Class Notes NCERT Solutions for CBSE Students
Question: What is the difference between biodegradable and non – biodegradable waste?
Answer:
biodegradable
non -biodegradable
1. The biodegradable waste materials rot easily and mix with the soil.
Non -biodegradable waste materials do not rot easily. They do not mix with the soil and remain in the environment for a long time.
Micro – organisms, such as bacteria, fungi and earthworms help to compose such waste.
They may take thousands of years to decompose. Unit then, they choke drains, clog the land and water bodies and pollute our surroundings.
Leftover food, fruit and vegetable peels, paper and leaves are all biodegradable.
Plastic goods, synthetics, aluminium cans and silver foil are a few non – biodegradable waste materials.
Question: Write the four methods of waste disposal discussed in the lesson.
Answer: Methods to disposal waste:
- Burning: Waste is first collected at on place and then burnt. Chemicals and other poisonous waste is burnt in a large furnace. This is harmful and causes air pollution.
- Open dumping: Waste is loaded in trucks. It is then taken far away from the town or city and dumped in the open. Disposing of waste in this way pollutes the environment.
- Landfills: Landfills are found in the outskirts of the city. Deep ditches are dug in the ground and the garbage is dumped in them. When full, these ditches are covered with soil. In some places. parks and gardens are built over them by the government.
- Compost pits: In villages, people dig a pit in the ground and dump their household waste in it. After some time, this waste turns into manure. It is also called compost. This manure is used by farmers in their fields. Crops grown using natural manure instead of chemical fertilizers are healthier. They are called organic foods.
Question: What is recycling? Discuss its benefits.
Answer: Recycling is the process of reusing a product or producing a new product from a used or waste material. For eg.- Used paper is a recyclable waste. Old paper can be used to make new paper. Kabariwalas buy old news papers and magazines from us. they then sell it to factories which make fresh paper from the old. Some plastic wast and glass bottles can also be recycled in the same way. Dirty water can be recycled by using it for watering the plants.
