A Middle School STEM Challenge

Overview

Located south of the Assiniboine on the western edge of the city of Winnipeg, River West Park Middle school is part of the Pembina Trails School Division and serves students in kindergarten through to grade 9. River West Park’s program aims to challenge children academically, guided by Manitoba’s provincial curriculum standards. Todd Johnson is a science teacher at River West Park Middle School, and is integrating a STEM component into his grade 8 science class through a water quality engineering design challenge.

Investigation

“My students are conducting water quality project right now where they have been tasked to design a water filter. We will then compare which group’s filter does the best job at filtering out the water” explains Todd. “Before we started the project we had an in depth water quality discussion. I then took some time to show the students how the PASCO water quality sensor works. We tried a few different water samples as a class to view how the sensor reacted to different water samples. I then used the free water quality lab in SPARKvue (projected using a tablet and ScreenBeam) to discuss the specifics of how this particular water quality sensor works (i.e.: using electrical current etc..). Students proceeded on their STEM project, by planning and designing water filters from a given set of supplies. They could choose to use whatever they wanted. Supplies included cotton balls, coffee filters, paper cups, bowls, jay cloths, clothes-pins and paper, among other items. Water samples were obtained from a local pond, and made worse by adding salt and sand. We obtained a base reading for the water sample (~8350), and then each group tested their water filter to see whose filters did the best job of creating a cleaner water sample.”

Outcome

“The results were interesting, since samples after filter use were only marginally better than the original reading.” Todd and his students used these results to brainstorm on the likely reason for such outcomes. “The students discovered that salt is not filtered in this process and that it must be the salt which accounts for most of the poor water quality reading.” “Some samples actually made the reading increase. Students were again challenged to determine the possible reasons for such an outcome. They realized that some groups had used sand in their filters, and that the sand may have added other contaminants to the water.” “I would like to expand the project with further explorations,” says Todd. “Students could investigate ways to remove salt from water and could try those methods to see how that changes the reading on the sensor.” A ‘hands-on’ STEM challenge! River West Park Middle School, 30 Stack Street Winnipeg, MB

PASCO Products

• Sparkvue Software PS-2400
• Water Quality Sensor PS-2230