks 3D data into 2D excitation and emission plots Validates the generated model via split half analysis

36 PARAFAC- Pockwock Post-Filter Water Humic like I Intensity Ex Comp1 Em Comp Wavelength (nm)

37 PARAFAC- Pockwock Post-Filter Water Humic like II Intensity Ex Comp2 Em Comp Wavelength (nm)

38 PARAFAC- Pockwock Post-Filter Water Humic like III Intensity Ex Comp3 Em Comp Wavelength (nm)

39 PARAFAC- Pockwock Post-Filter Water Protein like 0.2 Intensity Ex Comp4 Em Comp Wavelength (nm)

40 PARAFAC- Pockwock Post-Filter Water Component Ex Range (nm) Em Range (nm) Description Humic like substance , Humic like substance , Humic like substance , Proteinaceous region associated with tryptophan

41 Untreated Raw: Pockwock UF - F Post Filter emission wavelength (nm) Protein Humic Raman Units excitation wavelength (nm) 0

42 Conclusion The HRM geosmin survey indicated that geosmin is present in a number of other source-waters in the municipality Water treatment plants using traditional treatments are not effective at removing geosmin Membrane plants are much more successful at addressing the taste and odor issue Bench-scale studies indicated that AOP is a potential tool for treating for geosmin High UV and high H 2 O 2 treatments were the best performing in both raw and post-filter water experiments O 3 scavenges other portions of NOM before attacking and degrading geosmin UV alone is ineffective at removing geosmin NOM fluorescence model indicates humic material is the main contributor to FEEM NOM Regional integration indicates that O 3 is removing a large portion of this humic region

43 Future Work Continue to monitor and measure geosmin as it persists in source waters in HRM Refine NOM models for Pockwock water Investigate additional interactions between NOM as it changes after undergoing AOP

44 Acknowledgements Halifax Water NSERC Dr. Graham Gagnon Elliott Wright CWRS

45 Questions?

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