Transcript Chemical Security ProgramThe Role of Chemistry and

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.
‣ Introduction
• Water treatment processes
• Materials science for water infrastructure
‣ 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
Source : U.S. Filter
• 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
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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 2,(2004) 137-154
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Alyson Sagle and Benny D. Freeman,
Coagulant
Coagulation
Flocculation
Sedimentation and
or filtration
‣
Removal of particles and natural organic matter (NOM), color,
disinfection byproducts (DBP), iron, manganese, arsenic, taste, odor.
‣
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
‣
Membrane filtration normally uses hollow fiber bundles that can be submerged or
pressurized.
‣
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
‣
Asymmetric membranes
are formed by phase
inversion and produces
anisotropic material.
‣
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
Permeate
Feed
Skin
Porous membranes can be
backflushed and cleaned.
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Dead-end membrane operation
feed
permeate
Cross-flow membrane operation
feed
∆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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Spiral Wound Membrane has Multiple
Flat Sheet “leafs”
2007 EDS Conference, Halkidiki, Greece
Craig Bartels*, Mashiko Hirose, Hiroki Fujioka
*Hydranautics
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Reverse Osmosis Primarily Uses
Polyamide TFC Membranes
saline feed
posttreatment
pretreatment
high pressure pump
concentrate disposal
fresh
water
•concentration dependent,
• membranes susceptible to fouling,
RO Plant
Thin film composite membrane
• pre-treatment required,
dense polyamide membrane
porous polymer
mechanical support
• polyamide membranes degraded by Cl2.
O
NH
polyamide
H2N
O
NH
O
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


Salt rejection,
Water permeability,
Fouling (multifaceted),
Chlorine tolerance.
Salt Rejection

Normalized water permeability m3/(m2 bar day)
Journal of Membrane Science, 370(2011) 1-22.
Kah Peng Lee, Tom C. Arnot, Davide Mattia
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‣
‣
‣
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Modification of PSF substrate
•Increase hydrophilicity
Control of interfacial polymerization
•Crosslinking
•Membrane thickness
•Increase hydrophilicity
•Increased chlorine tolerance
Surface post treatment
•Modify surface charge
Membrane morphology
•Surface roughness
New thin film nanocomposite studies
•Polymer with zeolite, Ag, TiO2
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
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Materials Science has Provided Major
Breakthroughs in Water Treatment
‣
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
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Surface modification leads to decrease in contact
angle;
‣
Less fouling potential, somewhat reduced water
permeability
Contact angle (°)
‣
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
‣
Membrane degradation proceeds by
chlorination of the amide followed by
ring chlorination
Journal of Membrane Science, 300 (2007) 165-171. GuoDong Kang, Cong-Jie Gao, Wei-Dong Chen, Xing-Ming Jie,
Yi-Ming Cao, Quan Yuan
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Chlorine Tolerant Membranes Being Studied
‣
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.
‣
Microfiltration and Ultrafiltration membranes
have provided compact, efficient means of
removing suspended solids and wastewater
contaminants.
‣
Nanofiltration and RO membranes provide
lower energy alternatives for water
desalination.
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