THE FILTER PROJECT

Subject Area: Science & Technology
Grade Level: Middle School (6 – 8)
© 2006 by Nathan Balasubramanian

 
Goals

The purpose of this guided inquiry module is to

(a) present water filtration and the associated concepts in an engaging way to middle school students
(b) review the water (hydrologic) cycle and related vocabulary with students
(c) provide students an opportunity to design and build a water filter using only activated carbon, sand, gravel, cotton, plastic cup, wood structural supports, and hot glue
(d) empower students to test their filtered water for

  • conductivity (remove conducting particles so electricity cannot pass),
  • pH (neutralize pH to make it ~ 7 for a basic solution of salt and baking soda in water),
  • turbidity (clean dirty water with tea, vinegar and coffee grounds), and
  • flow rate (captured filter water should have a flow rate greater than 2 ml/s)
 
Objectives

Students should be able to demonstrate their thinking from simple to complex levels in a hands-on guided inquiry project as they design, build and test their water filters and discover the answers to over 35 questions in this revised two-dimensional Bloom's Taxonomy.

Standards Addressed
Students should know and be able to:
  • explain the relationship that ground water has in the water cycle. (Standard 4.3.b in the Colorado Assessment Frameworks-at-a-Glance)
  • demonstrate how technologies can be used to repair damage caused by natural (or man-made) disasters and to break down waste from the use of various products and systems. (Standard 5E in the Standards for Technological Literacy, ITEA, p. 69)
  • understand that fresh water, limited in supply, is essential for life and also for most industrial processes. Rivers, lakes, and groundwater can be depleted or polluted, becoming unavailable or unsuitable for life. (Benchmark 4B/M8 in Benchmarks for Science Literacy, p. 69)
  • identify the sun as the major source of energy for . . . the water cycle (Standard 6D/M17 in National Science Education Standards, p. 161)

Prior Knowledge

Students with a rudimentary understanding of material properties, their interactions with other materials and ability to reuse certain materials will benefit as they design and create fully or partially successful solutions to problems in their STEM classes.

Materials

The following materials are required for students to build and test their filters:

  • activated carbon
  • sand
  • gravel
  • cotton
  • plastic cups
  • wood structural supports
  • hot glue
  • hot glue gun
  • pH paper
  • LASER
  • graduated cylinder
  • stop watch
  • beaker
  • conductivity tester
  • contaminants (coffee, tea, baking soda, salt & vinegar)

Besides, access to a computer lab for accessing the Internet resources created just for this project is essential. Extensive resources have been made available for teachers and students. These are also hyperlinked from a Graphic Organizer generated with Inspiration®.

Lesson Overview

Students should find science, technology, engineering and mathematics (STEM) exciting from their early years of schooling. Clearly secondary school students planning science and engineering careers make their decisions early and are quite persistent (Csikszentmihalyi & Schneider, 2000). This project will give students an opportunity to clean dirty water (coffee, tea, baking soda, salt and vinegar are the contaminants) by designing their own test-filters using only the materials provided. Even as resource constraints challenge students’ creativity, the hands-on nature of the project will actively engage students as they learn about materials and their properties.

Lesson Procedures

Several secondary school students have a tendency to solve problems without adequately understanding or reflecting on the problem on hand. This often results in a dilemma for the instructor because hands-on inquiry learning and problem-solving without domain knowledge merely entertains these students without building their conceptual STEM understanding whereas direct instruction to impart domain knowledge in a sterile learning environment leaves these students unenlightened and unable to see their real-world relevance. To rekindle students’ intentionality and inherent preference for goal-oriented actions, the underlying dynamic instructional model for this guided inquiry module uses a nested framework of STOP → REFLECT → THINK → ACT cycle to foster a creative and thoughtful problem-solving approach in all students.

Introduction

In the first class, students will take their pre-write and pre-tests for the water filtration project. Second, to expose them to the vocabulary essential for successfully designing and building test-filters, students will try to score their best (multiple trials permitted) in an online crossword. After this preliminary exposure to necessary content, students are formally introduced to the problem of water filtration using the PowerPoint presentation

Main activity

Once all students have completed the introductory set of activities, in teams, students will design and build their water filters using only activated carbon, sand, gravel, cotton, plastic cup, wood structural supports, and hot glue. To motivate the students and sustain their excitement throughout the learning process, I have used fake money in all my classes as an incentive to mirror choices and constraints in the real world. This token "microeconomy" in the classroom not only provided students both, individually and collectively, constant and immediate feedback on their performance each class, it also challenged them to become creative problem solvers who were always trying to maximize their limited resources. The recording monetary monitoring link illustrates how the microeconomy functions as an effective classroom management tool. Finally, after building their test-filters, teams will test the performance of other teams’ filters and record the results on four tests – conductivity, turbidity, pH and flow rate. Throughout the designing, building, and testing process, the instructor’s role is to facilitate learning, be the subject-matter expert and seize teachable moments as they guide students through this inquiry learning process.  

Conclusion

Students will demonstrate their understanding of the important STEM concepts embedded in the project in all their assessments, including their conversations, questions, explanations, post-writes and post-tests.

Extension

For those ahead and interested in pursuing the topic further, they will be given additional material (free) to redesign modify and rebuild their filters, after they explain why their designs were fully or partially successful. Some might choose to investigate the brilliant questions brought up by their peers.

Assessment

Assessment is an integral component of this project. As the facilitator and curriculum leader for the project, I used an outcomes-oriented approach that clearly identified desired learning goals and then worked backwards (McTighe & Wiggins, 2005) to develop meaningful learning opportunities to achieve these goals. To identify the success of the project, I have used multiple measures like pre- and post-tests, pre- and post-think writes, students’ self-evaluations and peer evaluations as the Graphic Organizer generated with Inspiration® illustrates. The preliminary findings in my study using archival data demonstrates significant learning gains for all four subgroups of learners in my class.

References

Csikszentmihalyi, M., & Schneider, B. (2000). Becoming adult: How teenagers prepare for the world of work. New York: Basic Books.

McTighe, J., & Wiggins, G. (2005). Understanding by design (2nd ed.). Alexandria, VA: Association for Supervision and Curriculum Development.