Blend mechanical engineering and life science in this engaging activity. Discuss and consider optimal water filtration systems to ensure happy and healthy marine life.
Part 1 with Ms. Flowers
Learn how an after school paper airplane competition inspired Dakotah to pursue a STEAM career.
Part 1 with Ms. Flowers
Discover how Dakotah uses engineering to ensure the safety and well being of marine life.
Water Filtration 5E
Engage
Select an animal and view the live cameras available through one of the local California aquariums:
Ask: What do these animals need to survive?
List student questions on the board.
As an extension, create a T Chart and label the sides SIMILAR and DIFFERENT. Ask students to compare their needs with the needs of marine life.
Lead students towards a discussion on maintaining a healthy marine environment. This discussion might include:
ways to reduce pollution in the water.
ways to remove wastewater from the tanks.
Explore
Using the prior discussion in the Engage step as a foundation, instruct students to research an animal found on one of the animal cameras. Ask students to learn about:
Animal diet
Amount of food needed per day
Type of environment (fresh or salt water)
Conditions of the natural habitat
Students should consider how much waste water their filter will process each day.
Students can accomplish this by calculating the amount of food consumed per day multiplied by the number of animals in each tank.
Alternatively, students can research how many gallons are in the tank of their chosen animal, and how many gallons per hour are typically filtered. Ask students to calculate how long it takes to filter an entire tank.
Tank Size (G) Ă· (G) Filtered per Hour = Time it takes to filter the tank once.
Assessment:
Younger students (K-3) should understand that a bigger tank likely requires a bigger filter.
Older students (4-8) should perform more precise calculations on waste water based on the information they researched.
Students sketch a drawing of their filter design first. Second, students build their own water filtration system for the animal chosen above using a pre-cut bottle, a coffee filter and provided filter materials (See Materials list to the right).
Note: For younger grades (K-2), guide students through the process of building the water filter as a whole class.
Once the filter is constructed, students pour a small amount of dirty water through their water filter at the top of the plastic bottle. The filtered water will collect in the bottom of the plastic bottle.
Students will compare their filtered water with a control, which is a clear jar filled with pre-filtered water.
Explain
Students develop an expanded drawing (model) of their water filter.
For younger grades (K-2), draw a tall rectangular box that has one row per material used. Students are to draw each material used, one per row.
For older grades (3-8), provide students with a sheet that contains a rectangular box and instruct them to draw their water filter. Students should add a label at each layer.
Students use their model to describe how the dirty water enters the top and becomes clearer as it exists the bottom.
For older grades (5-8), ask students to analyze the water clarity from each filter. Based on the differences in clarity, students construct an explanation for the best water filter design. The best water filter design takes into account the materials used and the order of each material in the filter.
Elaborate
Create a second T Chart and ask students to identify similarities and differences between the water filter they created versus water filtration used for drinking water.
Videos that demonstrate water treatment and water filtration include:
Alternatively, deconstructing an off the shelf water filter could be used in place of the videos above. Note: Care should be taken when opening water filters, and the activity should be guided by an adult.
Evaluate
Students market their water filter product for use with the observed animal in the Engage step. Students can write a letter, draw an advertisement, or create a recorded commercial to be sent to the aquarium where they observed their animal. Students explain:
Why filtering water is important for the marine animal observed.
How their water filter is designed.
Why their water filter is the best design.
Meet Dakotah Flowers
Aquariums and zoos provide the public with unique opportunities to engage with marine life up close. Dakotah Flowers, a mechanical engineer, designs the systems necessary to ensure the health and safety of the marine life on display.
Designing water filtration systems often starts with conversations about animal waste. Dakotah needs to know the quantity of waste water produced by the animals to ensure the system designed is sufficient to maintain safe water in the tank.
There are many classic classroom engineering activities that include building bridges and towers. The best engineering activities go one step further and considering the people or things that will use the design. Dakotah relies on her life science knowledge extensively because she needs to design water filtration systems around the unique needs of marine mammals and sea creatures contained in the tank.
In this activity, students design a device that filters dirty water. Students are encouraged to go beyond the design and consider the people and animals who rely on engineers for clean and safe water.
Water Filtration Activity
Students will engage in the engineering design process to design and build a water filtration device using recycled materials and off the shelf supplies.
Materials
Recycled plastic water or soda bottles, one per group.
Clear plastic cup, one per group.
Round coffee filter, one per group (or a paper towel or old shirt).
Scissors or a utility knife.
Dirty water in a large jug, mix any combination of the following: dirt, coffee grinds, small sticks and leaves, sand, sprinkles, glitter, or other fine particles.
A clear jar with dirty water that will serve as the pre-filtered (control) water.
Prepare
Cut each plastic bottle across the middle and recycle the bottle cap. Turn the top of the bottle upside down and place it inside the bottom of the bottle. Place the coffee filter in the open end of the bottle. Instruct students to place their water filter material inside the coffee filter.
The Engineering Design Process
Educators can use several versions of the Engineering Design Process (EDP). The version below, from NASA's education page, uses six succinct words to describe the six steps in the EDP.
Students begin at the ASK step when they consider "what is the problem I want to solve?"
The PLAN step is crucial. Students can plan with a drawing or a bullet list of steps. Students should have their plan approved by the educator before being given access to the building material.
In the IMPROVE step, students receive feedback from their peers, their teacher and through data gathered during the experiment.
Emphasize that the EDP is non-linear and that students are not "finished" once they complete their first design. There is always room for improvement!
Credit: NASA STEM Engagement