Sponsored By
Ambassador
STEM Kits
“Dirty Water
Project”
“Justice”
These activities were developed exclusively
by Girl Scouts - Western Oklahoma and
correlate with the themes and practices
found within the “Justice” Girl Guide book.
The STEM Kit in A Box contains the necessary
supplies to complete each activity, except
where noted. You will use the material in
these kits to help the girls earn their Journey
badges as Ambassadors. These activities
MUST be completed as part of their Journey
throughout the course of the year Each kit
includes a leader guide that gives background
information on the activities. It is recommended that the girls guide themselves
through these activities with minimal guidance from you, the leader.
Chris Simon, STEM Coordinator
Girl Scouts – Western Oklahoma
[email protected]
Phone: 405-528-4475 or 1-800-698-0022
This kit is provided through an award from the Oklahoma NSF EPSCoR program
and is based on work supported by the National Science Foundation under Grant No. IIA-1301789.
Project title: “Adapting Socio-ecological Systems to Increased Climate Variability.”
Any opinions, findings & conclusions or recommendations expressed in this material are those of the author(s)
and do not necessarily reflect the views of the National Science Foundation. www.okepscor.org
Sponsored By
OK NSF EPSCoR Content Reviewers: Dr. Jody L. Campiche, Assistant Professor of Agricultural Economics and
Extension Economist, Oklahoma State University; Dr. Renee McPherson, Associate Professor of Geography and
Environmental Sustainability and Girl Scout, University of Oklahoma
Ambassador
STEM Kits
“Dirty Water
Project”
“Justice”
Civil, chemical, and environmental engineers work together to develop new water treatment systems or to
improve existing ones. In this activity, Ambassadors will investigate different methods of aeration and filtration
for removing pollutants from water and will then design and build their own water filters.
Materials:
Each group of 3 girls should have:
• 1- 2 liter plastic bottle, cut in half horizontally
• 1- 3 inch square of mesh (fine nylon screen, fine cheesecloth,
etc.)
The groups should share the following:
• Filter materials:
° Filter paper or large coffee filter (at least 6 in
diameter)
° 6 cotton balls
° roughly 6 cups soil
° roughly 6 cups sand
° 1 dozen large and small pebbles (total)
° roughly 6 cups activated charcoal (used for potting
plants and in aquariums)
° 1 aquarium aerator or a mechanical stirrer/mixer
(aeration pumps for fish tanks work well)
• Measuring cups
• 2 large jugs or jars (approximately 1 gallon in size, plastic gallon
milk jugs with lids are great) for mixing/storing “polluted water”
(recipe to follow)
• 1 rubber band
• 1 spoon or other stirring utensil (chopsticks work well)
• “Polluted water” made by mixing the following, in amounts at
your discretion:*
° Water (enough to fill the jugs/jars approximately ¾
full) + green food coloring + dirt + organic matter
(grass clippings, orange rinds, etc.) + dishwashing
detergent + vinegar + baking soda + salt + pepper +
pieces of polystyrene foam (foam peanuts) + small
pieces of newspaper + other ‘pollutants’ you wish to
include
*You will need to prepare the “polluted” water sample and let it
ripen in a sunny spot for a day or two.
Introduction
Water is often considered the “universal solvent” because it
can dissolve organic (natural) or synthetic (manmade)
substances into a solution. Some of these products break
down easily in water; others break down very slowly or never
do. Water naturally becomes purified when it filters through
soil or evaporates into the atmosphere.
Many societies used to dispose of waste and garbage directly
into lakes, streams, and oceans. Now, developed countries
require polluted water to be treated. Environmental,
chemical, and civil engineers work to improve existing water
treatment systems and design new ones to ensure a steady
supply of safe, clean water both now and in the future.
Generally, there are three ways to treat raw sewage or waste
water. First, the liquid is allowed to settle and then is exposed
to oxygen by stirring or bubbling air through it (aeration). This
allows many harmful organic pollutants to react with the
oxygen and change into carbon dioxide and water. Second,
the liquid can be filtered to remove the particulate matter. It is
important to note these procedures don’t result in pure
water, but at least help take major contaminants out of the
water. Lastly, the solution is treated chemically (with chlorine
or ozone) to kill many additional harmful things like bacteria.
Before the troop meeting, a leader or troop member will have
to prepare the polluted water and place the aerator/mixer in
one sample of “polluted” water. Let it sit overnight before
Parts 1 and 2 of the activity (depending on how many groups
choose to use aerated water for their best filter).
Be sure to mix the solution thoroughly before preparing the
samples.
Ambassador
STEM Kits
“Dirty Water
Project”
Procedure
Part 1 –
Divide the girls into groups of 3. The girls should be
encouraged to take pictures and post their progress at
the Girl Scouts - Western Oklahoma STEM Blog at
http://kidblog.org/GSWESTOKSTEM/
Your Challenge
SAY: Today, you are engineers working for the Girl
Scouts - Western Oklahoma Environmental Engineering
Company. The company has been asked to design a
new water filtration system for a small community with
a polluted water supply. We are going to focus on the
second step in the water treatment process--filtering.
First, we are going to look at different types of filter
material to determine which ones work well. Then each
group in the company will design a filtering system to
clean the polluted water. The best filtering system will
be used in the small community.
Give each group the following
supplies:
• a precut 2-liter bottle
• a ½ to ¾ cup (100-200 mL) sample of the effluent
or polluted water in a cup
• Only one type of “filter” (one group will not get a
filter as they will test the mesh only)
• a spoon
“Justice”
1. Each group will make an assessment of the
“polluted water” and describe in words what it looks
and smells like. (REMINDER--It should go without
saying, but remember--you should never, ever taste
the solution.) Record your thoughts and take
pictures to place on the
http://kidblog.org/GSWESTOKSTEM/
2. Now, gently stir the effluent and record
observations of that as well. Record these
observations on the blog.
3. Ambassadors will need to write down a prediction
for what they think each particular filter material will
do.
4. To test the filter materials, Ambassadors will
place them, one at a time, into the inverted 2-liter
bottle top, as in Figure 1. (Note: The filter should be
placed in the end of the bottle with the neck; it will
function like a funnel. Use the other half of the
bottle as a stand.) You should take a picture of the
set up and place it on the blog site.
5. Ask students to gently stir the polluted water and
then slowly pour it into the filter. (Note: When using
the filter paper, be careful not to pour liquid above
the top of the filter.)
6. Now, observe what happens during the filtration.
Some filtrations will take longer than others. Record
your observations and take a picture of the filtered
water. Record that on the blog as well.
7. After the troop has collected their data, the
results should be shared on the blog page.
Ambassadors should record everyone’s results in
their group data section on their worksheet as well.
Ambassador
STEM Kits
“Justice”
“Dirty Water
Project”
8. Now, as a troop, look at the aerated sample. Discuss what aeration is and how it
works.
(Aeration is the process of adding air to water. It is often done as part of the water
purification process. It allows many harmful organic pollutants to react with the
oxygen and change into carbon dioxide and water. The basic purpose of aeration is
the improvement of the physical and chemical characteristics of water for public
supply. Primarily, this improvement involves the reduction of objectionable tastes
and odors, but some additional benefits of aeration as a preliminary step to other
purification processes have also been noted. Aeration of water improves the taste
by supplying oxygen, rescuing free carbon dioxide and eliminating much of the
hydrogen sulfide and other odorous constituents present.)
9. Now the girls will work in their engineering design groups to design the best water
filtration system given the filter choices and a choice of aerated or non-aerated
water. (They can use as many of the filtering items as they want.) They are asked to
record and explain the choices for their filter and continue to post any and all
observations to the blog.
10. Do the girls think that the order of the layers matters? Why or why not?
•
•
Collect all supplies and dispose of used items properly.
Rinse the 2-liter bottles in preparation for Part 2
Part 2 –
1.
Have the girls break into their groups assigned during Part 1.
Give each
group:
• A prepared 2-liter bottle,
• ½ to ¾ cup (100-200
mL) of the “polluted
water” in a cup (aerated or
non-aerated, whichever
they chose)
• A spoon
• pH paper for testing the
water before and after
filtration (The girls will use
the pH paper and a pH
guide to help them
determine the pH of the
solution during different
stages of the process
(plain water, “polluted
water” before treatment,
after aeration, after
filtering with one filter, and
after using their final
filter.)
Ambassador
STEM Kits
“Dirty Water
Project”
“Justice”
2. Distribute the filter materials as needed. (Note: Assign a
specific “materials” person from each group to collect the
supplies from a central location in the room.)
3. The Ambassadors will now need to build their groups’
water filter system and take a picture of it and place it on the
STEM Blog located at: http://kidblog.org/GSWESTOKSTEM/.
4. When the filter is complete, the girls should gently stir the
polluted water and then slowly pour it into the filter. (If filter
paper has been used, girls will need to be careful not to pour
liquid above the top of the filter.)
5. They should observe what happens during the filtration
process. (Note: Some filtrations will take longer than others;
the girls should not panic if their filtration takes longer than
another groups’.) Groups should record their observations;
take pictures of the filtered water and record it on their data
collection worksheet and/or the GSWESTOK STEM blog
page.
6. As their filters finish cleaning the water, the girls will record
their results and complete the discussion questions on the
data collection worksheet. Have them compare answers
with a group member.
7. After all the groups are finished, label and line up the
samples. Ask each group to present their filter system to the
troop (aka Girl Scouts - Western Oklahoma Environmental
Engineering Company) and discuss the choices they made
and why.
8. Have the troop vote and have a discussion about which
water is the cleanest and why.
Safety Issues
Remember that when they are making
observations, girls should only use sight and
smell; they should never taste the solution, even
if it looks “clean.”
Troubleshooting Tips
• Be sure to have paper towels/rags on hand
in-case spills occur.
• Consider any of the girls’ allergies before
creating the dirty water sample.
• It helps to pre-wet the filter paper so that it
sticks to the sides of the “funnel.” You may want
to have an eyedropper and some tap water
available for this purpose.
• Remember to dispose of the waste from this
experiment properly! Most times the “polluted”
water can just be washed down the drain;
however, if you have used any chemicals, you
will need to dispose of it according to proper
disposal methods.
Ambassador
STEM Kits
“Dirty Water
Project”
“Justice”
Data Recording
After all the groups have collected their data, share the results as a troop on the blog page. You’re
encouraged to include any combination of photos, video, audio, and text.
Have the girls complete the discussion questions and post these to the blog as well.
Discussion questions for the girls to answer on the blog:
Did your filter work as you expected it to? Explain why or why not.
Do you think the filtered water is clean enough to drink? Explain why or why not.
Do you think the filtered water is clean enough to put into a river? Explain why or why not.
List some ideas for ways you might get the “polluted water” cleaner?