Page 160 - SK Year 6 Science DLP
P. 160
Biodegradable or Not?
What will happen to waste materials after they are thrown for a
long time in our environment?
1990 Today
Wow! This toy
Where is my toy car? car is still good.
Teacher, why do wastes from
food and paper no longer exist Oh, it is because these
in the soil? waste materials are
biodegradable.
Biodegradable wastes are waste
Biodegradable?
materials that can be decayed by
microorganisms.
Biodegradable wastes are decayed by microorganisms and are
returned as nutrients to the soil. Biodegradable wastes consist of
organic materials such as food wastes, papers, excretory products,
and faeces.
However, waste materials such as glass, plastic, and
metal cannot be decayed by microorganisms. These
wastes are called non-biodegradable wastes. Toxic
wastes are also non-biodegradable wastes.
glass, plastic, and metal
This means that non-biodegradable
wastes can pollute our environment!
152 9.1.2
