Sewage water is consumed by people, but they do not get sick.
Compare multiple design solutions and their merit for separating substances from a mixture.
Water collected from a town may be contaminated. The town officials are requesting help to design a process that will identify the particles in the water and then clean the water.
Click here for NGSS, CCSS–ELA, and California ELD standards.
In the last lesson, students investigated filtration and evaporation as two processes that could clean the town water samples. Students began to use an engineering design process which included defining criteria and constraints.
This lesson focuses on students using all the information they have gathered regarding the properties of matter to build a process or system to identify and separate the materials in a town water sample.
Students will also evaluate their processes for success in meeting the criteria and constraints and compare their results to the results of other teams’ processes. By the end of this lesson, students will be closer to understanding the anchoring phenomenon that sewage water can be processed so that it is drinkable.
The intent of this lesson is to allow students to determine their own design for separating the mixture. Their plan should include these components:
Discussions should include:
30 minutes | Engage | |
60 minutes | Explore Plus overnight–or longer–for evaporation | |
60 minutes | Explain 1 | |
45 minutes | Explain 2 | |
45 minutes | Elaborate | |
35 minutes | Evaluate |
Define a simple design problem to identify and separate materials based on their properties.
Sand | Salt | Iron |
---|---|---|
Does not dissolve in water Grainy, gritty Not magnetic |
Dissolves in water Grainy Not magnetic |
Does not dissolve in water Grainy Magnetic |
Facilitate student discussion and push students to “Ask questions to clarify and/or refine a model, an explanation, or an engineering problem.”
Apply scientific ideas to solve design problems and to gather data on substances based on their unique properties.
Facilitate the student planning and discussion by asking specific questions about the materials they are using, what might happen if a different material was used, and why they think the material they have chosen is the best for a specific purpose. Provide these sentence frames:
We will use _____. It is the best choice because _____. If we use _____ instead, then _____.
This will facilitate the discussion with another set of partners when they share their plans.
The student design should include evaporation of the remaining liquid. Allow time for the liquid to stay out at least overnight and preferably over the weekend.
Generate and compare multiple solutions to a problem using the properties of matter to clean a water system.
Efficiency means how well the substances were separated. Efficiency can be evaluated by determining which team recovered the most of each substance separated with the least amount of impurities.
Reflecting on Lesson 4: Cleaning Water, efficiency should include the idea that the separated weight and volume for each type of matter removed is the same as the starting weight and volume of the Town Water Sample.
Generate and compare multiple solutions to a problem using the properties of matter to clean a water system.
Compare solutions used to separate substances based on their unique properties.
Make a claim about the merit of a solution and communicate solutions to clean and identify matter in contaminated water.
Use the posters to assess students’ understanding of water filtration.