Water Filtration Lab
The purpose of this activity is to simulate nature's water filtration system by devising a system that will filter out both visible and invisible pollutants from water.
Water is necessary to all living things. Earth is unique in our solar system having about 70 % of its surface area covered with water. Of this water, only about 3% is potable (fit for human drinking). Of this three percent, about 79% is tied up in glaciers and sea ice leaving approximately 2.5% of Earth's water available for use by living organisms including humans. This amount of available drinkable water is further reduced by the introduction of pollutants to our water cycle. Clean water is not a limitless resource.
Pre-lab Questions
1. Define water pollution?
2. Does the definition specify any particular compounds or substances? Why or why not? What is the key
feature in deciding whether or not water is polluted?
3. What is a pollutant?
4. Create a list of several categories of materials or factors that may make water unsuitable for a given use.
Materials:
| beakers | dirty water |
| rubber bands | filter paper |
| nylon mesh | ring stand |
| sand | test tubes |
| charcoal | graduated cylinder |
| cotton balls | water |
Procedure:
Day 1:
A. Using the available equipment, devise a filtration system that you will use to "clean" your dirty water sample.
5.Write out, in detailed step-by-step instructions, how you will use the lab materials to filter the water sample. (Each group should have one set of instructions).
6. Sketch your filtration system set-up and label the parts. (Each group should have one sketch).
Day 2:
B. Using your proposed filtration system, make your water sample as clean as you can.
C. Make any adjustments to your model that are necessary in order to cleanse your water sample.
7. Was your original filtration system successful?
8. Describe any adjustments you made to your original model.
9. Were you able to remove all impurities?
10. What were some of the limitations of your system?
11. How could you tell if your water was purified? (HINT: What physical and/or chemical changes took place that would indicate that you accomplished your goal?)
12. What kinds of tests could you perform on your filtered water to prove that it had been cleansed?
13. Distinguish between "presence" and "concentration." Which is the most important factor in determining water pollution? What is meant by threshold level?
14. What are the two objectives of water purification?
You may have to use outside resources (internet or community) to answer the following.
15. Describe a water purification system that could be used in a municipal area.
16. What is/are the main source(s) of drinking water in Quispamsis?
17. What kinds of tests are done on the water supply in Quispamsis to meet health and safety standards?
18. What agency sets the criteria for safety standards?