1. Present By Subhrangsu Sekhar Dey AMITY UNIVERSITY
RAJASTHAN
DEGRADATION OF
PESTICIDES AND DETERGENTS
Present By
Subhrangsu Sekhar Dey
M.Sc Applied Chemistry

2. Degradation
Degradation – The breakdown of a substance into simpler molecular or atomic components through chemical reaction(s) either in a plant or animal (metabolic degradation) or in the environment (environmental degradation)

3. Degradation: Process Drivers
Temperature
Relative humidity / Rainfall pH
Insolation
Soil or water biota
Macrophytes
Microbial populations
Worms and microfauna

4. Degradation Half-Life
The time required for half the amount of a substance (such as a herbicide) present in or introduced into a system (living or ecological) to be eliminated, whether by excretion, metabolic degradation, off-site transport, or other natural process

5. Toxicity to Humans and Wildlife
Varies by chemical
Based on the target biochemistry of the product
Much more later in this session

6. Primary Forestry Uses Discussion of silvicultural and other uses
And, of methods of application
Appropriate for the formulation(s) of the pesticide available for use
Much more later

7. Application timing Product specific May also relate to formulation
Gives a measure of selectivity
Discussed for each pesticide and formulation
Summarized in the Label Book in a comparative table for all herbicides

8. Process of Degradation
Lots of differing processes involved

9. Pesticide Movement & Degradation
Runoff *
Leaching *
Degradation
Microbial *
Physical
Hydrolysis *
Photolysis *
Pyrolysis *
Volatilization *
Bypass definitions

10. Pesticide Movement & Degrade
Runoff
movement of pesticide aboveground in water – generally occurs downslope but can also occur on flat or even slightly uphill ground after a flloding rain
Return

11. Pesticide Movement & Degrade
Leaching
Also called percolation – the process whereby pesticide is moved down through the soil profile
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12. Pesticide Movement & Degrade
Microbial Degradation
Breakdown of pesticides by fungi, bacteria and other microscopic organisms
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13. Pesticide Movement & Degrade
Physical Degradation
Hydrolysis -- Breakdown of a pesticide by water
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14. Pesticide Movement & Degrade
Physical Degradation
Photolysis – breakdown of a pesticide by sun or other light
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15. Pesticide Movement & Degrade
Physical Degradation
Pyrolysis – the breakdown of a pesticide by heat or fire
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16. Breakdown generalizations
Hotter temperature = faster breakdown
Higher relative humidity = faster breakdown
More microbes = faster breakdown
pH effect = chemical dependant
More slope = more runoff

17. Degradation of Detergent

18. Biodegradable Detergent
Now days usable detergents are Biodegradable. They convert into different matter after drop of sewage disposal by microorganism. So they are degradable.
Biodegradable Detergent

19. Types Biodegradable
After experiment it was seen that simple chain hydrocarbons
are biodegradable but branch chain hydrocarbons are non -biodegradable
Non -biodegradable

20. Degradation Of Pesticide
Many detergents are resistant to the action of biological agents and thus are not biodegradable. Their elimination from municipal wastewaters by the usual treatments is a problem.
They have a tendency to produce stable foams in rivers that extend over several hundred meters of the river water. This is due to the effects of surfactants used in their preparation. Thus they pose a danger to aquatic life.
They tend to inhibit oxidation of organic substances present in wastewaters because they form a sort of envelope around them.

21. Thank You