Responding to the Challenge of Harmful algal blooms in Source Water

Transcription

1 Responding to the Challenge of Harmful algal blooms in Source Water Arash Zamyadi, NSERC Postdoctoral Fellow, University of Toronto, CANADA Prof. Michèle Prévost and Dr. Sarah Droner, École Polytechnique de Montréal, CANADA Great Lakes, Great Challenges Forum IJC & Oakland University March 14, 2013 Donald Ellis, Anouka Bolduc, Christian Bastien, MDDEFP (Quebec MOE), CANADA Prof. Ron Hofmann, University of Toronto, CANADA 1

2 Problems associated with Harmful Algal Blooms (HABs) Release of T&O (ng/l) and toxins (µg/l) Release of organic material with important demand of reactive (e.g. PAC & coagulant) and oxidants, and disinfection by-products (DBP) formation potential Interruption of treatment train, breakthrough of cells, T&O compounds, toxins and other water born pathogens

3 Toxins (µg/l) Toxins (µg/l) Breakthrough of cyanotoxins in a drinking water treatment plant - Québec (Canada), 2010 Water samples Total:

4 South Australian solution: «SA Water River Murray Drought Response Field Team» : Equipped with in vivo YSI multi-probe On the boat (in vivo!!!) microscopic speciation and enumeration capacity Closure of the DWTP intakes based on the bloom movement on the water body Dr. Thorsten Mosisch, SA Water RDI WORKSHOP, Adelaide University, South Australia

5 Summary of issues involved with presence of HABs in drinking water sources and objectives Presence of HABs and their associated toxin in water intake of DWTP (e.g. in Lake Erie) Need for fast treatment adjustment Fast HAB detection Microscopic enumeration: Time consuming Solution: Application of the in vivo probes for treatment adjustment How to use the probe? Obj. How to adapt the technical solutions to site specific needs?

6 Coagulants Treatment processes in the studied drinking water treatment plants (DWTP) Lake or river DWTP #1 & #2: without preozonation but with PAC Chlorine DWTP #3: with preozonation, but without PAC Reservoir Floculation & clarification Filter: sand & anthracite Distribution

7 Monitoring Strategy in the studied drinking water treatment plant (DWTP) Continuous monitoring using YSI multiprobe at raw water, water on the surface of the clarifiers, clarified water, filtered water, and treated water. Sampling per bloom events: Up to 5 consecutive days during bloom events WATER: raw, clarified, filtered & treated SCUM & SLUDGE: surface of sedimentation and filtration basins; sludge bed and concentrated sludge from the sedimentation tank.

8 Over 9 Commercially available probes: Which probe to use? Excitation wavelengths Emission wavelength Commercial probe for in situ measurement Green: 525 nm CB: 570 nm Crypto: 590 nm Diatom: 610nm 690 nm bbe, FluroProbe CB: 620nm 655 nm TriOS, miroflu-blue CB: 590 ( ) nm 660 ( ) nm YSI, 6131 BGA-PC Chla: 470 nm 680 nm YSI, CHLa

9 Breakthrough of cyanobacteria inside the DWTP#1 July 12 July 12 July 12 July 12 Noon Midnight Midnight Midnight Surface of the source Raw water turbidity inside the plant: 11.5 NTU Surface of the flash mix Raw water turbidity inside the plant: 42.5 NTU Surface of the sedimentation basin Normal turbidity of clarified water: NTU Surface of the filtration basin Normal turbidity of filtered water: NTU Turbidity of clarified water: 2.3 NTU Turbidity of filtered water: NTU

10 Breakthrough of cyanobacteria inside the DWTP#1 In vivo measurements inside the sedimentation basin

11 In vivo measurements with the YSI probe (Ratio Fluorescence Unit - RFU) In vivo measurements with the YSI probe at the DWTP# No treatment adjustment using probe in vivo readings Treatment adjustment using probe in vivo readings EB Raw water ED Clarified water EFiltered water ETreated water

12 Cells/mL EB (Cellules/mL) Breakthrough of cyanobacteria inside the DWTP#1 100,000 80,000 Cell numbers 60,000 in raw water 40,000 Anabaena sp. Anabaena Aphanizomenon sp. Aphanizomenon Microcystis sp. Microcystis Pseudanabaena sp. Pseudanabaena Total Total ,000, , , , ,000 0 WHO 100k Qc 20k Qc 10k WHO 2k

13 Cells/mL EB (Cellules/mL) Cell numbers in filtered water 60,000 10,000 Breakthrough of cyanobacteria inside the DWTP#1 100,000 80,000 40,000 20,000 Anabaena sp. Anabaena Aphanizomenon sp. Aphanizomenon Microcystis sp. Microcystis Pseudanabaena sp. Pseudanabaena Total 1,

14 Anabaena Aphanizomenon Microcystis Pseudanabaena Anabaena Aphanizomenon Microcystis Pseudanabaena DWTP #1 Percentage & log removal of cyanobacterial cells by treatment processes 14/07/2011 Aphanizomenon dominant 24/08/2011 Microcystis dominant Treatment Clarifier (3) 54.2 (<1) 99.7 (2) 99.6 (2) (3) 73.4 (<1) 99.8 (2) 99 (2) Filter 100* 85.6 (<1) (1) Chlorine (<1)

15 For detailed information on this project:

16 In vivo measurements with YSI probe (Ratio Fluorescence Unit - RFU) DWTP #2 (Low risk!!!) In vivo measurements with YSI probe August September October November EB Raw water ED Clarified water EFiltered water ETreated water

17 Cellules/mL Cells/mL Breakthrough of cyanobacteria inside the DWTP#2 Number of accumulated cells in the sludge bed of clarifiers without pre-ozonation 100,000 10,000 1, Anabaena Microcystis Oscillatoria Total Aphanizomenon Pseudanabaena Lyngbya

18 In vivo measurements with YSI probe (Ratio Fluorescence Unit - RFU) DWTP#3 In vivo measurements with YSI probe August September October Nov. EB Raw water ED Clarified water EFiltered water ETreated water

19 Cellules/mL Cells/mL Breakthrough of cyanobacteria inside the DWTP#3 Number of accumulated cells in the sludge bed of clarifiers with pre-ozonation Anabaena Microcystis Oscillatoria Aphanizomenon Pseudanabaena Total

20 L. A. Coral, A. Zamyadi, B. Barbeau, F. J. Bassetti, F. R. Lapolli & M. Prévost (2013 Inpress) Oxidation of M. aeruginosa and A. flos-aquae by ozone: impacts on cell integrity and chlorination by-product formation. Water Research. M. aeruginosa A. flos-aquae Before O 3 After O 3 Before O 3 After O 3

21 Conclusions Cyanobacteria and cyanotoxins enter the DWTPs and are relatively well removed by the treatment however they can breakthrough into the treated water Extreme concentrations of cyanobacteria can enter the plant for extended periods (> 24 hours) Cyanobacterial variation at the raw water can be very fast (factor of 100X in less than 24 h): require real-time measurements In vivo detections of cyanobacteria using PC and Chla probes allow operators to adjust the treatment based on monitoring of the breakthrough of cell into the plant The cyanobacteria disrupt treatment processes at the point where the filter is no longer effective in removing turbidity and filtered water does not meet the regulatory obligations

22 Conclusions Present species in water have an impact on the performance of the coagulation and sedimentation The probe is not able to distinguish the species or to choose the best type of coagulant in function of species Cyanobacteria and their toxins accumulate in the sludge bed and form scums above clarifiers and filters The probes are ideal tool for cyanobacteria monitoring at the water intake, in the water near the water intake and inside the treatment plant Immediate cell membrane damage due to direct ozonation of cells

23 Ongoing Projects In vivo HAB monitoring at the water intake of a DWTP located on Lake Erie (Ontario, Canada) Co-supervising with Prof. Sarah Dorner (Project Leader), funded by Canadian Water Network (CWN) and Union Water Development of advanced treatment barriers for removal of cyanotoxins and T&O compounds Pilot set-up within a DWTP located on Lake Ontario (Ontario, Canada) DWRG at University of Toronto and Region of Peel (Ontario)

24 Acknowledgments NSERC Industrial Chair on Drinking Water at École Polytechnique de Montréal, Canada Prof. Sebastian Sauvé, Université de Montréal, Canada Prof. David F. Bird, Université du Québec a Montréal (UQAM), Canada MDDEFP (Quebec MOE) Service des Eaux Municipales et Région Estrie, Canada MDDEFP (Quebec MOE) Centre d`expertise en analyses environnementales du Québec, Canada The studied DWTPs in Québec, Canada Fonds de recherche - nature et technologies du Québec, Canada Natural Sciences and Engineering Research Council (NSERC) of Canada Australian Water Quality Centre (AWQC), Australia and particularly Dr. Gayle Newcombe DWRG, Univeristy of Toronto, Canada YSI Inc., USA and particularly Rob Ellison

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26 Responding to the HAB challenge in the North American drinking water sources: Management guideline and regulation are provided by water authorities BUT Are the guide recommendations applicable to your operational Les recommandations sont-elles applicables à votre usine conditions? Did the guide help you to detect LE guide vous aide t-il à détecter les épisodes à temps the bloom events on time? No 50% Yes 50% No 40% Yes 60% Presented at: 27 th Eastern Canadian Symposium on Water Quality Research, Canadian Association on Water Quality (CAWQ), Université de Sherbrooke, Sherbrooke, Canada, 26 October 2012

27 Cells/mL EB (Cellules/mL) Cell numbers 80,000 in clarified water , , , Breakthrough of cyanobacteria inside the DWTP#1 100,000 60,000 40,000 20,000 0 Anabaena sp. Anabaena Aphanizomenon sp. Aphanizomenon Microcystis sp. Microcystis Pseudanabaena sp. Pseudanabaena Total Total

28 Cells/mL EB (Cellules/mL) Probes disadvantage: Breakthrough of cyanobacteria inside the DWTP#1 Number of accumulated 80,000 cells in the sludge bed of clarifiers 10,000, ,000 60,000 40,000 Anabaena sp. Anabaena Aphanizomenon sp. Aphanizomenon Microcystis sp. Microcystis Pseudanabaena sp. Pseudanabaena Total 1,000, ,000 10,000 20, , CONCERN: Potential toxin production/release of these cells