application of nanotechnology

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BASICS OF NANOSCIENCES
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GROUP MEMBERS

• MAIMOONA AHSAN
• HANNAN ALTAF
• SOBIA SHAHZADI
• HAFSA QAYYUM
• ZAINAB MALIK
• HUMA ABBASI

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TOPIC OF PRESENTATION

• WATER PURIFICATION AND NANOTECHNOLOGY

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WHAT IS NANOTECHNOLOGY?

• NANOTECHNOLOGY IS THE MANIPULATION OF MATERIAL AT
  THE NANOSCALE TO TAKE ADVANTAGE OF THESE
  PROPERTIES. THIS IS OFTEN MEANS WORKING WITH
  INDIVIDUAL MOLECULES.

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LESS AVAILABILITY OF DRINKING WATER

• Over 75 0f Earth Surface Is Covered With Water.
• 97.5 Of This Water Is Salt Water Leaving Only
  2.5 As Fresh Water.
• And Only 1 Of The World Fresh Water Is
  Accessible For Direct Human Uses.

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WHAT IS WATER PURIFICATION?

• IT IS A METHOD TO REMOVE CHEMICAL MATERIAL AND
  CONTAMINANTS TO PRODUCE CLEAN AND FRESH DRINKING
  WATER.

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WATER RELATED INFECTIOUS DISEASES
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Water Borne Diseases When People Consume Water
Contaminated By Human Or Animal Feces Water
Washed Diseases Infections Caused By Poor
Personal Hygiene Or Lack Of Water
Availability Water Based Diseases Transmitted By
Aquatic Organisms Entering The Body When
Contaminated Water Is Used For Drinking Or
Bathing Water Related Insect Vector
Diseases Spread Through Insects Infecting
Someone's Blood Defective Sanitation Water
Containing Toxins Such As Arsenic, Fluoride, And
Chlorine
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CONVENTIONAL METHOD USED FOR WATER PURIFICATION

• FILTERATION
• SEPARATES SOLIDS FROM FLUIDS
• SEDIMENTATION
• PARTICLES SETTLING OUT OF LIQUIDS AGAINST A
  BARRIER
• BIOLOGICAL PROCESSES
• REMOVING LIVING ORGANISM
• DISALINATION
• REMOVING SALTS AND OTHER MINERALS
• CHEMICAL PROCESSES
• REMOVING CHEMICAL COMPOUNDS
• MECHANICAL FILTERATION
• SCREENING THE MATERIALS

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Advanced types of Mechanical Filtration

• Some methods of mechanical filtering are actually
  capable of doing so on the nano-metre scale
• i.e. Diatom filtration
• Reverse Osmosis

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Diatom Filtration

• SEM Micrographs Of Diatoms
• Diatoms Are Small Single-celled Marine Algae That
  Use Silica To Form Hard Shells. They Have Small
  Pores That Allow The Flow Of Nutrients.
• A-D- Examples Of Diatom Morphologies (Scale 10µm)
• E- Valve Openings (Scale 1µm)
• Due To Their Small Size And Hard Shells They Can
  Be Packed Together To Form Compact Filters
  Capable Of Filtering Objects On The Micron Scale
• Unfortunately Due To The Relatively Large Size Of
  Their Pores They Are Incapable Of Removing
  Chemical Impurities.

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Reverse Osmosis

• Pressure Is Applied Across A Membrane, Driving
  Pure Water Across While Leaving Concentrate
  Behind
• Drawbacks
• Most Of The Water Wasted 87
• High Pressures Are Needed To Maintain Flow
• Membrane Rapidly Loses Efficany.

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NANOTECHNOLOGY AND WATER PURIFICATION
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Carbon Nanotubes -Nanosize Cylinder Carbon Atoms
That Provide The Basis For Nano filtration And
Nano reactive Membranes, Aiding The Filtration
Process. -Removes Bacteria And Viruses. Titanium
Dioxide Nanoparticles -With Ultraviolet Lights,
They Have Improved Total Removal Of Organic
Carbon. Nanofiltration Membranes -Removes
Dissolved Salts And Pollutants By A Physical
Barrier. -Softens Water. Nanorust -Magnetic
Nanoparticles Of Iron Oxide Suspended In Water To
Remove And Bind Arsenic. Desalination
Membranes -Combination Of Polymers And
Nanoparticles To Draw In Water Ions And Repel
Salts.
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World Filter -Nanofibre Layer Of Polymers,
Resins, And Ceramic To Remove Contaminants Nanome
sh Water stick -Straw Like Filtration Device
Using Carbon Nanotubes To Filter As You
Drink Pesticide Filter -Nanosilver To Absorb And
Break Down Pesticides
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ROLE OF NANOTECHNOLOGY IN WATER PURIFICATION

• TREATMENT AND REMEDIATION
• SENSING AND DETECTION
• POLLUTION AND PREVENTION

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NANOTECH SOLUTIONS

• USE OF NANOTUBES IN FILTERING DEVICES.
• USE OF NANOPARTICLES AS TREATMENT AGENTS.

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NANOTUBES FILTERS
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The Use Of Carbon Nano-tubes As Filtering Devices

• A. Schematic Of The Process
• B. Photograph Of The Bulk Tube.
• C. SEM Image Of The Aligned Tubes With Radial
  Symmetry Resulting In Hollow Cylindrical
  Structure (Scale 1 Mm).

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How The Filter Works?

• The Nano-tubes Act As A Kind Of Molecular Filter,
  Allowing Smaller Molecules (Such As Water) To
  Pass Through The Tubes, While Contaminants Are
  Too Large To Pass Through.
• Due To Their Electronic Configuration
• Smaller Ions That Would Otherwise Pass Through
  Are Also Blocked.

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Removal Of Bacteria Using Nanotube Filter

• A, The Unfiltered Water Containing E. Coli
  Bacteria
• B, The E. Coli Bacteria (Marked By Arrows) Grown
  By The Culture Of The Polluted Water
• C, The Filtration Experiment
• D, The Water Filtered Through Nanotube Filter
• E, The Filtrate After Culture Showing The
  Absence Of The Bacterial.

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ADVANTAGES OF USING NANOTUBES

• Much Less Pressure Required To Move Water Across
  Filter.
• Much More Efficient.
• Filter Easily Cleaned By Back Flushing.
• Selective Adsorption Properties Of Nanotube
  Surfaces.
• Incredibly Large Surface Area.
• Manmade Nanotube Membranes Allow Fluid Flow
  10,000 To 100,000 Times Faster Than Conventional
  Fluid Flow.

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WATER TREATMENT USING NANOPARTICLE

1. NANOFILTRATION
2. CATALYTIC DEGRADATION OF WATER POLLUTANTS
3. ADSORPTION OF POLLUTANTS
4. MAGNETIC NANOPARTICLES
5. NANOSENSORS

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NANOFILTRATION

• NF MEMBRANES ARE PRESSURE DRIVEN MEMBRANES WITH
  PROPERTIES BETWEEN THOSE OF REVERSE OSMOSIS AND
  ULTRFILTRATION MEMBRANES AND HAVE PORES SIZE
  BETWEEN 0.2 AND 4nm.
• NF MEMBRANES ARE USED IN WATER TREATMENT FOR
  DRINKING WATER PRODUCTION OR WASTEWATER
  TREATMENT.
• NF MEMBRANES ARE USED TO REMOVE TURBIDITY,
  MICROORGANISM AND INORGANIC IONS SUCH AS Ca and
  Na.
• THEY ARE USED FOR SOFTENING OF GROUND WATER.

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CATALYTIC DEGRADATION OF WATER POLLUTANTS

• Nanoparticles Are Used As Nanocatalyst.
• Nanocatalysts Owe Their Better Catalytic
  Properties To Their Nanosize Or To Being Modified
  At The Nanoscale. They Can Chemically Degrade
  Pollutants Instead Of Simply Moving Them
  Somewhere Else, Including Pollutants For Which
  Existing Technologies Are Inefficient Or
  Prohibitively Expensive.

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ADSORBANTS OF POLLUTANTS

• Sorbants Are Widely Used In Water Treatment And
  Purification To Remove Organic And Inorganic
  Contaminants For Example Activated Carbons And
  Ion Exchange Resins.
• The Unique Structure And Electronic Properties Of
  Some Nanoparticles Can Make Them Specially
  Powerful Adsorbants.

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NANOSENSORS

• Nanosenors For The Detection Of Contaminants And
  Pathogens Can Improve Health Maintain A Safe Food
  And Water Supply, Allow For The Use Of Otherwise
  Unusable Water Sources.
• The System Could Be Used To Analyze Chemicals And
  Bacteria In Water.

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MAGNETIC NANOPARTICLES

• Magnetic Nanoparticles Have Large Surface Areas
  Relative To Their Volume And Can Easily Bind With
  Chemicals. In Water Treatment Applications, They
  Can Be Used To Bind With Contaminants Such As
  Arsenic Or Oil And Then Be Removed Using A
  Magnet.

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ADVANTAGES OF USING NANOTECHNOLOGY IN WATER
PURIFICATION

• CONTRIBUTES TO LONG TERM WATER QUALITY,
  AVAILABILITY, VIABILITY.
• ALLOWS MORE WATER REUSE AND RECYCLING.
• SENSORS AND DETECTS BIOLOGICAL AND CHEMICALS
  CONTAMINANTS.
• USE IN MAKING DISTILLED WATER.
• REDUCED COST.

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RISKS OR DISADVANTAGES
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NANOPARTICLES ARE BECOMING A TOXIC CONCERN -They
react differently from when in original, bulk
form -Small sizes could contaminate and even
escape
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CONCLUSION

• Nano-technology Could Potentially Lead To More
  Effective Means Of Filtration That Not Only
  Remove More Impurities Than Current Methods But
  Do So Faster, More Economically And More
  Selectively.

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