reverse osmosis
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general information about reverse osmosisTRANSCRIPT
WASTE AND ENVIRONMENTAL MANAGEMENT IN PETROCHEMICAL INDUSTRIES
CPE 681
MEMBRANE APPLICATION: REVERSE OSMOSIS, MICROFILTRATION AND ELECTRO
DIALYSISGROUP MEMBERS:
NURUL FAHADA BINTI SAARI 2011278488ANIS FARHANAH BINTI MOHD SUHAIMI YEONG 2011635218MUHAMMAD AFIQ BIN MOHD HAFEEZ 2011814658
INTRODUCTION1. Pressure-driven operations• Microfiltration• Ultrafiltration• Nanofiltration• Reverse osmosis
2. Concentration-driven operations• Dialysis• Pervaporation• Forward osmosis• Artificial lung• Gas separation
3. Operations in electric potential gradient• Electrodialysis• Membrane electrolysis• Electrodeionization• Electrofiltration• Fuel cell4. Operations in temperature gradient• Membrane distillation
Membrane Distillation
Membrane Materials
Commonly used membrane : Polymers Metal membrane Ceramic membranes (metal oxide, carbon, glass) Liquid membranes
Microfiltration
A type of physical filtration process A contaminated fluid is passed through a special pore-
sized membrane To separate microorganisms and suspend particles from
the process
Electrodialysis
Electrodialysis is a separation process using a stack of alternating anion- and cation-selective membranes separated by spacer sheets.
Water is passed through the stack of membranes. Electrical current is applied to the cell, causing the anions
to migrate in one direction and the cations in the other direction.
Reverse Osmosis
Water purification technology that uses a semipermeable membrane to remove larger particles from drinking water.
An applied pressure is used to overcome osmotic pressure. Hence, called the reverse osmosis.
How it works?
Membrane Process Characteristics
Reverse Osmosis
Reverse Osmosis
Exert hydraulic pressure which more than the osmotic pressure (natural diffusion of water)
Diffusion of water into less concentrated section, left the particles behind. http://www.geafiltration.com/technology/reverse_osmosis_flash.as
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Microfiltration
Nanofiltration
Ultrafiltration Microfiltration
Its like “sieve” membrane filtration and differs on its pore size
Electrodialysis
Ions are transported through semipermeable membranes under the influence of an electric field
Two different solution generated in this process One dilute and other concentrate
Electrodialysis (cont’)
Differences in Properties Properties
Reverse Osmosis Microfiltration Electro dialysisPore Size <0.0001 0.01-1.0 <10
Molecular Weight Cutoff 100-300 >100,000 -
Operating Pressure 225-1000 psi <30 psi Electrical potential
Membrane Materials Cellulose acetate, thin film composite, polysulfonated polysulfone.
Ceramics, polypropylene, polysulfone, polyvinylidenediflouride.
Membrane made of cation or anion selective matter.
Membrane Configuration Tubular, spiral wound, plate and frame.
Tubular, hollow fiber. Multiple membrane in a row which have alternate configuration to allow positively or negatively charged ion to flow through.
Types of material removed Metal cations, acids, sugars aqueous salts, amino acids, monovalent salts, BOD, COD.
Clay, bacteria, viruses, suspended solids.
Removal of ion from wastewater.
Electro dialysis vs ElectrolysisElectro dialysis Electrolysis-Use ion permeable membrane to separate between two charged plates of the ionization chamber.-anode and cathode plates are in separate compartments.-Acidic water and alkaline water is separated.
-Anode and cathode are in the same chamber.-the alkaline water from cathode plate and acidic water from anode plate are not separated.
Microfiltration vs Ultrafiltration vs Nano filtration
Microfiltration Ultrafiltration Nano filtration-Served as pre-treatment for other separation process such as ultrafiltration.-To prevent particle such as sediment, algae, protozoa or large bacteria.
-Use for pretreatment of water for nano filtration or reverse osmosis.
-Technique use to remove two valued ion and larger mono valued ions.
Reverse Osmosis vs Forward Osmosis
Reverse Osmosis Forward Osmosis-Require pressure to push water into semi permeable membrane to remove large majority of contaminant.
-Does not require external pressure to push solution through membrane.-Water diffuses spontaneously from low osmotic pressure solution to solution with high osmotic pressure.
ApplicationsTypes of membrane ApplicationReverse Osmosis -Treatment for industrial
wastewater-Drinking water-Desalination
Microfiltration -Pharmaceutical process.-Oil purification-Regenerate based oil from used oil.
Electro dialysis -Separation of inorganic and organic solutions.-Wine stabilization-Purifications of salty mine waters
Forward Osmosis -Waste water treatment-Food processing-Water desalination