ACWA MBR
presents
Submerged Membrane
Bioreactors using the Kubota
Membrane
Rory Morgan, General Manager
MBR Workshop, SAWEA, Nov 29th
C
C C
Presentation Consolidated Contractors
Company
Overview
ACWa Services Ltd (UK)
• Company Information
• The advantages of MBR ACWa MBR
• Detailed information on Aquator Bahrain (Bahrain)
Aquator Emirates (UAE)
reference plants
• Overall design of MBR plants
• The development of the Kubota membrane
• How the Kubota membrane works
• Process control of the Kubota system
• Middle East applications using Kubota membrane
• Conclusion
ACWA MBR (Aquator)
• Originally MBR Technology Ltd
• MBR Technology has Designed and Constructed some
60 SMBR plants, beginning in 1995
• Previously part of Wessex Water
– Responsible for the large scale development of the
Kubota SMBR system
• Established in Bahrain November 2002
• Purchased by ACWa Services Ltd in Feb 2005
• Exclusive licensee for Kubota Membranes in The
Middle East
The Kubota Story
• Pilot plant and testing from 1989, following
Japanese government grant to produce high
quality, low footprint treatment solution
• The membrane was developed
purposefully for wastewater treatment
and not adapted from water treatment
• First commercial plant commissioned 1991
Kubota Corporation
• One of Japan’s leading Environmental
companies
– Tractors & Construction machinery
– Pipes and valves
– Pumps & air conditioning equipment
– Established 1890
– 30,000 employees
– ~ US$10Bn turnover
The Kubota
Flatsheet
• Membranes held firmly
in place and cannot
touch or abrade each
other
• The flat sheet is more
easily kept clean by
coarse bubble aeration
• The flat sheet is
robust and last a very
long time
Features of the Kubota Flatsheet
• Optimum pore size (0.4µm)
• The pore size produces > 6 log removal of
bacteria and > 4 log removal of virus, and is
Title 22 approved, as biofilm layer yields
0.01um performance
• The pore size produces less resistance and thus
the lowest pressure loss through the
membranes
• The lower pressure loss means less force
against the membranes and thus less fouling
• Allows for Gravity Removal of permeate
Features of the Kubota Flatsheet
• Self-sealing
• Fine lattice prevents progress of biomass
through the membrane
• Loss of integrity = Impact on Effluent Quality
• Durable construction
• ABS & high quality polymer that lasts > 10
years
• Ultrasonic weld of membrane to ABS lattice
• Simple lattice structure for low pressure loss
and easy gravity removal of permeate
The Kubota Flatsheet SMBR :
Principle of Operation
In Out
Screened
crude sewage
Treated &
disinfected
effluent
Waste
Sludge
Air in
The Kubota
Membrane
Unit Design
• Stainless steel
and high quality
plastics
• Simple centipede
diffuser
• Designed for
easy
maintenance
Operational advantages of
Kubota flatsheet panel
• Panel is fixed, aeration is maintained at >
0.5m/s velocity
– Scouring is more effective and drag force is
consistent
• Pore size is optimised, so TMP is
minimised
– Drag force is always greater than force
of attachment, as both are controlled
– Cake formation is eliminated
Operational advantages of the
Kubota flatsheet membrane
• No backpulsing is
required
Solids • No daily chemical
Air
Virus
cleaning required
Treated effluent
Bacteria
Membrane
Operational advantages of the
Kubota flatsheet membrane
• Chemical cleaning, when required, is very
simple
– Only required twice per year
– Does not require lowering of tank level
– Does not require removal of biomass from
tank
– Does not require removal of membranes
from tank
– To clean a tank which is rated at 10,000m3/d
would take < 1 day.
Operational advantages of
Kubota flatsheet panels
• Not significantly affected by hair and fibre
• 3mm screen only required
• Not significantly affected by grit
• Many plants operational without grit removal
• Not significantly affected by grease
• Plants operational with up to 300mg/L FOG
• Very long membrane life >10 years
Operational advantages of
Kubota flatsheet panels
• Gravity operation
– No suction pumps = less mechanical equipment and
less problems
– Lower power consumption
• Higher MLSS operation
– More effective scouring allows operation up to
18,000mg/L at competitive fluxes, up to 50,000mg/L
at low fluxes
• Smaller footprint than other MBR plants for same
sludge age
Operational advantages of
Kubota flatsheet panels
• Peaking ability
– Can handle short term peaks up to
1.7m3/m2.d
– As per MWH Title 22 Approval
– General principle to adopt a 2* peaking factor
• Elimination or reduction in balancing volume
Disadvantages of the Kubota
MBR System
• Is designed for wastewater and so requires
incoming biological load
– Not able to be used as tertiary filtration
– Small footprint advantage can be lost on retrofits
– MITIGATION
• Expert focus and specialise on industrial and domestic
wastewater treatment
• Team up with quality process contractors (ACWA) to provide
overall more economic solution
• No backpulsing / online chemical cleaning
– A disadvantage for high fouling waste streams such
as leacheate, chemical wastes
– MITIGATION
• Conservative flux design & overall more economic solution
Process Control of the Kubota
MBR system
• The system is always operated in subcritical
conditions
• A fixed level is adopted, which always provide in
excess of the TMP requirements
Liquid level Liquid level Effective
differential
Differential Pressure Pressure
Membrane
module Unrestricted Restricted
permeate
permeate
MBR Tank manifold
manifold
Process Control of the Kubota
MBR system
1.6
1.4
1.2
1.0
Flux (m3/m2/d)
0.8
0.6
0.4
0.2
0.0
0 10 20 30 40 50 60 70 80 90 100
pD (cm H2O)
Clean Water @ 22 oC Clean Water @ 12oC AS @22oC AS @ 12oC
Process Control of the Kubota
MBR System
1.4 Liquid Level (applied pressure)
1.2
1.0
Pressure (m)
0.8 Perm Differential Pressure
eate
0.6 Pres
sure
0.4
0.2
1 2 3 4 5 6
Month
Change in differential pressure
over time at a constant permeate
flow.
Process Control of the Kubota
MBR System
Height per tank
1 2000 14.5
2 1975 11.9
3 1950 10.6
4 1925 9.3
5 1900 7.9
6 1875 6.6
7 1850 4.0
8 1825 2.6
9 1800 1.3
10 1775 0.0
Process Control of the Kubota
MBR System – Fouling Control
New membrane surface
Process Control of the Kubota
MBR System – Fouling Control
Foulants
Potential foulants:
1. Biomass
2. Organic slimes
3. Inorganic precipitants
4. Fats, oils and greases
Process Control of the Kubota
MBR System – Fouling Control
1. Permeate production
Aeration without aeration will
result in the membranes
fouling.
2. Permeate production with
low aeration with
gradually result in
membrane fouling.
3. An uneven distribution of
air along the membrane
module will result in
membrane fouling.
Process Control of the Kubota
MBR System – Fouling Control
Temperature
1.6
1.4
1. As the liquid
1.2
temperature rises
the viscosity
Flux (m3/m2/d)
1.0
decreases
0.8
2. For every 1oC
0.6
increase in
0.4
temperature there
0.2
is a 2% increase in
0.0
0 10 20 30 40 50 60 70 80 90 100 permeate flowrate
pD (cm H2O)
Clean Water @ 22 oC
Clean Water @ 12oCAS @22oC AS @ 12oC
Process Control of the Kubota
MBR System – Fouling Control
MLSS concentration
1. The ideal MLSS range is 10,000 to 15,000 mg/l
2. At exceptional low MLSS the membrane is separating raw sludge
liquors, which will foul the membranes.
3. At MLSS<7,000 mg/l the cross flow velocity is reduced
4. At MLSS>20,000 mg/l the liquid viscosity is increased significantly
and the cross flow velocity reduced
Process Control of the Kubota
MBR System
• TO PREVENT CAKE FORMATION
• Membrane Relaxation
• Operate at 55mins on / 5mins off
• High Rate Air Scour
• Increase airflow rate for 30mins per day
• TO REMOVAL MICROBIAL FOULING
• Chemical clean of membanes
• TO REPLACE DAMAGES AND SELF-SEALED MEMBRANES
• Pro-active inspections after 4 years and then every 3
years thereafter
Middle East Installations
• ACWA MBR is the leading MBR Designer/Supplier
in the Middle East, with the following milestones
– Commenced with Tubli Bay trial (Bahrain) in 2002
– First full size commercial plant, British American
Tobacco, Turkey, Operational Nov 2002
• 15 installations operational or under
construction, including what will be the largest
SMBR plant in the world, Al Ansab, at
78,000m3/d
Installation Locations - 1 Location: Jordan
Client: Dyncorp
Application :
Location: Torbali, Labour Camp
Turkey Waste
Client: BAT Capacity: 900m3/d
Application : Operational since
Industrial Waste Nov 2004
Capacity: 680m3/d
Location: Al Kharj,
Operational since Saudi Arabia
Oct 2002
Client: Almarai
Location: Izmir, Application :
Turkey Industrial Waste
Client: JTI (Dairy)
Application : Capacity: 4000m3/d
Industrial Waste Operational since
Capacity: 360m3/d June 2005
Operational since Client: Almarai
Jan 2005 Application :
Domestic Waste
Capacity: 600m3/d
Operational since
May 2005
Installation Locations - 2 Location: Palm
Jumeirah, Dubai
Client: Nahkeel / Metito
Location: Tubli Bay, Application : Domestic
Bahrain Waste
Client: Bahrain Capacity: 21,700m3/d
Sewerage
Directorate Operational July 2006
Application : Pilot
Location: Greens,
Plant
Dubai
Capacity: 5m3/d
Client: EMAAR / Metito
Operational 2002-
Application : Domestic
2003
Waste
Location: Messaeid, Capacity: 12,000m3/d
Qatar Operational March 2005
Client:
Location: OGD3/Ruwais, Location: Sharjah, UAE Location: Al Ansab,
Technip/QVC
Abu Dhabi, UAE (4 plants) Muscat, Oman
Client: Sharjah
Application :
Client: CCC Municipality Client: OWSC
Industrial Waste
(Vinyl) Application : Domestic Application : Application : Domestic
Waste Containerised Unit Waste
Capacity: 300m3/d
Capacity: 500m3/d * 4 Capacity: 150m3/d Capacity: 78,000m3/d
Operational since
Nov 2003 Operational Dec 2005 Operational Apr 2005 Operational Nov 2006
Industrial Case Study 1:
BAT Industrial Plant
• Combined Cigarette/Domestic Waste
• 680m3/d Daily Flow
• COD ~ 2000 mg/L
• TSS ~ 550 mg/L
• Client : British American Tobacco
• Location : Izmir, Turkey
• Status: Operational since October 2002
BAT Industrial Plant, Turkey
Industrial Case Study 2:
Qatar Vinyl Industrial ETP
• Existing plant – poor settling sludge
• MBR Retrofit to retain biomass and increase
effluent quality
• Design Flow : 320m3/day
• Client : Technip (Rome)
• COD ~ 2,000mg/L
• Cl- ~ 10,000mg/L
• Location: QVC, Messaid Industrial City, Qatar
• Status: Operational since November 2003
Qatar Vinyl Industrial ETP
Industrial Case Study 3:
Almarai Industrial Plant, KSA
• Waste from dairy operations, Al Kharj
• Full flow 4000m3/d
• 12 no. EK400 membrane units (up to 16)
• COD ~ 2000mg/L
• Retrofit of existing conventional plant
• Client : Saudi Berkefeld – Wetico
• End User : Almarai Corporation
• Status: Operational since June 2005
Almarai Industrial ETP - Diagram
Domestic Case Study 1:
Almarai Domestic Plant, KSA
• Sewage waste from workers, Al Kharj
• Full flow 750m3/d
• 4/6 no. ES200 membrane units
• Client : Saudi-Berkefeld WETICO
• End-User: Almarai Company Ltd
• Status: Operational since April 2005
Almarai STP : Photo
Domestic Case Study 2:
Jordan Labour Camp, Blackwater
• Sewage waste from trainees/workers
• Design flow 360m3/d, upgradable to
900m3/d
• 4/9 no. ES200 membrane units
• Client : Morganti / CCC
• Circular Steel tanks due to rapid
construction requirement
• Status: Commissioned January 2005
Jordan
Blackwater
Treatment :
Photos
Domestic Case Study 3:
Palm Jumeirah Undeground STP
• Nahkeel requirements
– Aesthetic, preferrably ‘unseen’ plant
• Minimised footprint
– No odour
– No noise
– Minimised sludge production
– Low operator requirements
– Very high effluent quality for recycling onto parks and
gardens
• -> Underground MBR Installation
Palm Location
MBR Plant
Domestic Case Study 4:
Al Ansab Water Recycling, Oman
• Will be the worlds largest submerged
membrane plant, to treat a daily flow of
up to 78,000m3/day
• Contract award December 2003
• Collaborative design between Metcalf &
Eddy and Aquator
• Part of the ‘Muscat Water Plan’
Al Ansab : General Arrangement
Membrane Recycle Aeration Anoxic
Tanks Channel Tanks Tanks
Distribution
• Total footprint of treatment tanks is 150m * 50m Chambers
Domestic Case Study 5:
Greens MBR Expansion
• Upgrade of existing extended aeration plant from
3,000m3 -> 12,000m3/d
• Surface aerators replaced with fine bubble
aeration to allow increased MLSS
– -> Maximise existing asset
• Client : Metito
• End User : EMAAR Properties
• ACWA MBR Scope: Design, supply membrane
units, supervision installation and commission
• Status: To be operational March 2006
Greens MBR : Schematic
Recycle
Existing clarifier to be
converted to Anoxic Tank
New 3mm
New MBR
screen
Tank
Existing aeration tank to be
fitted with fine bubble
diffusers
New MBR
Tank
Existing aeration tank to be
fitted with fine bubble
diffusers New MBR
Tank
Domestic Case Study 6:
Ruwais/ODG3 Containers
• 1,000m3/d flow from labour camp
• Short term requirement
– Mobile plant required
• Irrigation Reuse
• Very short construction time available
• Client : CCIC
• ACWA MBR Scope: Complete turnkey contract,
including commissioning and operations
assistance
• Status: To be operational December 2005
Conclusions
• The Kubota membrane is a
remarkable invention that has stood
the test of time
• It is the most robust and simple MBR
solution
