WEEK 9&10

SUBJECT: BASIC SCIENCE

TERM: 1ST TERM

CLASS: PRIMARY 5

TOPIC: WASTE AND WASTE DISPOSAL

Behavioral Objectives: At the end of the lesson, pupils should be able:

1. Identify the components and types of waste.
2. Mention the dangers of poor and improper waste disposal.
3. Explain the advantages of recycling waste.
4. Discuss different ways of disposing of waste

INSTRUCTIONAL MATERIALS:

A chart showing waste product.

REFERENCE MATERIALS

Scheme of work

All relevant materials �� �

9-Years Basic Education Curriculum

Online information

BUILDING BACKGROUND/CONNECTION TO PRIOR KNOWLEDGE:

Pupils are familiar with the topic in their previous classes.

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CONTENT

MEANING OF WASTE

Waste is refuse or garbage. It can be a pollutant or an agent of pollution in our environment. Waste should be disposed of neatly to ensure a healthy environment

Types of Waste

Waste can be a pollutant or an agent of pollution in our environment. Waste is considered in three categories namely: liquid, gaseous and solid.�

Waste generation without proper management strategy can result into environmental degradation which endangers the survival of man and other living organisms. In order to avert this terrible occurrence, people should cultivate the habit of proper waste disposal and make the environment a safer place to live in. This can be done by ensuring that waste generated from our homes, offices, factories, schools, etc is disposed of, lest they become pollutants.

There are two types of waste, namely; refuse and sewage.

a.) Refuse:�

This is the solid form of waste materials such as papers, pieces of wood, broken bottles, metal, waste foods, plastic containers, etc. Some refuse can be decomposed by moulds and bacteria while some cannot. Those that can be decomposed are called biodegradable refuse while those that cannot be decomposed are called non biodegradable refuse.�

Examples of biodegradable waste are: food, meat, paper, etc.�

Examples of non-biodegradable waste are plastic, synthetic resins, rubber; polythene etc.

b.) Sewage:

This is made up of forms of liquid waste. It is a mixture of liquid organic and inorganic materials. These wastes include faeces, urine, mineral salts, waste water, and other liquid forms of domestic and industrial waste. It contains many organisms which are dangerous to our health and safety. These organisms are called parasites or germs. They include bacteria, worms, viruses and protozoa.

Sewage can be turned to fertilizers if treated and well managed. A place where sewage is treated is called 'sewage farm or sewage treatment plant'. Sewage is passed through a large pipe to the sewage treatment plant.

2)� Waste Disposal

Waste disposal is a method of environmental sanitation i.e. the removal of waste (sewage and refuse) from our environment for the purpose of keeping it (the environment) clean and healthy.

Sewage Disposal: The following methods can be applied. The use of: (i) Pit latrine

(ii) Water closet

These two systems should be linked to:

(i) a cesspool or

(ij) a septic tank

Cesspool: This is a covered underground container for the temporary collection of sewage.

Septic tank: This is an underground tank in which sewage is collected and decomposed by bacteria before being drained.

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Pail or Bucket system: This method has been discouraged and is no longer popular because it is considered unsafe for human health.

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Refuse Disposal:

The following methods can be used:

(i) Incineration, (ii) composting, (iii) land filling.

Dustbin: This is first used to collect the refuse before the proper disposal.

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Activity

Mention the methods by which your refuse and sewage are being disposed of in your house.