Technologiezentrum Wasser Karlsruhe
The use of ultrafiltration in the public drinking water supply in Germany Dr.-Ing. Pia Lipp, TZW (D) Department of technology, Head of membrane group
Techneau-Workshop „…“ Aachen 14.12.06 Workshop 14.12.06 Aachen
Technologiezentrum Wasser Karlsruhe
The use of UF in the public drinking water supply in Germany - Overview
DVGW – TZW - what is it?
Drinking Water Supply in Germany
Membrane filtration plants in Germany
Recommendations for design, operation, …
Case studies
New plant concepts
Conclusions Workshop 14.12.06 Aachen
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Technologiezentrum Wasser Karlsruhe
DVGW – TZW
Association of German Gas and Waterworks since 1859, independent, non-profit, technical-scientific
Members (gas and water utilities, public authorities, companies, individuals
Fields of work: Regulation, Standardisation, Testing, Certificates, Research and Development, Know-howtransfer, dissemination
TZW = part of DVGW, center for applied research (technology, analytical chemistry, microbiology, environmental biotechnology and site management, groundwater modelling, corrosion, material testing) Workshop 14.12.06 Aachen
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Technologiezentrum Wasser Karlsruhe
Size structure of public water supply 50%
46,7%
6,974 water utilities
45% 40%
36,1%
35%
34,5%
30%
25,3%
25% 20% 15%
12,3%
10% 5%
7,7%
13,7%
11,6%
7,7% 1,9%
1,0%
1,5%
0% < 0.1 Mio. m³/a
0.1 - 0.5 Mio. m³/a
0.5 - 1 Mio.m³/a
number of water supply utilities
1 - 5 Mio. m³/a
5 - 10 Mio. m³/a
> 10 Mio. m³/a
amount of supplied drinking water Workshop 14.12.06 Aachen
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Technologiezentrum Wasser Karlsruhe
Produced Drinking Water by the Public Water Supply in Germany 8000 Total water demand 5,4·109 m³/a
7000
1,000,000 m³
6000 5000 4000 3000 2000
127 L per capita per day
surface water spring water
1000
ground water
0 1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
Workshop 14.12.06 Aachen
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Technologiezentrum Wasser Karlsruhe
Raw water sources in Germany spring water 9% ground water 65%
surface water 26%
rivers 1% bank filtrate 13% lakes and dams 12%
Workshop 14.12.06 Aachen
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Technologiezentrum Wasser Karlsruhe
surface spring ground
Local distribution of Raw Water Sources in Germany
Workshop 14.12.06 Aachen
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Technologiezentrum Wasser Karlsruhe
MF/UFplants in Germany (1.3.06)
Plant capacity 1-10 m³/h 10-50 m³/h 50-250 m³/h 250-1000 m³/h >1000 m³/h
DVGW Kurs 3 – Maschinelle und elektrische Anlagen in Wasserwerken,Workshop Membranfiltration (10.05.06) / Folie 58 14.12.06 Aachen
Technologiezentrum Wasser Karlsruhe
Production capacities of UF-plants 7
1
14
2628 6000
35
1-10 m³/h 34
1-10 m³/h
4761
10-50
10-50
50-250
50-250
250-1000 >1000
number of UF-plants in Germany (Σ 91)
846,9 106,7
250-1000 >1000
plant capacity, m³/h (Σ 14.343 m³/h )
Workshop 14.12.06 Aachen
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Technologiezentrum Wasser Karlsruhe
Origin of raw water for UF-plants 834
4 14
1207,6
17
1387,5 3169,5
7
49
n.n. Quelle Talsperre Brunnen Uferfiltrat
number of UF-plants in Germany (Σ 91)
n.n. Quelle Talsperre Brunnen Uferfiltrat
7744
plant capacity, m³/h (Σ 14.343 m³/h )
Workshop 14.12.06 Aachen 10
Technologiezentrum Wasser Karlsruhe
Membrane types installed in UF-plants 371
4 2
2389
16 28
84 2277,8 949,3
19
22
n.n.
Aquasource
Inge X-Flow
number of UF-plants in Germany (Σ 91)
8271,5
n.n.
Aquasource
PALL
Inge
PALL
Zenon
X-Flow
Zenon
plant capacity, m³/h (Σ 14.343 m³/h )
Workshop 14.12.06 Aachen 11
Technologiezentrum Wasser Karlsruhe
Development of plant installations 100.000 MF/UF-plants total MF/UF-plants plant capacity (MF/UF), m³/h
10.000
1.000
100
10
1 1998
1999
2000
2002
2003
2004
2006
Workshop 14.12.06 Aachen 12
Technologiezentrum Wasser Karlsruhe
Pall 150 m³/h
240 m³/h
Zenon
Inge
600 m³/h
6000 m³/h
X-Flow
Workshop 14.12.06 Aachen 13
Technologiezentrum Wasser Karlsruhe
Integration of membrane filtration in the treatment process
MF/UF (5 %)
MF/UF + disinfection (14 %)
MF/UF + post treatment + disinfection (5 %)
pretreatment + MF/UF + disinfection (14 %)
pretreatment + MF/UF + post treatment + disinfection (14 %)
n.n. (48 %) Results of a survey among 91 MF/UF-plants Workshop 14.12.06 Aachen 14
Technologiezentrum Wasser Karlsruhe
Hygienic Safety of MF/UF-plants for drinking water supply (DVGW, 04/2006)
Treatment of microb. contamin. waters with disinfection z z
Filtrate quality < 0,2 FNU With MF/UF requirements are always kept
Treatment of microb. contamin. waters without disinfection z z z z z z
Only membranes with a virus removal of > 99.99% Proof of 99,99 % virus removal by the manufacturer of the membranes Quality management during production of membranes and modules Online-monitoring of membrane integrity is recommended Direct or indirect online-monitoring of particles in the virus size range is not available Not enough long term experience of UF operation available
Recommendation: if particle removal by UF is the only treatment step => a disinfection should be provided Workshop 14.12.06 Aachen 15
Technologiezentrum Wasser Karlsruhe
Technical Rule W 213-5
Definitions
Requirements - for membranes - for modules in plants
• Rohwasser = Feed • Filtrat bei Mikro- /Ultrafiltration (Permeat bei Umkehrosmose/Nanofiltration) • Spezifische Flächenbelastung (Filtratfluss, Flux) = Filtratmenge / Membranfläche (L/m²/h) • Transmembrandruck = mittlerer Feeddruck - Filtratdruck • Permeabilität (L/m²/h/bar) bei 20°C = Flux / TMP • Fouling (Verblockung) = Verminderung der Durchlässigkeit • Ausbeute = Filtratmenge bezogen auf Rohwassermenge • Dead-End- bzw. Cross-Flow-Betrieb • Trenngrenze - Porenweite oder Rückhalt (MWCO = molecular weight cut off)
Recommendations for design and operation, monitoring … • • • • •
Übersichtlicher Aufbau Hydraulisch gleichmäßige Beschickung Spülbarkeit Be- und Entlüftung, Entleerung Probenentnahmemöglichkeiten
• Einheitliche Porenweite • Materialbeständigkeit (mech. und chem.) • Beständigkeit gegen Biofouling • KTW-Empfehlung • DVGW W 270 • DIN EN 12873-4 (Entwurf) Workshop 14.12.06 Aachen 16
Technologiezentrum Wasser Karlsruhe
monitoring / integrity
control of operation data regularly
turbidity measurement continuously
analysis of bacteriology every 1 or 2 weeks
particle counting (1-100 µm) UF-filtrate every now and then
integrity testing with pressure decay once a year
Anzahl Partikel (1-100 µm) pro mL
10000
Spülung der Membranen
1000
100
10
1 Zulauf UF
Gesamtablauf UF
Einzelablauf UF
0 29.11.04 10:00
10:10
10:20
10:30
10:40
10:50
11:00
11:10
11:20
11:30
11:40
Workshop 14.12.06 Aachen 17
Technologiezentrum Wasser Karlsruhe
Steps to establish UF
Monitoring of raw water quality (turbidity, microbiology, phys.-chem. parameters, dissolved organic compounds)
Determination of site conditions
Elaboration of treatment concept
Pilot plant investigations z z z z z
worst case raw water quality and representative time What is the most suitable membrane system? Where should UF-plant be integrated? Find out operation conditions to be used as basic data for the large scale application Find out optimal conditions for backwash and chemical cleaning
Workshop 14.12.06 Aachen 18
Technologiezentrum Wasser Karlsruhe
Evaluation of optimal backwash conditions
Backwash with acid/base
Backwash with NaOCl
Workshop 14.12.06 Aachen 19
Technologiezentrum Wasser Karlsruhe
Long term behaviour of UF-membranes
300
dosing of flocculant
chemical cleaning mean TMP at 20°C backwash water demand, %
filtrate+acid/base
200
100 15 10 5
0 1999
0
2000
2001
2002
2003
2004
2005
2006
backwash water demand, %
TMP (20°C) with 60 m³/h, mbar
backwash with filtrate + H2O2 (sometimes NaOCl)
filtrate + NaOCl
400
Workshop 14.12.06 Aachen 20
Technologiezentrum Wasser Karlsruhe
Influence of backwash chemicals Skid 4
Skid 1
Skid 3
Skid 2
25 backwashes with H2O2
24
backwashes with H2O2
backwashes with H2O2
23 22 21 20 19 18 17 16 15
backwash with Cl2
mean flux (45 L/m²/h)
02-04-10
02-04-24
02-05-08
02-05-22
02-06-05 Workshop 14.12.06 Aachen 21
Technologiezentrum Wasser Karlsruhe
Long term behaviour – influence of chemically enhanced backwash acid/base-backwash every 12 h
every 8 h
every 7 h
Permeability (20°C), L/m²/h/bar
500
400
300
200
100
permeability (20°C) chemical cleaning dosing of flocculant backwash with NaOCl
filtrate backwash every 1,5 h
0 01.05.04
31.07.04
31.10.04
30.01.05
02.05.05
01.08.05
01.11.05
31.01.06 30.04.06
Workshop 14.12.06 Aachen 22
Technologiezentrum Wasser Karlsruhe
Characterisation of dissolved organic matter 12 Hermeskeil 19.10.05
C
10 Rel. Signalheight OCD
E values, µg/L raw water feed of UF-plant filtrate of UF-plant
D
8
TOC 1537 1308 1217
A 177 222 172
A B C D E F G
6
4
B 87 12 10
C 617 437 435
D 330 315 309
E 153 166 148
F 173 156 142
G 0,58 0,04 0,02
HOC+POC polysaccharides humic substances building blocks neutral substances low molecular substances inorg. Colloids
raw water
2
B
F
feed of UF-plant filtrate of UF-plant
0 20
30
40
50
60
70
80
90
elution time, min Workshop 14.12.06 Aachen 23
Technologiezentrum Wasser Karlsruhe
New UF-plant concepts
Target group: small-scale systems (0,1 to 10 m³/h)
Lower level of equipment compared to large-scale plants
Lower investment costs
Chemical cleaning / integrity test => within service package
COP: Cleaning out of place
DVGW/UVM – research project “COP-Membranes”
Workshop 14.12.06 Aachen 24
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Examples for COP-UF-plants 2,2 m²
6,2 m²
only forward-flush
9 m²
forward- and backflush
50 m² membrane area
Backwash with filtrate and air / forward- and backflush Workshop 14.12.06 Aachen 25
Technologiezentrum Wasser Karlsruhe
Specific investment costs 100.000 spec. investment costs, € / (m³/h)
COP
CIP
NF/UO
investment costs for equipment only
10.000
1.000 0,1
1
10 100 plant capacity, m³/h
1000
10000
Workshop 14.12.06 Aachen 26
Technologiezentrum Wasser Karlsruhe
Conclusions MF/UF
Development from R&D to the state of the art
Increasing operation experiences
There is still need for z
optimization of backwash and cleaning processes – Influence of raw water quality – Difference of membrane systems
z
Research and development of fouling resistant membranes
z
Other applications …
Workshop 14.12.06 Aachen 27
