josef lahnsteiner, va tech wabag - gpw. · pdf fileplant raw water capacity start-up [m 3/day]...
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1sustainable solutions. for a better life.
sustainable solutions. for a better life.
Freshwater Membrane Filtration including Retentate Disposal/Recycling
Josef Lahnsteiner, VA TECH WABAG
HydroSilesia
Konferencja Hydrointegracje 2011
Sosnowiec, October 13th, 2011
2sustainable solutions. for a better life.
O u t l i n e
Introduction
Case study 1 - Lake water treatment, Männedorf and Meilen, Switzerland
Case study 2 - Treated sewage transformed into potable water, Windhoek, Namibia
Case studies 3 - Ground water treatment, Delhi, India
Conclusions
3sustainable solutions. for a better life.
Major Potable Water Membrane References
Plant Raw Water Capacity Start-up[m3/day]
Membrane Supplier
Chennai/Nemmeli, India Sea water 100,000 2012 X-Flow
Cudrefin, Switzerland Lake water, Backw. w. 3,000 2012 Inge & Zenon
Horgen, Switzerland Lake water 25,000 2012 Zenon
Duqm, Oman Sea water 16,000 2010 Pall
Delhi/CWGV, India Well water 4,545 2010 X-Flow
Grabs, Switzerland Spring water 2,500 2010 Zenon
Männedorf, Switzerland Lake water, Backw. w. 16,000 2005 Inge & Zenon
Meilen, Switzerland Backwash water 360 2005 Zenon
Windhoek, Namibia Secondary effluent 21,000 2002 X-Flow
Tavannes, Switzerland Spring water 2,400 2002 Zenon
4sustainable solutions. for a better life.
Main advantages of Ultra Filtration
Complete removal of suspended solids
Partial removal of dissolved matter (TOC, DOC, COD, BOD)through binding to suspended matter
Removal of micro-organisms
> Log 6 removal of protozoa
> Log 6 removal of bacteria
> Log 4 removal of viruses
Superb quality as RO feed water (low SDI15)
Certified for use in potable water treatment
5sustainable solutions. for a better life.
Männedorf WTP, Switzerland
Lake water treatment
Multi Barrier System
Operational since 2005
6sustainable solutions. for a better life.
Männedorf WTP, SwitzerlandRaw water source
Lake water
Capacity
8,000 m³/d of drinking
water
Peak flow 1,000 m³/h
Pre-treatment
Ozonisation
BAC
Membrane filtration
Tubular membranes (Inge)
Start-up
2005
7sustainable solutions. for a better life.
Männedorf WTP
Pressurised Membranes Dizzer 5000
No disinfection of clean water or
protection of the network needed
anymore
Chemical cleaning every 24 – 30 hours
Recovery cleaning once per year
Backwash water treatment
8sustainable solutions. for a better life.
Männedorf WTP - Backwash water treatment
Submerged Membranes - Zenon
ZW500D
Start-up 2006
Capacity 100 m3/h
No pre-treatment
Chemical cleaning every 36 hours of
service
Recovery cleaning once per year
Permeate flows back to the lake
9sustainable solutions. for a better life.
Männedorf – Submerged Membranes for Backwash Water Treatment
The permeability on both treatment lines remains stable;
the diagram shows the course of the permeability over a 8
month period, the values remain at high levels between
140 und 170 l/m2*h*bar.
The plant is in operation since January 2006.
Filtration for 15 min
Back wash for 30 sec
Maintenance 48 h of operation
Recovery once per year
10sustainable solutions. for a better life.
Process Technology
Client: Municipality of Meilen Contract award: June 2004
Capacity: 24,000 m3/d Start-up: May 2005
Plant Key Data
Project
The existing plant from 1972 had to become rehabilitated. During the whole construction time the municipalities were supplied with
sufficient water in good quality. The upgrading of the treatment plant is not only the result of new equipment but also by an extension of
the process engineering from double to multi-layer filtration and from one ozonation stage to a pre- and intermediate ozonation.
Characteristics
Water from lake Zurich is treated and supplied to the municipalities of Meilen
(52%), Herrliberg (35%) and Egg (13%).
The lake water contains small amounts of various micro-pollutants which
means a challenge to the conventional treatment chain.
The produced drinking water meets at minimum the Swiss drinking water
standards.
• Dosing of flocculant
• In-line pre-ozonation by partial flow system
• Filtration through multi-layer filters (filter media: expanded lay, anthracite and quartz sand)
• In-line Intermediate-ozonation by partial flow system
• Filtration and adsorption through Activated Carbon Filters
• Supply net protection
• Drinking water distribution to the municipalities
• Fully automatic backwash sequences
• Used backwash water ultrafiltration by submerged membranes
• Automatic control system
• On-line quality supervision
11sustainable solutions. for a better life.
Process Scheme
1 Lake Zurich, raw water source
2 Raw water pump station
3 Dosing of flocculant
4 pre-ozonation
5 Multi-layer filtration
6 Intermediate pump station
7 Intermediate ozonation
8 Activated carbon filters
9 Supply net protection
10 Clean water tank
11 Multi-stage pump station for water supply to the municipalities
12 Backwash water pumps
13 Used backwash water tank
14 Ultrafiltration with submerged membranes (used backwash water treatment)
15 Recycle of permeate to the multi-layer filter inlet
Production capacity 1000 m3/h
Numbers of treatment lines 2
Output of main water treatment > 97 %
Wastewater amount to sewage system < 0.4 %
Technical data
WABAG Wassertechnik AG, Winterthur/Switzerland, [email protected], www.wabag.com
12sustainable solutions. for a better life.
Meilen WTP, Switzerland
Backwash Water Recycling
Submerged Membranes ZW500C
Start-up 2006
Capacity 18 m3/h
No pre-treatment
Chemical cleaning every
week of service
Recovery cleaning once per year
Permeate flows back to the raw
water and into the process
13sustainable solutions. for a better life.
Backwash Water Treatment by Submerged Membranes
Maennedorf WTP Meilen WTP
Parameter Unit
Retentate
concentrated
Backwash Water
Permeate
Membrane Filtrate
Retentate
concentrated
Backwash Water
Permeate
Membrane Filtrate
Turbidity NTU n.d. (not detected) <0.02 n.d. (not detected) <0.02
Suspended Solids mg/l 244 n.d. 560 n.d.
DOC mg/l 11.6 1.2 5.9 1.3
UV254nm 1/m 5.32 1.26 4.24 1.35
Volatile Suspended Solids mg/l 80 n.d. 183 n.d.
Volatile Suspended Solids % 32.8 n.d. 32.6 n.d.
Heterotrophic Plate Count (30°C) CFU/ml n.d. <10 n.d. <10
14sustainable solutions. for a better life.
Maennedorf WTP - Water Balance in May 2009
Parameter UnitPotable Water
ProductionBackwash Water
DemandRecycled Backwash
WaterSludge Water
disposed
Absolute Quantity [m3/month ] 147.232 20.598 17.747 2.851
Relative Quantity [%] 100 14.0 12.1* 1.9**
*86,2 % of backwash water is recycled;
**13.8 % of backwash water is discharged into the sewer
15sustainable solutions. for a better life.
Meilen WTP - Water Balance in 2006
Parameter UnitPotable Water
ProductionBackwash Water
DemandRecycled Backwash
WaterSludge Water
disposed
Absolute Quantity [m3/a] 1.591.582 24.996 20.609 4.393
Relative Quantity [%] 100 1.57 1.29* 0.28**
*82,5% of backwash water is recycled;
**17,5% of backwash water is discharged into the sewer
16sustainable solutions. for a better life.
Potable Water from Secondary Domestic EffluentWindhoek, Namibia
17sustainable solutions. for a better life.
Goreangab dam
Gammams WWTP
New Goreangab WRP
City of Windhoek
24,000 m³/d
Simplified Water Reuse Scheme
Von Bach Dam WTP
average approx.40,000 m3/d
approx. 30,000 m3/d
Industrial WW
18sustainable solutions. for a better life.
Concerns to Potable Reuse
Transmission of pathogens including viruses
Trace organics and its potential toxic effects
Aesthetic concerns
Reliability of employed treatment process
Multiple barrier principle
19sustainable solutions. for a better life.
New Goreangab Water Reclamation Plant
20sustainable solutions. for a better life.
NGWRP - Major Quality Parameters
Major Parameters Units Raw water (design values)
Treated water (guarantee values)
Results at performance test
Physical & Chemical
Turbidity NTU 53 0.1 0.08
DOC mg/l 15 5 1.0
THM µg/l 169 20 11
Microbiological
Giardia per 100 ml 214 0 or log 6 removal 0
Cryptosporidium per 100 ml 334 0 or log 6 removal 0
E. Coli per 100 ml 20,347 0 0
21sustainable solutions. for a better life.
Ultrafiltration process step – Goreangab Water Reclamation Plant
22sustainable solutions. for a better life.
NGWRP - Membrane Plant Average Figures
Normal Backwashes with Permeate - Recycling
Racks in Operation 4
Hours of Operation 18
Duration before Back flush (min.) 40
Duration of Back flush (sec) 40
Flow Rate during Back flush (m3/h) 490
Daily Avg. Total Water Consumption for Back flushes (m3) 588
Chemical Enhanced Backwash (CEB) – Discharge into the Sewer
CEB2 after 8-9 water back flushes with NaOCl + NaOH
CEB1 follows after 4 x CEB2 with HCl
Typical Chemical Enhanced Back washes
Total Daily Avg. Consumption of HCl [35%] (L) 20
Total Daily Avg. Consumption of NaOCl [12-14%] (L) 40
Total Daily Avg. Consumption of NaOH [47%] (L) 130
23sustainable solutions. for a better life.
Commonwealth Games Village WTP, Delhi, India
Ground water treatment
Capacity: 4,600 m3/d
Start-up: 2010
Akshardham Temple
24sustainable solutions. for a better life.
Inlet Parameters Outlet Parameters
Flow 4,773 m³/d 4,546 m³/d
(Hydraulic design margin 20%)
pH 7.2 – 8.6 7.5 – 8.5
Turbidity 50 NTU <0.5 NTU
CO2 2 mg/l
Alkalinity 550 mg/l
Total hardness as CaCO3 500 mg/l <200 mg/l
Ca as CaCO3 375 mg/l 100 mg/l
Mg as CaCO3 125 mg/l 80 mg/l
Sulfate as SO4 115 mg/l 250 mg/l
Chloride as Cl 190 mg/l
Nitrate as NO3 20 mg/l 10 mg/l as N
Total Iron as Fe 0.85 mg/l 0.3 mg/l
Nitrite as NO2 0.50 mg/l 1.0 mg/l as N
Fluoride as F 0.90 mg/l 1.5 mg/l
Colour 0.05 Hz Units
Residual Chlorine 0.2 – 0.5 mg/l
Coliforms (E.coli/Total) Nil #/100 ml
25sustainable solutions. for a better life.
Borewell 1Ranney Well 4
Borewell 2
Borewell 3
Borewell 1
Cascade Aerator
Reaction Tank
Reactor Clarifier (HRSCC)
Recarbonization Reactor
Tube Settler
Filter Feed Buffer Tank
Membrane Filtration
(UF)
UV Disinfection
Treated Water
Reservoir
Sludge Collection Sump
CentrifugeChlorine Dosing
Thickener
DWPE Dosing
CO2 Dosing & HCl Dosing
Provision
PAC & Polyelectrolyte
Dosing
Centrate / Supernatant Sump
Centrate
Supernatant
Chlorine Dosing
Waste Backwash Water
Sludge
Sludge for Disposal
Polyelectrolyte Dosing
For Distribution
PAC Dosing
Lime Dosing
Coarse Bubble
AerationBasket Strainer
140 MGD WTP at Sonia Vihar (Act as standby source if ground water quality /
quantity is insufficient)
Borewell 1Ranney Well 4
Borewell 2
Borewell 3
Borewell 1
Cascade Aerator
Reaction Tank
Reactor Clarifier (HRSCC)
Recarbonization Reactor
Tube Settler
Filter Feed Buffer Tank
Membrane Filtration
(UF)
UV Disinfection
Treated Water
Reservoir
Sludge Collection Sump
CentrifugeChlorine Dosing
Thickener
DWPE Dosing
CO2 Dosing & HCl Dosing Provision
PAC & Polyelectrolyte
Dosing
Centrate / Supernatant Sump
Centrate
Supernatant
Chlorine Dosing
Waste Backwash Water
Sludge
Sludge for Disposal
Polyelectrolyte Dosing
For Distribution
PAC Dosing
Lime Dosing
Coarse Bubble
AerationBasket Strainer
140 MGD WTP at Sonia Vihar (Act as standby source if ground water quality /
quantity is insufficient)
26sustainable solutions. for a better life.
AquaFlex™ Ultrafiltration
8” Aquaflex modules:
DIN 0.8 mm / L 1.5 m � 40 m2
PES fibrespore size 25 nm
Corrugated plates:optimal
hydrodynamics
27sustainable solutions. for a better life.
Conclusions
Water processes using membrane filtration are state of the art
However, optimization is carried out - mainly for pre-treatment, membrane properties, membrane cleaning and recovery
High water recovery rates are demanded, especially in water stressed regions; retentate recycling is technically feasible
However for safety reasons, only water which comprises a better quality than the raw water should be recycled; chemical back wash water should be discharged
Whatever the case, membrane filtration - if properly designed -improves the water quality and subsequently increases the safety ofthe consumers
28sustainable solutions. for a better life.
Thank you for your attention!