is the layer of organic and inorganic
material that forms the top surface of
earth’s crust. The organic material is
derived from decayed remains of plants
and animals. The inorganic material is
made up of rock fragments.
is the introduction of contaminants or
substances which result in a change of
soil quality. Soil pollutants adversely
affect the physical, chemical and
biological properties of soil and reduce
Causes/Sources of soil pollution:
Excessive use of pesticides, fertilizers
increases toxicity of soil.
Discharge and dumping of industrial
effluents on land.
Accumulation of solid waste i.e. garbage
and refuse etc and radioactive
substances from nuclear plants.
Soil erosion causes loss of top layer of
soil and reduces soils holding capacity
and makes it less fertile.
Open defecation of animals and human
Control of soil pollution:
It is a technique for treating polluted
soil. It utilizes micro-organisms like
yeast, fungi, and bacteria to breakdown
or degrade hazardous substances into
less toxic or non toxic substances like
water or CO2.
Factors that affect Bioremediation
Temperature favorable for organisms.
Availability of nutrients (like N, P, K)
Availability of H2O.
Availability of Oxygen
It is a four step process which is as
Biostimulation: Stimulation of
biological activity in the various soil
Bioventing: Injection of air in the
layers of soil
Biosparging: Injection of nutrients in
the various layers of soil