Should I Drink That?
What is an environmental engineer?Copyright 2007 The Iowa State Department of Agronomy, Wikimedia Commons http://commons.wikimedia.org/wiki/File:Field_Trip-_water_sampling.jpg
Students perform one of the first steps that environmental engineers do to determine water quality—sampling and analysis. Student teams measure the electrical conductivity of four water samples (deionized water, purified water, school tap water and a salt-water solution) using teacher-made LED-conductivity testers and commercially available electrical conductivity meters. They use multimeters to also measure the resistance of the samples. They graph their collected data to see the relationship between the conductivity and resistance. Then, all students measure the conductivity of tap water samples brought to school from their homes; they organize and average their data by sub areas within their local school district to see if house location has any relationship to the water conductivity in their community.
Environmental engineers are challenged to find solutions to environmental problems related to water recycling, waste disposal, public health, and air and water pollution. Water pollution is a particularly important concern because ongoing access to supplies of clean water is essential in all communities. Engineers test the water quality as a first step in making plans to remediate any contamination problems. While several methods exist to determine if water is polluted or not, conductivity testing is one of the preliminary and simplest ways to measure water quality.
After this activity, students should be able to:
- Explain different ways to determine the conductivity of water.
- Determine the relationship between conductivity and resistance.
- Analyze water conductivity with respect to the water sample location.
- Propose a way to treat water so that its conductivity is in the acceptable range.