soil pollution 1

8/14/2019 Soil Pollution 1

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Soil Arranged in series of zones is called Soil Horizons.

Causes of Soil degradation:

Soil Erosion: The movement of surface litter and topsoil

from one place to another.Due to farming,construction,overgrazing by livestock,

burning of grass cover and deforestation.

Conservation of soil and water by

Area treatment

Drainage line treatment.


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Continuous contour trenches:

Shallow trenches dug across slope and alongcontour lines.

BundsExcess use of fertilizers:N,P,K

Nutrients

Pesticides-DDT

Bio accumulation, Bio-magnification.


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Sustainable Agriculture

Crop rotation

Organic farming

Integrated pest management(IPM)IPM promotes use of biopesticides.

Microbial pesticides-bacteria,fungus,virus,protozoa.

Biochemical pesticide-effects reproductive anddigestive system of the pests.


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Biopesticides

Examples: Bacillus thuringiensis(Bt)

Neem(Azadirachta indica)

trichogramma

Excess Salts And Water logging:

Irrigation water contains dissolved salts likeNacl which remains in topsoil causing

salinization. Due to water logging, salts gets leached

deeper into soil.

Roots get enveloped with saline water-plant


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Municipal wastes, sewage

Pesticides, fertilizersShip accidents

Offshore oil exploration


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Causes:

Control: Sewage treatment plantsScreening:

Its consists of parallel bars spaced 2-7cms

apart followed by a wire mesh with smalleropenings.

Stones,sticks,rags can be removed


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Communiter: breaks the coarsematerials(grinds).

Grit Chamber: light organic settles down.Primary settling tank: suspended solids settle

by gravity.

Chlorinated to destroy bacteria.

Primary treatment removes 35% of the BODand 60% of the suspended solids.

Secondary Treatment:viii.Trickling filters

ix.Activated sludge process

x.Oxidation ponds


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iii. Trickling Filter: It consists of a rotating distribution arm that

sprays liquid waste water-fist size rocks.

slime(bacteria,fungi,algae) which degradeswaste.

slime slides and get collects at the bottomof the filter.


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iii. Oxidation ponds:

- large shallow ponds approximately 1-2m

deep wheresewage is decomposed by

microorganisms.

- accommodate large fluctuations in flow

and lowcost.

Pollution due to oil:

Tanker operations(ballast)Dry clocking

Tanker accidents

Offshore oil production


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Effects of Marine Pollution:

Red tides-phytoplankton blooms of such

intensity that whole area is discolored.Oil slick-removes air present between birds

skin and feather, bird sinks.

Tainting-unpleasant flavor of fish and seafood

due to oil silks.

soil pollution 1

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