Class-6, Science, Chapter:- 16 (Garbage In, Garbage Out) Notes, NCERT Solutions & Frequently Asked Questions

Science

Class:-6, Chapter:- 16

(Garbage In, Garbage Out)

Notes, NCERT Solutions & Frequently Asked Questions

-- Notes --

⭐ Garbage:- Garbage is defined as the items or materials that need to be discarded because they no longer serve any purpose for us or are of no use to us.

• Tonnes of garbage and is generated by us on a daily basis. 

• Garbage is often associated with a pungent smell and a large amount of garbage may release fumes which are not healthy.

• Hence, we put such items in dustbins to be taken to faraway places so that our surroundings are clean and healthy.

⭐ Waste is generated by all of us and has four main sources:-

a) Domestic:- These constitute the kind of wastes that are generated by households, offices schools etc. and include food remains, fruit and vegetable skins, clothing items, used plastic items etc.

b) Industrial:- These constitute the kind of wastes generated by power plants, chemical plants, cement factories, food processing industries, textile industries, each producing waste specific to the kind of industry they are a part of.

c) Agricultural:- This constitutes the kind of waste that is produced by undertaking agricultural activities husks, expired medicines, fertiliser and pesticide containers etc.

d) Commercial:- This constitutes the kind of waste generated by commercial enterprises including disposable plastic cutlery, food items, food packets, textiles etc.

⭐ Landfill:- Not all garbage can be classified as useless as there are some products which can be reused or recycled. 

• When garbage is taken away by the municipality, it is taken to a low lying and open area known as a landfill. 

• Here, garbage is separated into two categories:-

     -- items that can be used again 

     -- items that cannot be used. 

• The items that cannot be used is then spread over the landfill and covered with a blanket of soil. 

• Once it get full, it is converted into a playground or a park.

Image 1.- A landfill

⭐ Useful components of the garbage can usually be classified into two categories:- 

a) Biodegradable wastes:- These are items such as egg shells, vegetable and fruit skin, tea leaves, waste food etc. which can be mixed with soil and rots over time by the action of certain microorganisms. 

• This is usually not accompanied by a pungent smell. 

• Now this mixture of soil and rotten organic materials can be used as manure to provide nutrients to the plants. 

• This process of conversion of biodegradable waste into manure for plants is known as composting.

b) Non-biodegradable wastes:- These comprises of items that do not rot over time by the action of microorganisms. Examples of such items are metal scraps, plastics, glass etc.

⭐ E-Waste:- There is another category of non-biodegradable waste also known as electronic waste or e-waste that is composed of electrical appliances or components that no longer serve their specified function and are hence needed to be reused, re-sold, recycle or disposed off. 

• These are non-biodegradable as no action by any microorganism is effective in breaking them down.

Image 2.- Biodegradable v/s non-biodegradable items

Image 3.- The correct way to dispose biodegradable and non-biodegradable waste

• Garbage should be allowed to be processed by the authorities and not burnt because the burning of garbage releases toxic fumes which are harmful to the health of everybody.

⭐ Vermicomposting:- Vermicomposting is the process of conversion of biodegradable waste into manure with the help of a special type of earthworms called red worms.

• A layer of sand or chicken mesh is used as the base to which all types of biodegradable waste including dried leaves, husk, vegetable peels and remnants of fruit, dried animal excreta newspaper, cardboard etc.

• A little water is sprinkled on this layer. 

• On preparing this mixture, add the red worms to it and covered with a layer of grass or a sheet of cloth.

• Red worms need to be fed. They do not have teeth. They have what is called a gizzard. This helps the worms grind their food.

• Fruit and vegetable remains, tea leaves, grass etc. act as food for the red worms and should be buried 2-3 cm deep in the soil. In a day, a worm can eat up as much food as it weighs.

• Pickles, milk, vinegar and salty materials might help in the growth of disease-causing microorganisms and hence should not be added to the pit.

• They should not be kept in a very hot or a very cold environment. Red worms need care and water.

• They have the potential to double up in a month’s time, given proper nourishment and care.

• The compost gets ready in three to four weeks’ time.

Image 4.- Red worms

Image 5.- Vermicomposting pit

⭐ Recycling of paper:- Recycling paper on a small scale is a relatively easy process.

• All we need to do is tear up the paper in small pieces in a bucket and pour water in it. 

•Let it rest for a day and pound it to make a thick paste out of it. 

•Spread this evenly over a wire mesh to allow the water to drain water. 

•Peel this layered paste and then allow it to dry in the sun. Paper is ready.

⭐ Plastics – boon or curse?:- The plastic problem is mounting day by day. 

•A huge amount of plastic is thrown away carelessly on the street and in water bodies and such irresponsible disposal of plastic can cause a number of problems:-

-- Animals and birds alike, in search of food, end up consuming some amounts of plastic due to which many of them end up choking on these.

-- Although plastic bags seem convenient to store food items, consuming these are very harmful to our health.

-- It gets worse when dirty and thrown away plastic bags are re-used upon mere dusting and washing them which is also very harmful.

-- Upon burning or heating, plastics give rise to toxic and dangerous fumes and gases, which can potentially cause cancer in humans.

-- Careless disposal of plastic on the roads also ends up choking the sewer and drainage systems.

-- The plastic problem is very harmful for all beings alike

Image 6.- The plastic problem is very harmful for all beings alike

• Plastic, while very harmful for the environment has become a very indispensable part of our daily lives and hence it becomes all the more difficult to replace or in some cases, even cut-back on our plastic consumption. 

• Plastics have a lot of characteristic features which give it an edge over its metal counterparts.

• Bioplastics have hence emerged as the most environment-friendly version of plastics which are made of biodegradable items such as corn starch, vegetable fats and oils and other kinds of food waste.

• Bioplastics take about three to six months to be decomposed fully as opposed to several hundred years taken by their synthetic counterparts.

⭐ 3Rs (Reduce, Re-use and Recycle):- Reducing the use of plastic and re-using harmless plastic to help reduce its over-production.

• Recycling paper and such articles whenever possible.

• Carrying jute and cloth bags when carrying out errands to avoid the use of polythene bags.

• Properly disposing plastic and polythene bags. 

• Not using plastic products and bags to store eatables.

• Never burning plastic or dry leaves etc. and disposing them properly.

• Using registers and notebooks made of recycled paper as much as possible.

• Avoid putting waste materials in polythene bags and throwing them on the street.

• Adopting practices like recycling paper and vermicomposting to make the best use of biodegradable waste. 

• This not only helps to reduce the waste that we produce but also becomes a valuable addition to the soil and helps in the nourishment of crops and plants.

• Adopting environment-friendly practices benefits us all

Image 7.- Adopting environment-friendly practices benefits us all

-- NCERT Solutions --

Exercise Questions

Question 1.- 

a) Which kind of garbage is not converted into compost by the red worms?

Solution:- Pieces of cloth, polythene bags, broken glass, aluminium wrappers, nails and broken toys are not converted into compost by the red worms.

b) Have you seen any other organisms besides red worms in the pit? If yes, try to find out their names. Draw pictures of these.

Solution:- Earthworms, small insects like ants and millipedes, are found in pits.

Earthworm

Ants

Millepedes

Question 2.- Discuss:-

a) Is garbage disposal the responsibility only of the government?

Solution:- No, not just the government, but everybody is responsible for garbage disposal. We should bifurcate wet and dry waste, recycle non-biodegradable substances, and we should also reduce the accumulation of garbage in our houses and streets.

b) Is it possible to reduce the problems relating to the disposal of garbage?

Solution:- Yes, it is possible to reduce the problems of garbage by scientific disposal of garbage; we can do it by bifurcation of different waste and also by recycling the waste materials.

Question 3.- 

a) What do you do with the leftover food at home?

Solution:- Leftover food can be collected and used to form compost. Compost produces nutrients necessary for the growth and development of plants.

b) If you and your friends are given the choice of eating on a plastic plate or a banana leaf platter at a party, which one would you prefer and why?

Solution:- We would prefer to eat food on a banana leaf plate because it acts as a harmless substance which helps to form manure by the process of composting, whereas plastic plates cannot be converted into harmless substances by composting. Plastic plates are not degradable, hence can persist in the environment and cause many problems.

Question 4.-

a) Collect pieces of different kinds of paper. Find out which of these can be recycled.

Solution:- Papers such as newspapers, notebooks and magazines can be recycled easily. However, shiny and coated papers cannot be easily recycled.

b) With the help of a lens, look at the pieces of paper you collected for the above question. Do you see any difference in the material of recycled paper and a new sheet of paper?

Solution:- Recycled paper is usually thick or rough when compared to a new sheet of paper.

Question 5.- 

a) Collect different kinds of packaging material. What was the purpose for which each one was used? Discuss in groups.

Solution:- Different kinds of packaging materials used commonly are given below:-

• Cardboard – Shoes, soap, bulbs and other boxes.

• Plastic Bags – Toys covers, sarees bags, shopping bags, etc.

• Wooden Boxes – Fruit baskets and boxes for hardware.

• Jute Bags – School bags, shopping bags, vegetable bags, etc.

b) Give an example in which packaging could have been reduced?

Solution:- By reusing the packaging material, we can reduce the accumulation of garbage.

c) Write a story on how packaging increases the amount of garbage.

Solution:- The basic purpose of packaging is to protect the product from tampering and to maintain its freshness and purity. However, most of the packaging material is used to beautify the boxes and make them look attractive on the shelves. Unfortunately, a large volume of packaging material goes waste and is thrown into the dustbin.

For example, in most places, the dustbins are full of chips and biscuit wrappers.

It unnecessarily increases the amount of garbage. It also increases the cost of the product due to unnecessary packaging. We should seriously consider how to reduce unnecessary packaging.

Question 6.- Do you think it is better to use compost instead of chemical fertilisers? Why?

Solution:- Yes, it is better to use compost instead of chemical fertilisers for the following reasons:-

• It is easy to prepare compost

• Compost is environment friendly as it does not cause any health issues in humans and animals

• Compost will not cause pollution

• Compost increases soil fertility.

• Compost is biodegradable 

-- By Durgesh Pandey

(Eklavya Coaching Institute)