WATER AND LAND POLLUTION NOTES FREE
WATER POLLUTION:
Water is said to be polluted, when
there are undesirable changes in
the physical, chemical and biological
conditions of water that make it unfit for
human consumption.
Water becomes polluted in many ways:● Stagnant water becomes polluted day by day. It gives out a foul smell and mosquitoes breed there in large numbers causing malaria.
● Pond water get polluted due to human activities like bathing and washing clothes.
Sources of water pollution:
Hot water released into water bodies can also upset the natural cycle. This is called thermal pollution. Hot water can kill aquatic animals and plants that can survive only in low temperature. It also reduces the amount of dissolved oxygen in water. Mostly heated water comes form industries and power plants that use water for their cooling towers.
PURIFICATION OF WATER:
Cleaning of waste water is a process of removing pollutants before it enters a water body. This process of waste water treatment is commonly known as Sewage Treatment.
LAND POLLUTION:
Throwing waste materials like plastic objects, animal waste, dye effluent, trash and garbage causes land pollution.
SOURCES OF LAND POLLUTION:
The use of excessive amounts of fertilizers may decrease the productivity of the soil. Pesticides destroy the insects that harm crops, but pesticides may also destroy other helpful organisms in the soil.
Wind can then easily blow the soil away and rain water can wash it away. Careless farming methods, clearing of land for construction projects such as laying of roads and real estate development also cause pollution.
Pollution patrol:
Take a feather of a bird. Feel it, look at it and examine it with a hand glass or magnifying glass. Sketch what you see. Now dip the feather into water for a couple of minutes. Take it out. Feel it, look at it and examine it with a hand lens. Note down your observations. Then add some cooking oil to the water. Dip the feather again in the oily
Polluting the Planet:
- A seabird that gets covered in oil is obviously in great distress because oil destroys the waxy covering of its feathers and so, the feathers get waterlogged. This often cause the bird to drown or die of cold.
- Pesticides make birds lay eggs with unnaturally thin shells.
- The release of Chloro Fluro Carbon (CFC) from refrigerators has caused the breakdown of the ozone layer. It causes skin cancer.
- Coral reefs are damaged.
