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2. Environmental contaminants,
sources and their remediation.
Zia-Ur-Rahman.
2010-ag-2600

3. Environment:
Word environment is actually derived from the
French word “environner” which means a circle
or around. So;
All the biotic and a-biotic factors around us and
their interactions are environment.

4. Contaminant:
Any type of substance when cross its
specific limits become dangerous for
human and other organisms.
E.g Pb, Hg, As,gasse, petroleum,micro-
organisms etc.

5. Types of contaminants:
Contaminant.
Chemical basis. General basis. Specified basis.

6. 1:Chemical Basis.
There are 2 types of contaminants on the
basis of chemical behaviors;
 Organic contaminants.
 In-organic contaminants.

7. Organic contaminants:
Compounds having (C,H,O) As their necessary
part are called organic compounds and those
organic compouds which cause contamination
are known as organic contaminants.
e.g fuels,solvents,pesticides etc.

8. In-organic contaminants:
Compounds having origin other than organic are
in-organic compounds and contamination
causing compounds related to this group are
called in-organic contaminants.
e.g Heavy metals,nitrates and asbestos etc.

9. 2:General Basis.
There are 2 types of contaminants while
classifying on general basis;
 Point source.
 Non-point source.

10. Point source:
We know about the source of contaminants i.e
from where they are coming.

11. Non-point source:
We do not know about the sources of these
contaminants i.e from where these
contaminants are coming.

12. 3:Specifical Basis.
Contaminants are classified into 2 categories on
the basis of specifical sources as;
 Natural contaminants.
 Anthropogenic contaminants.

13. Natural contaminants:
Contaminants which are not produced from
human activity and are completely natural.
e.g micro-organisms(viruses,bacteria ctc),cd,pb
etc.

14. Anthropogenic contaminants:
Contaminants which are generated and spread
through human activities i.e;
 Industrial activities(Heavy metals)
 Agriculture(Pesticides,pb,As, as toxic agent).

15. REMEDIATION MEASURES.
(Thermal soil remediation plant.)

16. REMEDIATION MEASURES.
There are three types of remediation
measures used;
 Criteria based approach.
 Modified criteria approach.
 Risk based approach.

17. Criteria based approach:
Under this approach,the remediation criteria
selected for a site is adopted as the
remediation measure.
This method is most applicable where site
conditions,receptors,and exposure
pathways are similar with those which are
assumed when developing criteria.

18. Modified criteria approach:
In some conditions,remediation criteria may
be modified within specific limits.
This method applied when land
use,receptors and exposure pathays differ
only slightly from those assumed in the
development of criteria.

19. Risk based approach:
In some circumstances,criteria based
approach is not be suitable for a
site(pathways of exposure,target
chemicals,receptors and other site
characteristics differ from those used to
develop criteria based approaches) and
risk assesment procedure may be
required in the development of site
specific remediation measures.

20. Thank you……!