Albemarle- Pamlico Environmental Education Activity Kit
Objectives:
Materials:
Introduction:
Chlorine is used by most towns and cities to help make drinking water safe. Its use began in 1879 when Englishman Thomas Soper used chlorine to kill typhoid bacteria. It is a very good disinfectant and kills many of the germs that could make us sick. Chlorine is also used by towns and cities to disinfect treated sewage before it is returned to our streams and rivers. Unfortunately, chlorine kills fish just as effectively as it kills germs. If you have ever brought a fish home from the pet store and placed it in fresh water from the tap only to find it mysteriously dead the following day, chlorine was the likely culprit. These fish deaths and those that occur in our rivers and streams are a terrible waste because we can easily remove chlorine from water. Chlorine is similar to many hazardous wastes in that exposure to air or sunlight is very effective in making contaminated water safe. However, many other hazardous wastes are poisonous to people as well as fish.
Why Worry About Chlorine?
Chlorine is poisonous to fish at very low levels. Imagine adding only
one pint of vanilla ice cream to a tanker truck of root beer to make a
root beer. float! No one would be able to see or taste any of the ice cream.
If this same amount of chlorine (1 pint) was added to the tanker (20,000
gallons), the water would be poisonous to fish. Because chlorine is so
deadly to fish and other aquatic animals, it is essential that this form
of hazardous waste be
removed from our treated sewage before it is poured back into our streams
and rivers. Fortunately, water containing chlorine and many other forms
of hazardous waste can be made safe by aerating it (stirring it vigorously)
and exposing itto sunlight. If chlorine isn t removed, chlorine can remain
in our deep, slow flowing, shaded rivers and streams long enough to travel
downstream and kill fish and other animals as it goes.
Activity: Ways To
Make Water Fit For A Fish
Collect a gallon of fresh tap water and place a lid on the container
so the chlorine will not escape. Before you cover the container, smell
the water. If it contains chlorine you will probably be able to smell it
since it smells like a swimming pool. Using your test kit (instructions
should be included with the kit you purchased), test a small sample of
this water for chlorine. If your water is not chlorinated, you can simulate
city water by adding one-eighth teaspoon of household bleach to a gallon
of water. The active ingredient in household bleach is chlorine. Divide
your class into four groups. Each of the student groups should be provided
with several ounces of water, three jars with lids, straws, spoons, and
access to a window sill. Give the students enough water for a chlorine
test. The groups (pretending they are scientists) should devise tests on
how to rid their water of the hazardous waste chlorine. Allow the students
enough time (20-30 minutes) to discuss ideas within their groups and conduct
their experiments. After the experiments, groups should be prepared to
answer the following questions for each technique:
For additional information regarding this Web page, contact Doug Newcomb, in Raleigh, NC, at doug_newcomb@fws.gov
Keywords={same keywords listed above - used for search tools}