Sandia is a multi-program laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000.

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Introduction
• Water treatment processes
• Materials science for water infrastructure
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Membrane technology- polymeric
• Micro and ultrafiltration (MF and UF)
• Nanofiltration and reverse osmosis (NF and RO)
• Recent RO membrane advances
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• Glass reinforced plastics - corrosion
• Pump coatings - friction reduction
• Pipe lining – trenchless technology
• Composite pumps – corrosion resistant
• Steel alloys (Duplex SS)- corrosion resistant
• Polymers, resins, additives- treatment
• Polymeric membranes- porous: water purification, nonporous: desalinationpressure driven
Source : U.S. Filter
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http://www.gewater.com/products
/equipment/mf_uf_mbr/zeeweed_5
00.jsp
http://www.ionics.com/tech nologies/ro/index.htm#
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Dissolved salts
Nonporous
Suspended solids/ DOM
Porous
Virus Bacteria
Porous: Filtration by size - molecular weight cutoff (MWCO).
Nonporous: Solution diffusion separation – hydrated ions.
Removal: Salinity can be reduced only by RO/NF membrane treatment.
The Future of Desalination in Texas: Texas Water
Development Board
Alyson Sagle and
2,(2004) 137-154
Benny D. Freeman, 6

Coagulant
Flocculation
Coagulation
Sedimentation and or filtration
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Removal of particles and natural organic matter (NOM), color, disinfection byproducts (DBP), iron, manganese, arsenic, taste, odor.
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Granular activated carbon can be used as a filter and adsorber , but regeneration may be different than sand media.
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Coagulant
Microfiltration or
Ultrafiltration concentrate
Coagulation
Flocculation
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Membrane filtration normally uses hollow fiber bundles that can be submerged or pressurized.
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These membranes can be air scoured , backflushed and cleaned and are not usually sensitive to chlorine.
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Pressurized in housing
Source : Pall
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Asymmetric membranes are formed by phase inversion and produces anisotropic material.
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Membrane Polymers
• Polysulfone (PSF),
• Polyethersulfone,
• Poly(vinylidene fluoride),
• Polyacrylonitrile,
• Polypropylene
.
Submerged in cassette
Source: Zeeweed
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Mean pore size ~ size rating of filter (.01 -10 micron)
Lumen
Source:
Koch Membranes
Skin
Porous membranes can be backflushed and cleaned.
Permeate
Feed
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Dead-end membrane operation feed permeate feed
Cross-flow membrane operation
∆P
∆P
Crossflow operation scours the surface and reduces stagnation near membrane surface.
permeate
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‣ thin, dense polymer coating on porous support (composites)
Surface morphology
Journal of Membrane
Science , 158 (1999) 143-153.
Seung-Yeop Kwak, Dae Woo
Ihm
Thin (100 - 200 nm) polyamide membrane
Porous support (polysulfone UF membrane)
Woven mechanical support
*
Discussion will not focus on cellulose acetate asymmetric membranes
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2007 EDS Conference, Halkidiki, Greece
Craig Bartels*, Mashiko Hirose, Hiroki Fujioka
*Hydranautics
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saline feed pretreatment posttreatment high pressure pump concentrate disposal fresh water
•concentration dependent,
• membranes susceptible to fouling,
• pre-treatment required,
• polyamide membranes degraded by Cl
2
.
Thin film composite membrane
RO Plant dense polyamide membrane porous polymer mechanical support
O
NH polyamide
H
2
N
O
NH O
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



Salt rejection,
Water permeability,
Fouling (multifaceted),
Chlorine tolerance.
Normalized water permeability m 3 /(m 2 bar day)
Journal of Membrane Science, 370(2011) 1-22.
Kah Peng Lee, Tom C. Arnot, Davide Mattia 15

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Modification of PSF substrate
•Increase hydrophilicity
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Control of interfacial polymerization
•Crosslinking
•Membrane thickness
•Increase hydrophilicity
•Increased chlorine tolerance
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Surface post treatment
•Modify surface charge
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Membrane morphology
•Surface roughness
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New thin film nanocomposite studies
•Polymer with zeolite, Ag, TiO
2
Journal of Membrane
Science , 370 (2011) 1-22.
Kah Peng Lee, Tom C.
Arnot, Davide Mattia
J. Mater. Chem., 20 (2010)
4551–4566. Dan Li and
Huanting Wang
16

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Energy consumption and membrane costs have been reduced by new membrane formulations.
Journal of Membrane Science, 370 (2011) 1-22.
Kah Peng Lee, Tom C. Arnot, Davide Mattia 17

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Surface modification leads to decrease in contact angle;
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Less fouling potential, somewhat reduced water permeability
Coating solution (mg/L)
Journal of Membrane Science 371 (2001)293-306.
Sanchuan Yu, Zhenhua Lu, Zhihai Chen, Xuesong Liu,
Meihong Liu, Congje Gao
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Smoother membrane surface leads to less fouling
Journal of Membrane Science188 (2001)115-128.
Eric M. Vrijenhoek, Seungkwan Hong, Menachem Elimelech
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Thin film composite membrane dense polyamide membrane porous polymer mechanical support
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Membrane degradation proceeds by chlorination of the amide followed by ring chlorination
Journal of Membrane Science, 300 (2007) 165-171. Guo-
Dong Kang , Cong-Jie Gao, Wei-Dong Chen, Xing-Ming Jie,
Yi-Ming Cao , Quan Yuan
20

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A new polymer formulation holds promise as a chlorine tolerant RO membrane.
Angew. Chem. 120 (2008), 6108 –6113.
Ho Bum Park, Benny D. Freeman, Zhong-Bio Zhang,
Mehmet Sankir, James E. McGrath
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Polymer science and composite fabrication have lead to increased use of membranes and advanced materials in water treatment.
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Microfiltration and Ultrafiltration membranes have provided compact, efficient means of removing suspended solids and wastewater contaminants.
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Nanofiltration and RO membranes provide lower energy alternatives for water desalination.
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