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MABMEM-A Toolbox for HighPerformance UF-Membranes
Martin Weber, BASF SEMABMEM Team
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Outline
• Introduction
• Objectives – Relation to MachWas Program
• Team/Workflow
• Results
• Conclusions
• Acknowledgements
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Socio Economic Megatrends
Source: EV/BS, ZZS forecast, UN, Lux Research
PopulationGrowth
+1.1% p.a.
Urbanization+50% 2008-30
Industrialization+3.2% p.a.
Resource Contamination-5% usable water by 2030
Energy Demand Efficiency
2005 202020156.5bn 7.6bn7.2bn
Water Supply & Demand Balance 2030Km³, based on 154
basins/regions
1) Agricultural production projections from IFPRI 2) Based on
GDP, population projections and agricultural production
projections
from IFPRI; no water productivity gains considered between
2005-20303) Existing supply which can be provided at 90%
reliability, based on historical
hydrology and infrastructure investments through 2010Source:
Charting our Water Future, 2009
900
600
3.500
7004,200
Agriculture
Industry
Municipal &Domestic
SurfaceWater
GroundWater
Existing accessible, sustainable
supply3)
2030 withdrawals2)
6,900
4,500
1,500
Existing withdrawals1)
4,500
3,100
800
-39%2%
CAGR 2010-30
IntroductionMegatrends and Water Industry Challenges
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IntroductionMembrane Separation Technologies
Pressure [bar]
102
101
100
10-1 10-1110102103104105
102 10 1 10-1 10-2 10-3 10-4
[nm]
[µm]
FiltrationMicrofiltration
Ultrafiltration
Nanofiltration
Reverse Osmosis
Pollen Yeast Virus Atoms
Protozoa Bakteria Aqu. Salts
Colloids Org. Compounds
Organic Macromolecules
Porediameter
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IntroductionUltrafiltration in Water Treatment
Ultrafiltration
Ground, Lake & Surface Water
Industrial Treatment
Municipal Treatment
Sea Water Waste Water
Local
PoU PoE PoU = Point of UsePoE = Point of Entry
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IntroductionInfluence of Fouling
• Performance of UF-membranes limited by fouling issues•
Hydrophilic membrane materials show lower fouling tendency•
Additional functionalities of UF-membranes possible?
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IntroductionHollow Fiber Spinning Process
Bore Fluidwater / solvent
Polymer DopePESU, PVP,
NMP, additives
Coagulation Extraction, post treatment
Air Gap
Coagulation Bath
Pore size ~ 30 nm
Multibore® Fiber
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IntroductionModification of the Membrane Surface
Membrane formation process
hydrophilic surface
„matrix“
Precipitation(Vitrification in a few seconds!!)
„matrix“-approach- low Tg of PESU-PEO!!
„additive“-approach- higher Tg- Mobility of additive
- hydrophilicity- mobility- miscibility- ...
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Objectives of MABMEMRelation to MachWas Program
• Improve permeability of UF-membranes• Improve chemical
resistance of UF-
membranes• Create basic knowledge for the design of
appropriate additives
• Integrate additional functionality forion removal
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Approach of MABMEMA Toolbox for Membranes
Toolbox
Base Polymers
PESU
PPSU
-“high flux“- high porosity- PWP > 1500 l/m² h bar- MWCO <
100 kD
-“chemical resistant“- PPSU based- PWP > 500l/m² h bar - MWCO
< 50 kD
- „tight UF- PWP > 400l/m² h bar- MWCO < 10 kD
- UF + selective adsor-ption of heavy metals
- PESU-PEO- PESU-PPO- PESU-PEO-PPO
- PPSU-PEO- PPSU-PEO-PPO-PEO
- PEI-PSU-PEI- PPO/PEO-PSU
- Coating of membranestructure
Additives
+
UF/MF - Membranes
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Team/Workflow
Start: 01.05.2016; duration 3 years
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ResultsAdditive Synthesis
Y = H: PESU multiblock copolymer
X: PEO
X: PPO
X: Poly THF
X: PIB
Hyd
roph
ilici
ty
Flex
ibili
ty
Miscible with PESU: Tg decrease
Not Miscible with PESU: Tg of PESU almost constant
n n-x x HO - (EO)n - X - (EO)n - O-Y
Y = Me, R: PESU triblock copolymer
“blocky“-structure due toreactivity difference
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ResultsAdditive Synthesis – PEO-PESU-PEO
+ + HO - X - O-Alkyl
PESU-Multiblock-Copolymer
X: PEO
• Variation of PESU block length by stoichiometry
• Composition can be tuned by amount andblock length of
hydrophilic unit
• Variation molecular weight possible
• High conversion allows direct use of additive solution
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ResultsViscosity Functions of Solutions
• Cox-Merz Rulevalid
• Solutions con-taining additiveshave lower vis-cosity
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ResultsMembrane Preparation (Flat Sheets)
Influence of post treatment on membrane properties was
investigated Self-made dope solution was used
Tenfold increase of permeability after post treatment Self
prepared dope solution similar to supplied one (BASF) Reduction of
PVP during post treatment clearly detectable in ATR-FT-IR Contact
angle ≈ 70º for all three membranes (sessile drop method)
0
20
40
60
80
100
0
200
400
600
800
1000
without posttreatment
with posttreatment
self prepareddope solution -
with posttreatment
Rej
ectio
n [%
]
Perm
eability [Lm
‐2h‐
1 bar
‐1]
Base Membrane
Permeability Rejection
0
20
40
60
80
100
120
640114016402140264031403640
Transm
ission [%
]
Wavenumber [cm‐1]
ATR‐FT‐IR
With post treatment Without post treatment
PVP
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ResultsMembrane CharacterisationStructure analysis – SEM
Without post treatment after post treatment self-made dope
solution –after post treatment
All samples show regular sponge like bulk structure and defined
separation layer
SEM analysis shows no difference in general membrane structure
after post treatment
CrossSection
Top
Bottom
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ResultsFiber Spinning
-0026-1
200 µm
-0026-3
-0026-4
-0026-5
-0026-6
-0026-9
-0026-8
-0026-7
-0026-2
Mn of PESU-block orreference1. 2,4 kDa2. 4,2 kDa3. 12,9 kDa4.
6,1 kDa5. 2,6 kDa (Add. Pluriol)6. 2,4 kDa (Add. Pluronic)7. 3,5
kDa (St. Lutensol)8. 4,7 kDa (St. Pluriol)9. 14 kDa (St.
Pluronic)
Mn of PESU-block orreference1. 2,4 kDa2. 4,2 kDa3. 12,9 kDa4.
6,1 kDa5. 2,6 kDa (Add. Pluriol)6. 2,4 kDa (Add. Pluronic)7. 3,5
kDa (St. Lutensol)8. 4,7 kDa (St. Pluriol)9. 14 kDa (St.
Pluronic)
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ResultsModule Preparation
• Sealant needs to penetrateinto the membrane structureto avoid
“axial leakage“
• Viscosity of sealant needs tobe low, pot life realtively
high
• Potting system has to beadjusted to membrane material
Modules for short-term fouling tests
(0,036 or 0,051 m2 filtration area)
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ResultsAdsorptive FoulingEvaluation of fouling conditions
50 % dilution and 24 h fouling time will be used for further
experiments
Membrane
Foulant0510152025303540
0 5 10 15 20 25
RFR [%
]
Time [h]
RFR − Influence of me
0
10
20
30
40
50
0 20 40 60 80 100
RFR [%
]
Dilution [%]
RFR − Influence of concentration
Diluted flower soil was used
RFR addicted to concentration
Concentrated flower soil was used
Relative flux reduction (RFR) as indicator for fouling
Significant fouling already after 8–16 h
Without Fouling
After 24 h
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ResultsFouling Tests
“Poseidon" Ultrafiltration plant (UF) from Convergence Industry
B.VFiltration and backwash pressure: 0- 6 bar
Filtration flow rate: 4-200 L/hBackwash flow rate: 2- 100
L/h
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ResultsFouling Trials with Flower Soil1.c)
21
Pure waterfiltration
Foulantfiltration
Pure waterfiltrationand BW (3x)
Chemi-cal cleaning
Pure waterfiltration andBW (3x)
Flower soil causes strong fouling, but no irreversible
fouling
Pure waterfiltration
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Conclusions
• Large number of new additives prepared andcharacterised
• Membrane formation works for most of theadditives,
characterisation of the membranes (flat sheets, fibers) on
going
• Fouling procedures and several possible foulantsinvestigated,
focus on flower soil extract
• First additives for metal adsorption prepared, membrane tests
started
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Acknowledgements
• BMBF for funding
• PTJ for support
• MABMEM-Team (UDE, IWW, HZG, inge, BASF SE)
