TCE Contamination and Cleanup Curriculum
Costs and Benefits of Solvent Use
Author: S. Stewart
Editor: Stephanie Nardei
Time: 2-3 class periods
Preparation
30 min
Time:
Materials: Per student group:
0.01M KMnO4 solution, 6 mL
Spot plate
0.1M HCl in dispenser, 1 mL
0.1M NaOH in dispenser, 1 mL
0.1M FeSO4*7H2O, 6 mL
Abstract
Students read information from the web to determine how polarity affects
solubility, commercial uses for solvents such as TCE, health hazards
associated with TCE, alternative solvents, and remediation techniques.
Students will answer questions on a student data sheet and perform a cost
and availability analysis of various solvents. Students perform a lab to
determine the best pH and mixing order for optimal breakdown of KMnO4 in
a simulation of a commonly used remediation technique.
Purpose
Students will explore the costs and benefits of the use of particular solvents such as TCE. They
will also determine the optimal conditions for the breakdown of KMnO4, a commonly used TCE
remediation technique.
Objectives
Students will be able to:
1. Explain the significance of polarity on solubility.
2. Describe several commercial uses for solvents such as TCE.
3. Describe several possible health concerns related to TCE.
4. Identify alternative solvents and assess their availability.
5. Compare costs and health benefits for TCE and alternative solvents.
6. Analyze costs and benefits of various remediation methods.
National Science Education Standards
Content
Concept 1 PO 2. Describe the environmental effects of the following natural and/or human-
caused hazards:
Concept 1 PO 2. Develop questions from observations that transition into testable hypotheses.
Concept 2 PO 1. Analyze the costs, benefits, and risks of various ways of dealing with the
following needs or problems: hazardous wastes
Concept 4 PO 2. Identify the indicators of chemical change, including formation of a precipitate,
evolution of a gas, color change, absorption or release of heat energy.
TCE Contamination and Cleanup Curriculum
Teacher Background
Production of TCE:
-TCE is manufactured at only a handful of plants in the US.
-PPG Industries obtains ethylene dichloride and reacts it with chlorine, hydrochloric acid
and oxygen to produce trichloroethylene.
-Dow Chemical reacts ethylene dichloride with chlorine alone to produce TCE and
tetrachloroethylene.
KMnO4 Lab: All reagents will be dispensed by drop. It is most convenient to provide them in
dropper bottles, or alternatively with dedicated pipettes.
KMnO4 stains badly, but is not harmful on the skin.
Goggles should be worn.
Related and Resource Websites
Wisconsin Dept of Health & Family Services Chemical Fact Sheet, trichloroethylene
http://www.dhfs.state.wi.us/eh/ChemFS/fs/TCE.htm
TCE on Wikipedia http://en.wikipedia.org/wiki/Trichloroethylene
ATSDR on TCE http://www.atsdr.cdc.gov/tfacts19.html
World of Molecules on TCE http://www.worldofmolecules.com/solvents/tce.htm
Activity
1. Teacher asks, “Why did the dye dissolve in ethanol but not water?” Students read about
solutions, solvents, and polarity and answer the question on the student activity sheet.
2. Students read about commercial solvent uses and answer questions on the student
activity sheet.
3. Students read about health concerns associated with TCE and alternative solvents.
4. Students analyze various solvents to compare price and health impact.
5. Students read about the various remediation methods and answer questions on the
student activity sheet.
6. Students perform a lab in which they investigate the effects of pH and order of mixing on
the efficiency of breaking down KMnO4. See student lab sheet.
Closure
Teacher prompts class discussion of questions on student activity sheet and discussion of lab
results.
Embedded Assessment:
Assess student responses on student activity sheet and lab sheet.
Homework
N/A