This document discusses using solar energy for wastewater treatment. Some key advantages of solar energy for this purpose are that it is pollution-free, requires no fuel, and produces clean energy. The document outlines various physical, chemical, and biological wastewater treatment methods and describes how solar energy can be used to power treatment plants, heat water, and enable processes like solar catalytic oxidation and solar distillation. Stabilization ponds are also discussed as a biological treatment method that can use solar energy and produce biogas as a useful byproduct.

1. Wastewater treatment
through the use of solar energy –
- P. Yuvarajan
Wastewater
treatment through
the use of

2. • Radiant energy emitted from sun

3. Advantages:
• Pollution free and causes no greenhouse gases to be
emitted after installation
• No need for fuel
• Clean energy
• Simple system configuration
• Easy maintenance
• Solar can be used to heat water, power homes and building,
even power cars
• Safer than traditional electric current

4. Disadvantages
• High initial costs
• Needs lots of space
• No solar power at night so there is a need for a
large battery bank
• Cloudy days do not produce much energy
• Lower production in the winter months

5. Wastewater
Combination of water-carried wastes
• Removed from residences and
institutions
• Created by commercial and
industrial activity

6. wastewater treatment methods
Physical
Chemical
Biological

7. Physical
• Screening
• Mixing
• Flocculation and coagulation
• Sedimentation
• Filtration

8. Chemical
Remove or convert the contaminants by
adding chemicals or through chemical
reactions.

9. Biological
• To remove the biodegradable organic
substances (colloidal or dissolved)
• Substances are converted into gases that can
escape to the atmosphere or into biological
cell tissues that can be removed by settling.
• To remove pathogens and nitrogen from
wastewater

10. Biological treatment
processes are
The principal applications for these
processes are removing carbonaceous organic
matter (measured in BOD, COD, or in TOC),
nitrification, denitrification, or stabilization.

11. Stabilization Ponds
• Treat a wide variety of domestic and
industrial wastes.
• Stabilization ponds can also be used to
convert the emitted gases into useful energy.
• The biogas produced from the biological
processes can be collected and used to
produce energy (either electricity or heat or
both).
• Disadvantage * Take up a lot of space

12. Emerging Technologies in
Wastewater Treatment
Renewable energy technologies, such as wind,
solar, biogas and their hybrids

13. Wastewater treatment plant, which consists of a
preliminary sedimentation tank, a trickling filter,
and a secondary sedimentation tank, can be
powered by renewable energy technologies.
Treatment systems have a simple primary clarifier,
a trickling filter and secondary clarifier, and a
simple denitrification and disinfection system.
Require energy mostly for pumping or ventilation
systems

14. Solar detoxification
Used for the secondary treatment of
wastewater (to remove trace organics and to
kill bacteria and some viruses)

15. • Solar radiation energy (direct sunlight) has been
used for the biological processes in stabilization
ponds.
• Use the UV portion of the solar spectrum to
activate the semiconductor catalyst that produces
hydroxyl radicals.
• Solar energy has long been used for water
purification and disinfection.
• The same principle is used to treat hazardous
wastes in water, air, and soil.

16. Solar catalytic oxidation (SCO)
Solar catalytic oxidation (SCO) involves generation of
highly reactive radicals especially hydroxyl radicals
that degrade a wide range of organic contaminants
present in waste water in presence of a
semiconductor catalyst and UV radiation.
In this oxidation application, the purpose is to
cleanse the industrial waste water for purposes like
irrigation and other domestic uses.

18. Solar Energy to Heat Water
• A flat-plate collector is used to absorb the sun’s
energy to heat the water
• The water circulates throughout the closed system
due to convection currents
• Tanks of hot water are used as storage

20. • Most widely used process for water purification is
Distillation. Solar still distillation is a natural
phenomenon on earth.
• Solar energy heats water in the seas and lakes, and
then evaporation takes place. Water vapor
condenses in the atmosphere and returns to earth
as rainwater.

22. • Heterogeneous photocatalysis the effect of
catalysts and oxidants concentration on the
decomposition degree of the wastewater
• Organic content of a synthetic municipal
wastewater has been successfully carried out by
applying a heterogeneous and a homogeneous
solar photocatalytic method

23. Thank you