I originally created this lab to spice up my mixtures and solutions unit a few years ago. It has evolved into what I HOPE is a thoughtful activity that incorporates mixtures, solutions, density, magnetism, environmental factors, conservation, team building and budgeting skills. I like this lab because it is versatile enough to be used in multiple units. If I don’t have time for it in Physical Science, I use it during Earth Science or even Life Science! This works great for Earth Day projects.
You might also like my Recycled Home Project.
It teeters on the edge of being a STEM activity, but I don’t think it’s quite there. Nonetheless, my students always enjoy it and I am finally making it available for other teachers to utilize. Get it here!
What’s in the Lab?
Reversing Water Pollution.
Grade Level: 3rd-6th | Duration: 45 minutes | Content: Physical Science & Earth Science – Mixtures, Solutions, Properties of Matter, Conservation, Environment and Ecosystems, Earth Day
Materials: Large plastic trays, Filters, Plastic Cups, Plastic Containers, Strainers, Tongs, Tweezers, Magnets, Gloves, Sponges, Foil, Plastic Wrap, Paper Towels
Academic Vocabulary: conservation, pollution, green, environment, mixture, solution,
You will need to create one polluted water sample per group in advance. For my samples, I use sand, dirt, cooking oil, iron shavings, dish soap, a drop of food coloring, and cut small strips of paper, styrofoam and plastic to mix in.
You can use whatever is handy, but I would make sure to at least include the oil, iron shavings, styrofoam and plastic to represent the most common water pollutants. I always add the food coloring to see if anyone realizes they won’t be able to separate it without heat because it creates a solution. Read more about separating food coloring here.
I start the lab with this short YouTube video about plastic pollution, and then open the discussion to talk about other pollutants, the high costs to clean water, and water conservation.
The goal of the lab is to present the cleanest water sample while staying in budget and following the rules. The group with the cleanest sample “wins”. I always try to have some little treat for the winners.
Break the students up into groups of 3-4. Give them 15 minutes to decide on a team name, look over the supply list, choose their items, and come up with a plan to clean the water sample. I allow students to save part of their budget if they find they need additional items later on. No exchanges or refunds (they will ask!). Save yourself some time and get the lab sheets here!
Teams can start as soon as they have presented you their budget and plan. This also gives them an advantage on time if they finish their planning quickly. I usually allow 25 minutes for the water cleaning portion because my classes are 60 minutes, but I have also used as little as 15 minutes. The times can easily be adjusted to fit your schedule.
If students move the water from the “protected” tray area or touch the water with their skin, they are disqualified from winning the prize. Someone ALWAYS touches the water with their hands, and I use this as an opportunity to discuss the dangers of contaminated water.
You students will surprise you with their creativity while completing this activity. I always make sure to show my enthusiasm for the groups that didn’t make the obvious supply choices and got extra creative!
NEXT: Check out Snack Tectonics!