Garbage, Waste Management & Depletion of the Ozone Layer | Science Class 10 PDF Download

How do our activities affect the environment?

There are two major environmental problems:

• Solid waste and their disposal
• Depletion of the ozone layer

Solid waste and their disposal

Solid waste generally comes from homes, farms, industries, and various other sources. It includes:+

• Fruit and vegetable peelings
• Kitchen waste
• Ash
• Paper
• Cow dung
• Human excreta
• Glass
• Plastics
• Leather and rubber items
• Bricks
• Sand
• Worn-out clothes
• Metal objects

When these materials build up, they create a dirty environment and pollute the soil.

The waste we generate can be either biodegradable or non-biodegradable. The way we dispose of this waste is causing significant environmental issues.

Garbage

It’s common to see overflowing dustbins with unpleasant smells in crowded cities. Have you considered that you contribute to this situation? By following proper waste disposal methods at home, we can reduce these unpleasant odours and improve the appearance of waste bins. But what actually happens to the materials we throw away?

Type of solid wastes

• Biodegradable Wastes: These are waste materials that can be broken down into simpler, non-toxic substances by microorganisms. Examples include cattle dung, leftover vegetables, fruits, and compost.
• Non-biodegradable Wastes: These are waste materials that cannot be easily broken down in nature. Examples include aluminium cans, coal, DDT, plastics, and radioactive wastes.

The way we dispose of waste is causing significant environmental issues.

Modes of Waste Disposal

Some prominent methods of waste disposal are :

1. Land fills : In urban areas, majority of the solid wastes are buried in low lying areas to level the uneven surface of land. This method of waste disposal is commonly called land fills.

2. Recycling of wastes : Number of solid wastes (paper, plastics, metal, etc.) can be recycled by sending them to respective recycling units. For instance, paper is sent for recycling into special paper mills ; brock plastic (e.g., plastic bags, buckets, bowls, dishes, mugs, disks, etc.) are sent to plastic processing factories.

3. Preparation of compost : Household waste such as peeling of fruits and vegetables, left-over food, fallen dead leaves of kitchen garden plants and potted plants etc. can be converted into compost and used as manure.

4. Incineration or burning at high temperature : Incineration is the process of burning of substance at high temperature (usually more than 1000°C) and ultimately converting them into ashes. This ash can be diposed of by land fills. In cities, municipal committees / corporations generally do large scale disposal of waste by incineration.

5. Production of biogas and manure : Biodegradable, waste can also be used in biogas plants to generated biogas and manure. Biogas is a cheap source of fuel, and manure, a cheap fertilizer.

Depletion of Ozone layer 

Ozone Gas

Ozone is poisonous in nature.

Ozone is formed in atmosphere by the action of ultraviolet radiation on oxygen gas.

The high energy ultraviolet radiation (UV radiation) coming from the sun splits oxygen gas into free oxygen atoms

O₂ 2O (oxygen atom)

The free oxygen atoms are highly reactive. One oxygen atom reacts with an oxygen molecule to form an ozone molecule.

O₂ + O → O₃ (Ozone molecule)

Ozone Layer

It is a layer of the earth's atmosphere, where ozone is concentrated. The Ozone layer is very important for the existence of life on earth because it absorbs most of the harmful ultraviolet radiation coming from the sun and prevents them from reaching the earth.

The thining of ozone layer is commonly called ozone depletion. Ozone is being depleted by air pollutants. Chlorofluorocarbons (CFCs) are air pollutants that are mainly responsible for the depletion of ozone layer in the stratosphere. Besides, methane (CH₄) and oxides of nitrogen (NO_x) also cause destruction of ozone.

Effect of Ozone Depletion

(i) Ultra violet radiations cause skin cancer.

(ii) These cause damage to eyes and also can cause increased incidence of cataract disease in eyes.

(iii) These cause damage to immune system by lowering the body's resistance to diseases.