04/11/2023 1

Development of RO Membrane & Its Characterization

Project Presentation On:

04/11/2023 Plastic Technology Center, Karachi 2

Tables Of ContentHistoryWhat is Reverse Osmosis?Membrane & Its typesReverse Osmosis Membranes & its comparisonMembrane MaterialsMembrane ModulesMembrane FoulingWork Plan of our ProjectTestingDesalinationBenefits Future Aspects

04/11/2023 Plastic Technology Center, Karachi 3

HistoryThe 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

04/11/2023 Plastic Technology Center, Karachi 4

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).

04/11/2023 Plastic Technology Center, Karachi 5

Membrane & Its typesWater 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

04/11/2023 Plastic Technology Center, Karachi 6

Reverse Osmosis MembraneCellulose Acetate MembraneThin Film Composite Membrane

04/11/2023 Plastic Technology Center, Karachi 7

CA MembraneThese 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

04/11/2023 Plastic Technology Center, Karachi 8

Thin Film Composite MembraneThe 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

04/11/2023 Plastic Technology Center, Karachi 9

Comparison of Reverse Osmosis MembranesCA Membranes TFC Membranes

Rejection of Organic Low High

Rejection of low mol. weight organics

Low High

Water Flux Medium High

pH Tolerance 4-8 2-11

Temperature stability Max. 35c Max. 45c

Oxidant tolerance High Low

Compaction tendency High Low

Biodegradability High Low

Cost Low High

04/11/2023 Plastic Technology Center, Karachi 10

Membrane Materials

04/11/2023 Plastic Technology Center, Karachi 11

RO MembranesThere are typically

cellulose acetatePolysulfone coated with aromatic polyamides

04/11/2023 Plastic Technology Center, Karachi 12

MF & UF MaterialsPoly (vinylidene fluoride)PolysulfonePoly (acrylonitrile)Poly (acrylonitrile)-poly(vinyl chloride) copolymersPoly (ether sulfone) is also commonly used for UF

membranespoly (tetrafluoroethylene).

04/11/2023 Plastic Technology Center, Karachi 13

Membranes Modules

04/11/2023 Plastic Technology Center, Karachi 14

Modules of membraneThere are four main types of modules:

plate-and-frame

Tubular

spiral wound

hollow fiber

04/11/2023 Plastic Technology Center, Karachi 15

Membrane fouling

04/11/2023 Plastic Technology Center, Karachi 16

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)

04/11/2023 Plastic Technology Center, Karachi 17

Work Plan of Project

04/11/2023 Plastic Technology Center, Karachi 18

Strategy of Work PlanMARKET 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

04/11/2023 Plastic Technology Center, Karachi 19

Testing of Membranes

04/11/2023 Plastic Technology Center, Karachi 20

Major Tests of Membranes Non-Destructive Tests:1. Bubble test- test physical integrity of the membrane envelope 2. Membrane performance - flux, pressure and percent reject 3. Analysis of cleaning solution

Destructive Tests:1. Internal visual exam2. Coupon testing of membrane surface3. Metals analyses4. Digestion

Organic Analyses:1. FTIR Spectroscopy2. UV Spectroscopy

04/11/2023 Plastic Technology Center, Karachi 21

Desalination

04/11/2023 Plastic Technology Center, Karachi 22

Desalination Techniques Multi-effect distillation (MED)Multi-stage flash (MSF)Reverse osmosis (RO)Electro dialysis (ED)Capacitive deionization (CDI)Mechanical vapor compression (MVC)

04/11/2023 Plastic Technology Center, Karachi 23

Benefits & Applications of Membrane

04/11/2023 Plastic Technology Center, Karachi 24

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.

04/11/2023 Plastic Technology Center, Karachi 25

Future Aspects

04/11/2023 Plastic Technology Center, Karachi 26

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

04/11/2023 Plastic Technology Center, Karachi 27

“End of Presentation”

DESIGNED BY:Adeel Fayyaz (12 – PE – 01)Rehan Hasan (12 –PE – 33)Zohaib Siddiqui(12 – PE – 44)