SOLUTION CHEMISTRY INQUIRY PROJECT
Background Information
Water, as you know, is the most abundant substance on Earth’s surface. Unfortunately, there is more than enough water in some places, but not enough in others. As well, because water is used and re-used, and because it is such a powerful solvent, it is easily polluted. Canada, with less than 1% of the world’s population, has 22% of its fresh water. So, in most regions of our country, the quality of water is usually of greater concern than the quantity available. In this section, you will examine factors that affect water quality. You will also study some of the reactions that make polluted water safe and fit to drink.
The federal government assesses the health risks of specific substances in drinking water. Guidelines for acceptable concentrations of each substance are then established in partnership with provincial and territorial governments. See Table below. These governments require water suppliers to meet the guidelines. Corrective action may be taken when guidelines are violated.
ONTARIO INCIDENT: Drinking water guidelines exist for microscopic organisms, such as bacteria and protozoans, as well as for chemicals. These guidelines were compromised in the town of Walkerton, Ontario, in 2000. Seven people died and about 2000 people became ill as a result of exposure to E. coli bacteria that were present in the town’s water supply. The maximum acceptable concentration for E. coli bacteria is zero organisms detectable in 100 mL of drinking water. To achieve this target, chlorine is commonly used to kill E. coli and other organisms in drinking water. Despite receiving two warnings from the Ministry of the Environment, the town’s water manager chose not to increase the concentration of chlorine in the water supply. As a result of this incident, the Ontario government drafted legislation to enforce strict adherence to water quality guidelines.
TASK: Write a research report in about 500 words, in which you will:
Explain the origins of pollutants in natural water
Identify the allowed concentrations of pollutants in drinking water
Explain the origins and consequences of water hardness
Outline methods for softening hard water
Describe the technology involved in purifying drinking water and treating wastewater
