# NCERT Solutions for Class 6 Science Chapter 16 Garbage in,Garbage out

## Dealing with garbage

The landfill is an area where all the waste is carried there and dumped(Figure 1). The garbage can be useful or non-useful. The useful garbage needs to be separated from the non-useful garbage. Later, the non-useful garbage is buried under the ground with layers of soil. After, the landfill becomes full then it is constructed into a park and playground.

Figure 1: Landfill

## TYPES OF WASTES

• Waste can be classified into many types. The waste that comes out from the house is called household waste. For example, vegetable peels, stale food, wrapping materials, tins, cans and domestic sewage.
• The waste that comes out from the industries is called industrial waste. For example, chemicals, metal scraps, plastics and waste water.
• The waste that comes out from the agricultural field is called agricultural waste. For example, fertilisers, husks and chaff.

SOLID WASTE
The waste that comes out from anywhere found in the solid-state is called garbage.
Garbage can be further into types:-
The waste that can be decomposed by the microorganisms present inside the soil and air is called biodegradable waste. For example, peels of fruit and vegetables, animal carcass, leaves, papers and manures.
These wastes cannot be decomposed by the decomposers into simpler substances. For example, plastics that can be thrown in the soil cannot be broken down and mixed with the soil for many years. They are harmful to us because of their non-decaying ability. They also create water-logging problems by stuck into the sewage system. Hence, the government takes serious steps to convert these non-biodegradable waste into useful substances

LIQUID WASTE
The liquid waste releases with the three main activities performed by us such as:-
i. Washing clothes near the riverside with detergent and soap flushed dirty water into the river(Figure 3 a).
ii. The washed away water of agricultural fields that contain the harmful pesticides, insecticides and fertilisers into the large water bodies.
iii. The industrial effluents are dumped into the water bodies through pipes(Figure 3 b).

Figure 3: Types of liquid waste: a) Washing and bathing near the riverside; b) Industrial waste dumping into the water bodies.

GASEOUS WASTE
The gaseous waste released in the following ways(Figure 4):-
i. The chimneys of the factories and houses release smoke.
ii. The vehicles exhaust system produce smoke.
iii. Burning of leaves and papers produce smoke.

Figure 4: Gaseous waste.

## WASTE SEGREGATION

This method is used to separate the biodegradable waste to the non-biodegradable waste. We used the following ways to segregate the waste(Figure 5):-
i. Green-coloured bins: The waste like stale food, fruit and vegetables peels, and garden litter collected in the green-coloured bins.
ii. Blue-coloured bins: Recyclable waste like plastic, metal and glass are collected in the blue-coloured bins.
iii. Red-coloured bins: Toxic waste materials like syringes, expired medicines and batteries are collected in the red-coloured bins.

Figure 5: Waste Segregation.

As non-biodegradable waste are not decomposed, the disposal of these waste done differently. Waste management follows the 5Rs strategy(Figure 6).
Refuse
Do not buy unnecessary things whether it’s cheap and easily find.
Reduce
Conversation of things reduces the production of waste. Therefore, using resources in a limited amount is necessary. For example, we should use paper in a limited amount. If a notebook is half used, then we should rip out the unused pages and make a brand new notebook.
Reuse
We should reuse the objects and substances that are no longer in use of their specific purpose. For example, jam bottles and jars are used to store things. We should the water while taking a shower and used that water for flushing and watering the plants.
Recycle
Recycling the substances can enable these substances for performing other works. The need of recycling method is necessary because we cannot reuse all items. For example, old newspapers are recycled to make completely different substances such as paper packets, wrapping gifts and new newsprint.
Reform
Those substances that are not recycled can be reformed by extracting their raw materials to make completely new products. For example, plastic wastes are constructed into brand new products.

## Toxic Wastes

The waste released from harmful substances such as expired medicines, syringes, and batteries is called toxic waste. These wastes are harmful because of their cancer-causing ability. Moreover, these substances carried by the water into the water bodies that are consumed by the animals and plants disturb the food chain cycle.

## Doing Away from Plastic Bags

In ancient times, plastics were widely used all over the planet. On the contrary, the overuse of plastics creates a serious problem because they can emit harmful toxic gases like dioxins while burning, which can increase the risk of causing cancer. Therefore, the maintenance of plastic bags becomes important. We can handle and manage plastic bags in the following ways:-
• We should use reusable bags instead of plastic bags.
• Collect the plastic bags at a specific location where they can be recycled easily.
• Reuse the plastic bags as far as possible many times before disposing of them.
• Use plastic bags only when reusable bags are not available.

## Recycling Papers

Papers are obtained from the trees. Large production of papers increases deforestation. Therefore, recycling papers is an important method to control deforestation. However, the recycled papers are not good as original products. The following steps we can take to control deforestation and make use of recycled papers are:-
• Use old newspapers to cover your notebooks and books.
• Collect the useless paper products and sell them to scrap dealers for recycling.
• Use both sides of the paper while writing.
• Increase the production of brand new notebooks from the unused pages of the notebooks.

There are two methods of managing biodegradable waste: composting and land filling(mentioned in the starting of the chapter) .

### Composting

Breaking down organic materials by decomposers and make them use as fertilisers. The remaining plant parts and the other components of the organic materials are converted into earthy, dark and crumbly substances called compost. They are used to increase the fertility of the soil by providing essentials components.
One of the processes called vermicomposting takes place by adding red worms to the compost pits that degrade the waste into nutrient-rich manure in about 3-4 weeks(Figure 8).

Figure 8: Vermicomposting.

### Practice Question

Question 1 What is $\frac {1}{2} + \frac {3}{4}$ ?
A)$\frac {5}{4}$
B)$\frac {1}{4}$
C)$1$
D)$\frac {4}{5}$
Question 2 Pinhole camera produces an ?
A)An erect and small image
B)an Inverted and small image
C)An inverted and enlarged image
D)None of the above