Development Of Ro Membrane & Its CharacterizationPresentation Transcript
Development of RO Membrane & Its Characterization 9/21/2010 1 Project Presentation On:
Tables Of Content History What is Reverse Osmosis? Membrane & Its types Reverse Osmosis Membranes & its comparison Membrane Materials Membrane Modules Membrane Fouling Work Plan of our Project Testing Desalination Benefits Future Aspects 9/21/2010 2 Plastic Technology Center, Karachi
The first studies on osmosis were carried out as early as 1748 by the French scientist Nollet.
The early 1960's, Loeb and Sourirajan developed a method for making asymmetric Cellulose acetate membranes
In 1970, the development of new-generation membranes such as the thin-film, composite Membrane that can tolerate wide pH ranges, higher temperatures and harsh chemical environments.
An estimate indicated that sales of RO membrane products had grown to $280 million yearly in 2006
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What is REVERSE OSMOSIS?
Osmosis is a natural phenomenon in which a solvent (usually water) passes through a semi permeable barrier from the side with lower solute concentration to the higher solute concentration side. As shown in Figure(a).
A reverse osmosis membrane acts as the semi permeable barrier to flow in the RO process, allowing selective passage of a particular species (solvent, usually water) while partially & completely retaining other species (solutes). As shown in Figure(b).
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Membrane & Its types Water treatment processes employ several types of membranes. They include
MF membranes have the largest pore size and typically reject large particles and various microorganisms.
UF membranes have smaller pores than MF membranes and, therefore, in addition to large particles and microorganisms, they can reject bacteria and soluble macromolecules such as proteins.
RO membranes are effectively non-porous and, therefore, exclude particles and even many low molar mass species such as salt ions, organics, etc.
NF membranes are relatively new and are sometimes called “loose” RO membranes
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Reverse Osmosis Membrane
Cellulose Acetate Membrane
Thin Film Composite Membrane
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These initial RO membrane was made by the Loeb-Sourirajan
These CA membranes were asymmetric and exhibited NaCl rejection values of approximately 99.5%
The degree of acetylation describes the how many pendent OH groups are replaced acetyl groups, CH3COO.
It ranges from 0 to 3
they have excellent mechanical properties & resistant to chlorine.
CA membranes can tolerate up to 5 ppm
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Thin Film Composite Membrane
The first TFC RO membrane was developed by John Cadotte at North Star Research in 1972, based on aromatic polyamides.
interfacial polymerization are use to create a polyamide coating.
Most TFC membranes are made with a porous, highly permeable support.
Nowadays, This technique can also be used to produce Commercial RO membranes
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Comparison of Reverse Osmosis Membranes 9/21/2010 Plastic Technology Center, Karachi 9
Membrane Materials 9/21/2010 10 Plastic Technology Center, Karachi
RO Membranes There are typically cellulose acetate Polysulfone coated with aromatic polyamides 9/21/2010 11 Plastic Technology Center, Karachi
MF & UF Materials Poly (vinylidene fluoride) Polysulfone Poly (acrylonitrile) Poly (acrylonitrile)-poly(vinyl chloride) copolymers Poly (ether sulfone) is also commonly used for UF membranes poly (tetrafluoroethylene). 9/21/2010 12 Plastic Technology Center, Karachi
Membranes Modules 9/21/2010 13 Plastic Technology Center, Karachi
Modules of membrane There are four main types of modules:
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Membrane fouling 9/21/2010 15 Plastic Technology Center, Karachi
Causes of Fauling Bio-fouling (it results from microbial contamination of feed water) Scaling (It arises from the deposition of salts) Organic (It comes from substances i.e. C-H which coat the surface) Colloidal (It mainly stems from particles) 9/21/2010 16 Plastic Technology Center, Karachi
Work Plan of Project 9/21/2010 Plastic Technology Center, Karachi 17
Strategy of Work Plan MARKET SURVEY TO FIND THE AVAILBILITY OF MATERIALS STUDY AND ANALYZE ABOUT RO PROCESS TECHNOLOGY CONSULT THE RELEVANT AUTHORITIES / ORGANIZATION DEVELOPMENT OF RO MEMBRANE SAMPLES TESTING OF MEMBRANE SAMPLES 9/21/2010 Plastic Technology Center, Karachi 18
Testing of Membranes 9/21/2010 Plastic Technology Center, Karachi 19
Major Tests of Membranes Non-Destructive Tests: Bubble test- test physical integrity of the membrane envelope Membrane performance - flux, pressure and percent reject Analysis of cleaning solution Destructive Tests: Internal visual exam Coupon testing of membrane surface Metals analyses Digestion Organic Analyses: FTIR Spectroscopy UV Spectroscopy 9/21/2010 Plastic Technology Center, Karachi 20
Desalination 9/21/2010 21 Plastic Technology Center, Karachi
Benefits & Applications of Membrane 9/21/2010 Plastic Technology Center, Karachi 23
CA membranes will reduce the cost of RO treatment processes RO processes are used in the production of food and beverages, pharmaceuticals, and chemical products. a new alternative to many areas where drinking water is in short supply. RO technologies can make use of use an almost unlimited and reliable water source, the sea. RO has a negligible environmental impact RO technologies can be used to remove organic and inorganic contaminants. Most economical process for salinity reduction associated with secondary effluent (or other wastewater source) TDS levels. 9/21/2010 Plastic Technology Center, Karachi 24
Future Aspects 9/21/2010 Plastic Technology Center, Karachi 25
Development of membranes that is less prone to fouling, operate at lower pressures, and require less pretreatment of the feed water. Membranes able to remove hydrocarbons and salt could turn produced water. Reduced fouling would make membranes even more cost effective by extending their operational lifetime. focused on surface modification of membranes and increasing the pretreatment of the feed water. Development of more energy-efficient technologies that are simpler to operate than the existing technology 9/21/2010 Plastic Technology Center, Karachi 26
“End of Presentation”DESIGNED BY: Adeel Fayyaz (12 – PE – 01) Rehan Hasan (12 –PE – 33) Zohaib Siddiqui(12 – PE – 44) 9/21/2010 Plastic Technology Center, Karachi 27