Flow cytometry in drinking water research: case-study Amsterdam Marius Vital, Marco Dignum, Aleksandra Magic, Petra Ross, Luuk Rietveld and Frederik Hammes
Overview Waternet s philosophy behind safe drinking water Description of treatment steps Results from Techneau case-study Amsterdam 2009 Future research interests marco.dignum@waternet.nl 2
First watercycle company in The Netherlands Waternet takes care of the water cycle in Amsterdam and surroundings, including: Dikes and flood protection Management of surface and ground water Sewage system and waste water treatment Production and distribution of drinking water marco.dignum@waternet.nl 3
marco.dignum@waternet.nl 4
Philosophy behind safe drinking water The 5 rules of Peter Huck (prof @ University of Waterloo): 1. Protect the source 2. Good treatment 3. Good distribution 4. Monitor the quality 5. Ready for direct action + Try out new possibilities in a pilot plant marco.dignum@waternet.nl 5
Drinking water treatment Leiduin en Weesperkarspel (LDN) (WPK) Google Earth marco.dignum@waternet.nl 6
Differences in the two watertypes Tabel 1. Jaargemiddelde waarden van de voor dit onderzoek relevante waterkwaliteitsparameters van het reine water van Leiduin (LDN) en Weesperkarspel (WPK) (gemiddeld over 2007 ± 95% betrouwbaarheidsinterval; aantal vrijheidsgraden tussen haakjes) Parameter LDN WPK ph 8.17 ± 0.02 (51) 7.92 ± 0.03 (51) Chloride (mg.l -1 ) 87.9 ± 1.4 (51) 79.4 ± 1.0 (51) Sulfaat (mg.l -1 ) 48.4 ± 1.0 (25) 9.0 ± 0.7 (12) Bicarbonaat (mg.l -1 ) 166.7 ± 2.1 (51) 176.7 ± 1.2 (62) TOC (mg.l -1 ) 1.19 ± 0.08 (27) 2.89 ± 0.09 (50) AOC (µg ac-c.l -1 ) 6.4 ± 1.1 (11) 18.4 ± 3.5 (14) Aeromonas spp. (cfu.l -1 ) af pomp 19 ± 8 (51) 390 ± 110 (81) Aeromonas spp. (cfu.l -1 ) in de periferie van het distributienet* 730 ± 280 (51) 8220 ± 1270 (237) *Gemiddelde over 10 verst gelegen monsterpunten met verblijftijd groter dan 48 uur 3 ~ 0,5% 10! marco.dignum@waternet.nl 7
pre-treated water rapid filter marco.dignum@waternet.nl 8
pre-treated water rapid filter ozonation marco.dignum@waternet.nl 9
pre-treated water rapid filter ozonation PSF marco.dignum@waternet.nl 10
pre-treated water rapid filter ozonation PSF BAC marco.dignum@waternet.nl 11
pre-treated water rapid filter ozonation PSF BAC slow filter reservoir marco.dignum@waternet.nl 12
pre-treated water rapid filter ozonation PSF BAC slow filter reservoir Network (5x) PS Osdorp marco.dignum@waternet.nl 13
pre-treated water rapid filter ozonation PSF BAC slow filter reservoir Network (5x) PS Weesperkarspel marco.dignum@waternet.nl 14
Parameters measured 1. FCM intact cell counts 2. Cellular ATP 3. HPC / Aeromonas 4. Organic carbon: AOC and DOC marco.dignum@waternet.nl 15
How does flow cytometry work? Microscope lens Laser Capillary Stained bacteria marco.dignum@waternet.nl 16
FCM direct cell count (n/ml) pre-treated water rapid filter ozonation PSF BAC slow filter reservoir Network (5x) 10000000 WPK LDN 1000000 100000 Ozon dose 10000 LDN: 0,35 mg O 3 /mg C 1000 extraction point rapid filter ozonised water softened water carbon filtrate drinking water WPK: 0,33 mg O 3 /mg C distribution 1 distribution 2 distribution 3 distribution 4 distribution 5 marco.dignum@waternet.nl 17
AOC (µg/l) pre-treated water rapid filter ozonation PSF BAC slow filter reservoir Network (5x) 220 200 180 160 140 120 AOC removal 62% WPK LDN 100 80 60 40 20 59% 0 extraction point rapid filter ozonised water softened water carbon filtrate drinking water distribution 1 distribution 2 distribution 3 distribution 4 distribution 5 marco.dignum@waternet.nl 18
FCM (cells/ml) ATP (ng/l) pre-treated water rapid filter ozonation PSF BAC slow filter reservoir Network (5x) 1,0E+07 WPK FCM ATP 1,0E+03 1,0E+06 1,0E+02 1,0E+05 1,0E+01 1,0E+04 1,0E+00 1,0E+03 extraction point rapid filter ozonised water softened water carbon filtrate drinking water distribution 1 distribution 2 distribution 3 distribution 4 distribution 5 1,0E-01 marco.dignum@waternet.nl 19
Plate count (cfu/ml) Aeromonas (cfu/ml) pre-treated water rapid filter ozonation PSF BAC slow filter reservoir Network (5x) 1,0E+05 WPK HPC25 HPC22 Aeromonas 1,0E+02 1,0E+04 1,0E+01 1,0E+03 1,0E+00 1,0E+02 1,0E+01 1,0E-01 1,0E+00 extraction point rapid filter ozonised water softened water carbon filtrate drinking water distribution 1 distribution 2 distribution 3 distribution 4 distribution 5 1,0E-02 marco.dignum@waternet.nl 20
Summary Actual biomass Potential biomass RSF - - Ozone -- ++ PSF + -- BACF + -- SSF - - DWDS 0 0 marco.dignum@waternet.nl 21
Conclusions Flow cytometry and ATP are fast and easy, cultivationindependent methods for overall biomass estimation These methods correlate well and show the same pattern for both treatment plants In some cases, the methods are complementary Only a small fraction of bacteria can be cultivated; plate counts show inconsistent patterns Overall, production of hygienically safe and biologically stable drinking water without chlorine residual is possible A very specific population Aeromonas- shows instability marco.dignum@waternet.nl 22
Operational issues Aeromonas control (BTO) Rapid detection of Enterobacteria (Waterlab Noord) Biofilm prevention in PE pipes Breakthrough of slow sand filtration Influence of temperature on biological stability and emerging pathogens (BTO) marco.dignum@waternet.nl 23
Future research interests Foodchain in an oligotrophic environment: what is biological stability? Understanding and preventing Legionella growth (BTO) Does microbial corrosion play a role in pipe ageing? Relationship between particle sedimentation and bacterial growth Role of protozoa as vector for pathogenic bacteria? marco.dignum@waternet.nl 24