.......

1. Presented by , Guided by,
ANOOPAANN THOMAS Dr .MARY LUBI C
GCANECH010

2.  Over 75% of the earth surface is covered in water
 97.5% of this water is salt water, leaving 2.5% as fresh water.
 Nearly 70% of the fresh water is frozen in the icecaps of
Antartica and Greenland; most of the remainder is present as soil
moisture or as groundwater not accessible to human use.
 Less than 1% of the world’s freshwater is accessible for direct
human uses.

4. Fresh water
SECTOR/PROCESS
Wastewater

5. Why wastewater treatment???
 Increasing population
 Depleting water resources
 Climate change resulting in prolonged droughts and floods.

7. Why research is still going on?????
 Day to day Change in wastewater composition
 Requirement of stable methods
 Requirement of economical methods
 Requirement of effective methods
 Search for reliable methods

8. UNSOLVED TECHNOLOGY PROBLEMS......
Mercury contamination, Minamata,
Japan, 1956
Microbial contamination,
Zimbabwe, 2009
Pesticide contamination,
Kerala, 2001
Fluoride contamination, India,
2003

9. What is nanotechnology??
The creation of functional materials ,devices and systems
through control of matter on the nanometer length scale (1-
100nm), and exploitation of novel phenomenon and properties
(physical, chemical and biological ) at that length scale.

10.  Dendrimers
 Metal nanoparticles
 Zeolites
 Carbonaceous nanomaterials

11. Dendrimers

12.  Size → 1-20 nm
 Globular shape
 Structure → 3 regions
 Dendrimers differs in structure
 Presence of interior voids
Eg: PAMAM (Polyamidoamine) dendrimers
Ethylene Diamine (EDA) core and terminal NH2 groups
can recover Cu ( II ) ions from aqueous solutions.
 Cu (II), Ni (II) and Cr (III) can be removed.

13. Metal nanoparticles
 Magnesia nanoparticles (5-100 nm): Effective biocide
against gram positive and gram negative bacteria and
bacterial spores
 Gold nanoparticles (20-100nm): Palladium coated
nanoparticles are effective catalyst for removing TCE
(Trichloroethane) from groundwater.
 Silver nanoparticles (1-40nm) : acts as an anti-microbial,
anti-biotic and anti- fungal agent

14. Zeolites
 Zeolite nanoparticles are prepared by laser- induced
fragmentation.
 An effective sorbent and ion exchange media for metal ions.

15.  Porous structure
 Can accommodate variety of cations
Na+,K+,Ca2+,Mg2+ etc.......
 These ions can be readily exchanged
 NaP1 zeolites (Na6Al6Si10O32.. 12H2O)
have a high density of Na+ ion-
exchange sites.
Experiments have reported the
successful use of synthetic NaP1
zeolites to remove Cr (III), Ni (II), Zn
(II), Cu (II) and Cd (II) from wastewater.

16. Carbonaceous nanomaterials
 High capacity selective sorbents for organic solutes
 Shows antibacterial properties
 Includes polymers like
azidated polyvinyl chloride, PEG polymer,
Polyethylene mine (PEI) etc...
 Polymers are poly cationic agents

17. HOW IT SHOWS ANTIBACTERIAL
ACTIVITY????
 Occurrence of new micro contaminants is a challenge to
mankind.
 Nanoparticles have the ability to penetrate into the cell
cytoplasm.
 Positively charged materials are absorbed on negatively charged
cell surfaces.
 Disruption of cell membranes

18. MECHANISMS OF REMOVING
POLLUTANTS
 Nanosorption
 Nanofiltration
 Photocatalysis

19. NANOSORPTION
 Nanoparticles have larger surface area.
 It can be enhanced with various reactive groups to
increase their chemical affinity towards target
compounds.
 Activated carbon is the widely used adsorbent in
conventional methods.
 Higher efficiency with the use of CNTs and metal based
nanosorbents

20. Major drawbacks of activated carbon
 Contains a significant number of micropores inaccessible to
bulky organic molecules.
 Low affinity for low molecular weight polar organic
compounds.

21. Carbon nanotubes (CNTs) & Metal nanosorbents
 From planar sheet of graphite (Graphene)
 Available surface area for adsorption on individual CNTs is their
external surfaces.
 Hydrophobicity of graphitic surface.
 Peng (2005) discovered Cerium oxide supported CNTs are
effective sorbents for arsenic .
 Nanomaterials can remove heavy metals.
 Metal based nanosorbents are used for the removal of arsenic.

22. NANOFILTRATION
 A pressure driven membrane separation process.
 Falls between ultrafiltration and reverse osmosis.
 Low pressure membrane process (7-30 bar)
 Nanofiltration membrane has pore size 1-5 nm
 Higher flux rate
 Allows the transmission of monovalent ions but multivalent ions
are largely retained.

23.  Nanofiltration membranes have been shown to remove
Turbidity
Microorganisms
Inorganic ions (Ca , Na)
Nitrates and arsenic from groundwater
Organic pollutants
 Carbon nanotube filters
 Nanoceramic filters

24. PHOTOCATALYSIS
 An advanced oxidation process
 Major barrier for its wide application is slow kinetics
 TiO2 is the most widely used photocatalyst
 Ti exists naturally in three different forms rutile, anatase,
brookite.
 Anatase is most often used in photocatalysis

25. Steps involved in degradation of organic compounds
1. External diffusion of reactant to photocatalyst surface.
2. Adsorption of contaminant.
3. Reaction of adsorbed organic compound with photo-excited
photocatalyst.
4. Desorption of reaction products.
5. Mass transfer of reaction product to bulk water.

26. How it works ???

28. ADVANTAGES OVER CONVENTIONAL METHODS
 Efficient
 Reliable
 High capacity
 Regenerative
 Stable
DRAWBACK
 Scale up is difficult
 High cost

29. CONCLUSION
The unique properties of nanomaterials and their
convergence with current treatment technologies present
great opportunities to revolutionize water and wastewater
treatment.

30. REFERENCES:
1. Sayan Bhattacharya, Indranil Saha, Anirudda Mukhopadhyay,
Dhrubajyoti Chattopadhyay,Uday Chand Gosh and Debashis
Charrerjee (2013), Role of nanotechnology in water treatment
and purification: Potential applications and implications,
International Journal of Chemical Science and Technology,
ISSN 2249-8532
2. M. T. Amin, A. A. Alazba, and U.Manzoor (2014), A Review
of Removal of Pollutants from Water/Waste water Using
Different Types of Nanomaterials, Journal of Advances in
Materials Science and Engineering, Volume 2014,Article ID:
825910
3. Karishma K. Chorawala, Mehali J. Mehta
(2015),Applications of Nanotechnology in Wastewater
Treatment, International Journal of Innovative and Emerging
Research in Engineering, Volume 2,Issue 1,ISSN:2394-5394

31. 4. Bernd Nowak (2008), Pollution Prevention and Treatment Using
Nanotechnology, Volume 2, Environmental Aspects, Edited by Harald
Krug, ISBN: 978-3-527-31735-6
5. Xiaolei Qu, Pedro J.J. Alvarez, Qilin Li (2013),Application of nano
technology in water and wastewater treatment, SciVerse Science Direct,
ISSN 3931-3946
6. Dhermendra K. Tiwari, J. Behari and Prasenjit Sen
(2008),Applications of Nanoparticles in Waste Water Treatment, World
Applied Sciences Journal 3 (3) 417-433,2008,ISSN 1818-4952
7. D.M Johnson, D.R. Hokanson, Q. Zhang, K.D.Czupinski and J.Tang
(2008), Feasibility of water purification technology in rural areas of
developing countries ,Journal of Environmental
Management,Vol.88,no.3,pp.416-427

32. Quotes!!!!
“The wars of the twenty-first century will
be fought over water “
Ismail Serageldin

33. THANK YOU
ALL!!!!

34. QUERIES