Hobbies And Interests
Water Plant Techniques: Aeration, Coagulation
Middle school-aged children can be exposed to the process used by water treatment plants by conducting an experiment that turns unfiltered water into filtered water. The experiment mimics the steps used to treat water: aeration, coagulation, sedimentation and filtration. Add approximately 1.5 liters of "swamp" water that contains impurities to a 2-liter bottle. Let the students observe how unclean the water looks and smells. Aerate or add air to the water by quickly pouring it between two cut-off plastic bottles, allowing the gases to escape. Add potassium aluminum sulfate, which will cause dirt and other particles to stick together and be removed.
Water Plant Techniques: Sedimentation, Filtration
Gravity will pull the clumped particles to the bottom of the container during sedimentation. This is easily observed by the students. To finish the experiment, attach a coffee filter to the bottle and pour the water through the filter into a separate container; the coffee filter will only allow the clean water to filter through. Keep some of the original water in the container so students can compare the new, filtered water with the untreated water.
Experiment for Preschoolers
Young children can learn about water filtration through a simple experiment using a funnel lined with a paper towel. Put some clean sand into the cone and then pour muddy water through the funnel. The sand and paper towel will act as a filter and catch the impurities in the water, allowing the resulting product to be clean water.
Water Filtration Device
There are several common items that can be used as a water filter in experiments. These items are simplified versions of the devices used in a water treatment plant and can show how water is treated. Items that can filter water include a coffee filter, pantyhose and cotton. To illustrate unfiltered water, add items such as food coloring (representing chemicals), soil, soy sauce (oil) and torn paper (litter).