Waste Disposal: Computers and the Environment (Developed by SEPUP)
module #WD-2
Management of the waste produced throughout the life cycle of electronic products is extremely complex and challenging. In this module, students learn about the toxic and non-toxic waste issues associated with the manufacturing and disposal of computers. In a series of activities, students simulate the production of circuit boards and the disposal of the resulting liquid toxic waste. Students then investigate a variety of options for handling obsolete computer waste and learn about integrated waste management.
Finally, they use their understanding of the waste issues and disposal options to recommend a computer company to purchase computers from. The module provides many opportunities for students to develop their skills in using evidence and weighing trade-offs to make decisions.
THIS MODULE INCLUDES A TEACHER'S GUIDE THIS MODULE REQUIRES 16 SEPUP TRAYS THAT ARE NOT INCLUDED
This module has 8 activities which will require 12 to 15 ~50-minute class periods to complete.
1. Producing Toxic Waste
Students discuss the many materials used to make electronic products, such as computers. They etch circuit boards to simulate the production of one component of a computer. Students then explore the waste produced in manufacturing circuit boards and begin to consider the issue of toxic wastes produced during manufacturing.
2. Dilution of Copper Chloride
Students explore dilution as a disposal method for solutions that contain metals. They perform a serial dilution of 100,000 ppm copper chloride to develop an understanding of the concept of parts per million (ppm) as a way of expressing the concentration of a solution. They then test a copper chloride solution with ammonia to demonstrate how chemical tests can reveal concentrations lower than those visible to the human eye. The tests are used to determine the concentration of the used copper chloride from Activity I.
3. Reclaiming Waste Through Metal Replacement
Students learn that wastes from many industrial processes contain valuable substances that can sometimes be economically reclaimed, recycled, or sold as by-products. They investigate metal replacement reactions and compare the effectiveness of three different metals in extracting copper from the used copper chloride solution produced in Activity I. After determining which of the metals removes copper ions from the solution, they examine cost and safety information to decide which metal would be the best to use.
4. Another Approach to Reclaiming Metal
Students learn that the most common industrial method for reclaiming dissolved metals is through precipitation reactions. They use chemical solutions to precipitate copper compounds from used copper chloride. They filter the resulting mixtures and use the color of the filtrate, as well as the ammonia test, to determine the effectiveness of the reactions in removing copper. (The filtrate is the liquid that filtered through the paper.) Students compare the advantages and disadvantages of using metals and chemical solutions to precipitate copper. They then evaluate the different approaches of handling toxic waste.
5. Investigating Sanitary Landfills
Students learn that toxic waste is produced not only during manufacturing processes but also when products are discarded. They explore the use of landfills for the disposal of computers. Students then design the base layers of a landfill and compare leachate flows to that of a simulated dump.
6. Incinerating Toxic Waste
Students learn that incineration reduces the mass and volume of solid toxic wastes and maybe used as a source of energy. Simulated metal waste is burned, and the resulting smoke and ash are tested for the presence of metals. Students evaluate the use of incineration as method for handling toxic wastes.
7. Recycling, Reuse, and Source Reduction
Students examine and discuss recycling, reuse, and source reduction as options for handling obsolete computers. They use evidence to rank the options they have studied throughout the module for handling computer waste. They also begin to examine what they can do as consumers to affect the amount of computer waste that is produced.
8. Purchasing Computers
Students use what they have learned about toxic waste and the lifecycle of computers to reflect on how they can influence the production and disposal of toxic waste when they purchase products. They are asked to take the role of a middle school principal with a fixed budget who has to choose a computer company as a supplier. Students perform a trade-offs analysis and use evidence from the previous activities to support a decision.
- Manufacturing and disposing of products produces waste. Some of this waste is toxic. Toxic waste is harmful to living organisms and must be disposed of according to strict guidelines.
- One way to reduce the amount of toxic waste is to reclaim toxic elements through metal replacement reactions or precipitation reactions.
- One way to reduce the amount of toxic waste is to extend the useful life of products through reuse and recycling.
- Gathering relevant evidence is essential for thoughtful inquiry and good decision making.
- Making decisions about complex issues often involves trade-offs and evaluating issues requires an analysis of both risks (costs) and benefits.
Content List in Waste Disposal: Computers and the Environment (Developed by SEPUP) is as follows:
| Quantity | Description |
|---|---|
| 1 | Teacher’s Guide with reproducible masters for Student Sheets |
| 1 | Videotape, Hazardous Materials/Waste Disposal |
| 160 | Filter paper circles, 7cm |
| 80 | Aluminum washers |
| 80 | Iron washers |
| 80 | Zinc washers |
| 80 | Copper coated circuit boards |
| 16 | SEPUP Filter Funnel |
| 16 | Stir sticks |
| 16 | Droppers |
| 16 | Steel wool pieces |
| 16 | 30 ml graduated cups |
| 16 | Plastic spoons |
| 10 | LAB-AIDS® Etching Trays |
| 10 | 9 oz plastic cups |
| 9 | LAB-AIDS® Leachate tubes (1.25" dia, 5"H) |
| 8 | Permanent markiers |
| 8 | Drop control bottles of "Water", empty |
| 8 | Drop control bottles of Ammonia solution, 5% |
| 8 | Drop control bottles of "Used Copper Chloride", empty |
| 8 | Drop control bottles of Sodium Carbonate solution, 0.8M |
| 8 | Drop control bottles of Sodium Phosphate solution, monobasic, 0.8M |
| 8 | Drop control bottles of Copper Chloride solution, 100,000 ppm |
| 6 | Pairs of disposable gloves |
| 5 | Bottles of Etching solution, 240 ml |
| 2 | Resealable bags, 9x12" |
| 1 | Package of Copper Chloride paper, 50,000 ppm |
| 1 | Battery harness with light bulb |
| 1 | Bottle of Clay, 500 cc |
| 1 | Bottle of Gravel, 500 cc |
| 1 | Bottle of Sand, 500 cc |
| 1 | Bottle of Potting soil, 500 cc |
| 1 | Drop control bottle of Red Food Coloring solution |
| 1 | Forceps |
| 1 | MSDS (Material Safety Data Sheet) set |
- Number of students
- 160
- Number of groups
- Maximum 8 groups per period
This module has 8 activities which will require 12 to 15 ~50-minute class periods to complete. SEPUP modules employ the 4-2-1 model: each student is part of a team of 2 and each team partners with another team to form a group of 4 that shares some equipment.
