If nanotechnology is to represent societal as well as technical progress, It will have to contribute to the solution of global problems such as water quality. Providing clean and affordable water to meet human needs is a grand challenge of the 21st century. Worldwide, water supply struggles to keep up with the fast growing demand, which is exacerbated by population growth, global climate change, and water quality deterioration. The need for technological innovation to enable integrated water management cannot be overstated. Nanotechnology holds great potential in advancing water and wastewater treatment to improve treatment efficiency as well as to augment water supply through safe use of unconventional water sources. Given the importance of clean water to people in developed and developing countries, numerous organizations are considering the potential application of nanoscience to solve technical challenges associated with the removal of water contaminants. Technology developers and others claim that these technologies offer more effective, efficient, durable, and affordable approaches to removing specific types of pollutants from water. A range of water treatment devices that incorporate nanotechnology are already on the market and others are in advanced stages of development. These nanotechnology applications include: • Nanofiltration membranes, including desalination technologies; • Attapulgite clay, zeolite, and polymer filters; • Nanocatalysts; • Magnetic nanoparticles; and • Nanosensors for the detection of contaminants

1. WATER POLLUTION PREVENTION
AND
TREATMENT USING NANOTECHNOLOGY
By:
Name : Kavaiya Ashish Rajeshkumar
Roll No:U10CH010
Guide : Dr.Z.V.P. Murthy
Chemical Engineering Department,
Sardar Vallabhbhai National Institute of Technology,
Surat-395007

2. Introduction :
Today Availabilty of claen,abundant fresh water for human use is among the
most pressing issues in the world.
More than One Billion people In the World lack access to clean water, and
things are getting worse.
Nanotechnology encompasses a broad range of tools, techniques, and
applications and is widely perceived as one of the most significant
technologies of the 21st century.
Nanomaterials are manufactured materials with a structure between
approximately 1 nanometer (nm) and 100 nm.Their unique
physicochemical (e.g., size, shape) and surface (e.g., reactivity,
conductivity) properties contribute to the development of materials with
novel properties and technical solutions to problems that have been
challenging to solve with conventional technologies.
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3. Water purification using nanotechnology exploits nanoscopic materials
Fullerenes
NanoParticles
Composed entirely of Carbon.
Metallic, ceramic or inorganic.
Tube shaped
Dimensions 1-100nm.
Bucky balls.
Large surface area, very reactive.
Nanotubes.
Exhibit interesting mechanical, magnetic,
optical, chemical properties.
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Carbon nanotubes.
Borosilicate glass nanoparticles.

4. Pollution Prevention by Nanotechnology
A reduction in the use of
 Raw materials,
 Water
 other resources
The elimination or reduction of waste and on the other hand to more efficient use
of energy or involvement in energy production.
The implementation of green chemistry principles for the production of
nanoparticles and for nanotechnological applications in standard chemical
engineering will lead to a great reduction in waste generation, less hazardous
chemical syntheses, improved catalysis and finally an inherently safer
chemistry.
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5. Water Treatment
1. Nanofiltration
2. Catalytic Degradation of Water Pollutants.
3. Adsorption of Pollutants
4. Magnetic Nanoparticles
5. Nanosensors
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6. 1.Nanofiltration:
NF membranes are pressure-driven membranes with properties between those
of reverse osmosis and ultrafiltration membranes and have pore sizes between 0.2
and 4 nm.
Nanof iltration membranes (NFmembranes) are used in water treatment for
drinking water production or wastewater treatment
 NF membranes have been shown to remove turbidity, microorganisms and
inorganic ions such as Ca and Na.
They are used for softening of groundwater (reduction in water hardness), for
removal of dissolved organic matter and trace pollutants from surface water, for
wastewater treatment (removal of organic and inorganic pollutants and organic
carbon) and for pretreatment in seawater desalination.
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7. Seawater Desalination using Nanofiltration Method –
The Long Beach Method
Seawater filtered to remove suspended solids.
Stage 1: Filtered seawater pumped under
high pressure through nanofiltration
membrane.
Only smallest 12% of salt molecules pass
through
Stage 2: Water from Stage 1 is pumped
under lower pressure through second
nanofiltration
Membrane.
Blocks passage of almost all remaining salts.
High quality potable water produced.
Energy savings:
Traditional desalination
method pressure
required for pumping:
1000pounds per square
inch(psi).
Long Beach Method:
525psi first stage, 250psi
second stage.
Energy savings: 20-30%
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Pilot plant running from 2001.

8. 2. Catalytic Degradation of Water Pollutants
Nanoparticles serve as catalysts.
Chemically degrade pollutants.
Nano titanium-dioxide particles for degrading organic as well inorganic pollutants.
In water, photo-oxidation occurs primarily through hydroxyl radicals. Because
TiO2 requires ultraviolet light for excitation, it has been sensitized to visible
light by dyes, through incorporation of transition metal ions or by doping with
nitrogen .
Nanoscale zerovalent Fe0 & bimetallic Fe0 detoxify organic & inorganic
pollutants in aqueous solutions.
Nanoscale zerovalent iron (nZVI) can reduce not only organic contaminants
but also the inorganic anions nitrate, which is reduced to ammonia, perchlorate
(plus chlorate or chlorite), which is reduced to chloride, selenate, arsenate,
arsenite and chromate .
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9. Soil and Groundwater Remediation by nZVI
Granular ZVI in the form of reactive barriers has been used for many years at numerous
sites all over the world for the remediation of organic and inorganic contaminants in
groundwater .
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10. With nZVI, two possible techniques are used:
1. Immobile nZVI is injected to form a zone of iron particles
adsorbed on the aquifer solids
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11. 2. Mobile nZVI is injected to form a plume of reactive Fe particles that
destroy any organic contaminants that dissolve from a DNAPL (dense nonaqueous phase liquid)source in the.
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12. 4. Magnetic Nanoparticles
Magnetic nanoparticles offer advantages over non-magnetic nanoparticles
because they can easily be separated from water using a magnetic field.
 Separation using magnetic gradients, the so-called high magnetic gradient
separation (HGMS), is a process widely used in medicine and ore
processing.
This technique allows one to design processes where the particles not only
remove compounds from water but also can easily be removed again and
then be recycled or regenerated.
This approach has been proposed with magnetite (Fe3O4), maghemite (gFe2O3) and jacobsite (MnFe2O4) nanoparticles for removal of chromium
(VI) from wastewater.
Water-soluble CNTs have been functionalized with magnetic iron
nanoparticles for removal of aromatic compounds from water and easy
separation from water for re-use.
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13. 3. Adsorption of Pollutants
Sorbents are widely used in water treatment and purification to remove
organic and inorganic contaminants. Eg.activated carbon and ion-exchange
resins .
The unique structure and electronic properties of some nanoparticles can
make them especially powerful adsorbents
The removal of metals and other inorganic ions, mainly nanosized metal oxides but
also natural nanosized clays have been investigated
Chemically modified nanomaterials have also attracted a lot of attention,
especially nanoporous materials dues to their exceptionally high surface area.
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14. 5. Nanosensors
Nanosensors are any biological, chemical, or surgical sensory points used to
convey information about nanoparticles to the macroscopic world.
Nanosensors for the detection of contaminants and pathogens can
improve health, maintain a safe food and water supply, and allow for the
use of otherwise unusable water sources.
New sensor technology combined with micro- and nanofabrication
technology is expected to lead to small, portable, and highly accurate
sensors to detect chemical and biochemical parameters.
BioFinger is developing a handheld device that incorporates nano- and
microcantilevers on a microchip.
The system could be used to analyze chemicals and bacteria in water.
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15. Product
How it works
Importance
Developers
Nanorust to remove
Magnetic
India, Bangladesh
Rice University,
arscenic
nanoparticles of iron
and other developing
United States.
oxide suspended in
countries suffer
water bind arscenic,
thousands of cases of
which is then
arscenic poisoning
removed with a
each year, linked to
magnet
poisoning of wells.
Desalination
A combination of
Already in the
University of
membrane
polymers and
market, this
California, Los
nanoparticles that
membrane enables
Angeles and
draws in water ions
desalination with
NanoH2O
and repels dissolved
lower energy costs
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salts.
than reverse osmosis.

16. Product
How it works
Importance
Developers
Nanofiltration
Membrane made up of
Field tested to treat
Sachen Industries,
Membrane
polymers with a pore
drinking water in China
Korea.
size ranging from 0.1-
and desalinate water in
10nm
Iran. Using this membrane
requires less enrgy than
reverse osmosis.
Nanomesh waterstick
A straw like filtration
The waterstick cleans the
device that uses carbon water as it is drunk.
nanotubes plaed on a
a prototype and the final
material.
, United States.
Doctors in Africa are using
flexible, porous
Seldon Laboratories
product is said to be
available at an affordable
cost in developing
countries.
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17. Product
How it works
Importance
Developers
World Filter
Filter using a
Designed specifically for
KX Industries, US
nanofibre layer, made the household or
up of polymers,
community level use in
resins, ceramics and
developing countries. The
other materials that
filters are effective, easy to
remove contaminants. use and require no
maintenance.
Pesticide Filter
Filter using
Pesticides are often found in Indian Institute of
nanosilver to adsorb
the developing countries
and then degrade
water supply. This pesticide Chennai, India and
three pesticides
filter can provide a typical
commonly found in
Indian household with 6000 Limited, India.
the Indian water
liters of clean water in one
supplies.
year.
Technology,
Eureka Forbes
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18. Nanotechnology to water treatment devices appears to be driven by
several factors including, but not limited to,
Reduced costs,
Improved ability to selectively
Remove contaminants,
Durability, and size of device.
Proper studies are to be carried out to assess any harmful effects on
environment and living beings.
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19. And Last…
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20. References :
[1] P. Gleick, The World's Water—The Biennial Report on Freshwater
Resources , Pacifi c Institute, Oakland, California, 1998, p. 40.
[2] B. Nowack, “Pollution Prevention and Treatment Using Nanotechnology,”
Environmental Aspects, ISBN: 978-3-527-31735-6, Date 15 JUL 2010
[3]T.Hillie, M.Munasinghe, M.Hlope, Y. Deraniyagala, “Nanotechnology,Water &
Development,” http://www.merid.org/~/media/Files/Projects/nanowaterworkshop/NanoWaterPaperFinal.ashx ,July 2010
[4] S. C. Chang, P. Adriaens , “Nano-Immunodetection and Quantification of
Mycobacteria in Metalworking Fluids,” Eng. Sci. 2007, 24, 58.
[5] N. Savage, M. Diallo, J. Duncan, A. Street, R. Sutich, Nanotechnology
Applications for Clean Water, New York: William Andrew Inc.2009
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