Page 175 - Science Class 06

Rubbish : Paper, plas cs, rubber, wood, glass, When biodegradable wastes are dumped on
metallic wastes, polythene bags, cardboard, land, micro-organisms like bacteria and

etc. are called rubbish. These wastes are fungi start their work and break them into
generated from homes, industries, offices, simpler substances in nature which are
schools, etc. consumed by plants or other organisms. All
the plant and animal products such as food
Liquid Wastes : Liquid wastes include wastes
materials, wood, clothes, paper, leather, etc.
discharged from kitchen and bathrooms
are biodegradable wastes.
which contain soap, oil, detergent, human

excreta. Besides, a large amount of liquid
wastes or effluents is also discharged from
industries which contain chemicals, metal
wastes, etc.

Biodegradable Wastes

Non-Biodegradable Wastes

Wastes which cannot be decomposed into
simpler substances by natural agents like
bacteria or fungi are called non-biode-
gradable wastes.

Effluents discharged by the industry. Non-biodegradable wastes accumulate in
the environment and cause soil, air and
Gaseous Wastes : Harmful gases, smoke, water pollu on. Many pes cides, lead,
and metal par culate come in this category.
mercury, metal oxides and synthe c
These wastes are produced by motor
polybags are the examples of non-
vehicles, industries and thermal power
biodegradable wastes. Our government has
plants.
started a drive to convince people not to
CLASSIFICATION OF WASTES use polybags.
Wastes can be classified on the basis of
their nature into two groups:

v Biodegradable Wastes

v Non-biodegradable Wastes

Biodegradable Wastes
Wastes which can be decomposed into the

raw materials by micro-organisms are called
biodegradable wastes. Non-biodegradable Wastes

Science-6 175