Unlocking Word
Meanings
Read the following words/expressions found in today’s article.
Read the following words/expressions found in today’s article.
1. extract (v.) [ik-strakt] – to remove or
separate something
Example: Oil is extracted from roses and lavender to be used in making scented
candles.
2. runoff (n.) [ruhn-awf, -of] - water that
comes from land which overflows into bodies of water such as streams, rivers
and lakes.
Example: Runoffs from chemical plants are dangerous.
3. toxic (adj.) [tok-sik] – something
poisonous and deadly
Example: Improper
disposal of toxic wastes cause harm
to humans, animals, and the environment.
4. filter (n.) [fil-ter] – a material used to remove solid substances in
water or gas
Example: The filter in
the coffee maker needs to be replaced.
Article
Read the text below.
Recent studies
show that banana skin can be used to clean river waters. Researchers from
Brazil discovered that banana skin can extract poisonous metals like copper and lead [led] from river water.
These metals
get into river waters through runoffs from farms and factories. They are
absorbed by the soil and threaten the health of humans and animals.
Toxic metals in river waters are normally extracted using
substances like silica, cellulose and aluminum oxide. However, these substances
have dangerous side effects.
Gustavo Castro
from Biosciences Institute in Brazil discovered that banana skins extract more
metal and are much safer to use than the usual substances used.
Castro
conducted two experiments. In the first one, he placed dried and powdered
banana skin into a container of water with toxic metal. In the second
experiment, he used a filter made out of banana skin. Both
experiments showed that bigger amounts of metals get stuck to the banana skin
compared to the usual extracting substances.
Other plants
like apple, sugar cane, coconut and peanut have also been proven to extract
metals from water.
Castro warned
people not to use banana skin to filter water in their homes. The metal content
in tap water is very small that the average person
may not know if the banana actually extracted the metal.
Banana skins
are better used in cleaning wastes from factories.
Viewpoint Discussion
Enjoy a discussion with your tutor.
Discussion A
·
What
kinds of factory are common in Japan?
·
What
do you think should the government do to prevent these factories from emitting
harmful wastes to our rivers or lands?
Discussion B
·
What
science inventions do you think are harmful to the environment?
·
As
an ordinary person, what can you do to protect our environment?
