potable water purification and Solar disinfection it include that how to purify water by chemical and solar methods

1. Portable water purification
and
Solar disinfection
Izhar Ul Haq Izhar
2nd Year BDS KCD
Peshawar
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2. Objectives:
 By the end of this presentation my class fellows will
be able to know about “Portable water purification
and solar disinfection”.
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3. Contents
 Definition of water purification.
 Portable water purification and its methods.
 Solar disinfection.
 History of solar water disinfection.
 How solar water disinfection (SODIS) works.
 Advantages and disadvantages of “SODIS”.
 Summary.
 References.
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4. Water Purification
The process by which undesired chemical compounds,
organic and inorganic materials, and biological
contaminants are removed from water is called water
purification.
Purification procedure reduces the concentration of
contaminants such as:
Suspended particles,
Parasites,
Bacteria etc.
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5. Potable water
 The water that is safe to be used as
drinking water
“OR”
 Water that is suitable for human
consumption i.e.
 Drinkable
 Safe
 Food preparation
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6. Portable water purification:
 The word “portable” means “to carry”.
Portable water purification system are self-contained ,
easily transported used to purify water from untreated
sources for drinking purposes.
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7. Continue
It is used for hiking , camping and travel in
remote areas.
They are also called “ point-of-use (POU) water
treatment” or “ field water disinfection”.
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8. Methods of portable water purification
Portable water purification can be done through;
1) Portable pump filter.
2) Chemical additives.
a) Chlorine dioxide.
b) Iodine solution.
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9. 1) Portable pump filters
 They are typically made of either ceramic or
fiberglass.
 The pores on these filters are small enough to let
water molecules pass through, but block bacteria
(like E coli) and protozoa etc.
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10. 10
Portable pump filters

11. 2) Chemical additives:
a) Chlorine dioxide:
 It is commonly used to disinfect drinking
water.
 It is used in very small quantities for
disinfection.
 It is very irritating to the respiratory tract if
use in large quantity.
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12. Continue
 Chlorine dioxide kills Cryptosporidium and
Giardia.
 It reacts quickly.
 Improves the taste and odor of water.
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13. b) Iodine:
 Iodine (In solution or Tablets form) is use for water
purification because it,
 Kills most viruses and bacteria with little effort.
 Less expensive.
 Easy to pack and carry.
 Easy to use.
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14. Solar water disinfection:
Definition:
 The method of using temperature and UV radiation
of sunlight to inactivate or destroy microbes in
biologically contaminated water.
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15. History of solar water disinfection
The principle of water disinfection by solar
radiation was first discovered in 1984 by
Prof. Aftim Acra of the American University
in Beirut.
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16. Continue
In the 1990s, researchers launched extensive
laboratory studies to evaluate the potential of solar
radiation to inactivate bacteria and viruses. Based
on the findings of these experiments, they designed
a standard procedure – the SODIS method.
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17. How solar water disinfection Works:
Fill the transparent plastic bottle with water. Shake for
20 second to oxygenate.
Usually the bottle is placed on tile or metal, but can be
anywhere in the sunlight.
6 hours is the proper duration in direct sunlight. But
depend on intensity of sunlight.
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18. Continue
UV radiation cause the damage of bacterial
DNA and proteins.
Polyethylene terephthalate(PET) bottle should
be used.
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19. Efficacy
The disinfection efficacy of the SODIS method
depends on a number of factors:
Type and origin of pathogenic organism
Radiation intensity
Place and position of bottle exposure
Turbidity and dissolved organic matter
Oxygen content
Water temperature
Re-growth of pathogen
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20. Advantages of Solar water disinfection
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1: Simple and safe method.
2: Acceptability by users because of simplicity.
3: No cost after obtaining plastic bottles.
4: Water still tastes fresh.
5: Bottles can be left on any surface.
6: If unopened, bottles can be stored indefinitely.
7: Proven reduction of viruses, bacteria, and
protozoa in water.

21. Disadvantages of Solar water disinfection
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1: Need pretreatment of water with high turbidity.
2: Length of time.
3: Cannot use water that has been polluted with
chemicals.
4: Can only use clear bottles.
5: Older or scratched bottles reduce effectiveness.
6: Bottles create waste.
7: Cannot treat in larger bottles.

22. Summary
Water purification : The process of removing undesirable
substances from water.
Portable water purification: Water purification system
which is easy to carry
Methods : Portable Pump filter, ClO2,Iodine methods.
Solar Water Disinfection : Method of microbial
inactivation by using sunlight.
Advantages: Safe, Acceptable , No cost , Fresh taste.
Disadvantages : Need pretreatment , More time , create
waste etc.
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23. References
Textbook of “Public Health Dentistry” Third Edition By SS
Hiremath. Chapter No 3 by Prithvish and K Pushpanjali
(Page No 44 and 45) (Date 28 Feb 2022 Time 8:30 pm)
https://www.slideshare.net (Date 2 Mar 2022 Time 4:00 pm)
https://www.sodis.ch/sodismanual_2016.pdf
http://en.m.Wikipedia.org/ (Date 5 Mar 2022 Time 10:45 am)
Sir Dr Manzar Anwar lecture
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