Straining out the Dirt
Students build their own water filters.Copyright 2006 Nyaya Health via Flickr https://www.flickr.com/photos/nyayahealth/6892484355/
Students groups build water filters using activated carbon, cotton and other materials to clean a "dirty" water sample made from chocolate powder added to tap water. They test and make observations of filter effectiveness, suggesting material and layering design improvements. They see how their filtering process compares to the drinking water treatment processes designed by engineers to provide communities with clean water supplies after natural disasters.
Environmental and civil engineers design systems to process communities' water supplies to make them clean enough for people to drink. Depending on the starting water quality, most municipal water treatment systems involve many steps to eliminate the contaminants that could make people sick. Often, the treatment process includes the use of filters of sand and activated carbon to remove particulate matter and certain bacteria just before the water is disinfected with chlorine. Engineers also design water filtration devices to help communities affected by natural disasters.
After this activity, students should be able to:
- Design and build a model filter and compare it to processes used by engineers in drinking water treatment.
- Test and make observations on filter effectiveness.
- Use data from observations to construct a reasonable explanation of drinking water treatment through a filter.
- Describe how drinking water filters can help improve the drinking water quality of a community.
- Explain how drinking water filters can be used in the aftermath of a natural disaster.