How do you think water gets cleaned in nature? Walk-In Take out notebook, folder, pencil box and agenda. Copy the question and answer in sentences: How do you think water gets cleaned in nature?

Water Filters

How does Nature clean its own water? Watch this video clip about the natural way water is cleaned before returning to the earth.

Set up for Cornell Notes Narrow column and wider column

Healthy Watershed A watershed helps to collect water and to send it downstream. A healthy watershed has places for water to sink into the soil, like forests, grasslands and farms.

Unhealthy Watershed Rain cannot be absorbed (due to pavement, concrete, etc.), and may overflow from water pipes and sewer treatment plants.

Nature Cleans Water Water is filtered through layers of soil, sand, rock, and other natural materials like leaves. Some “good” bacteria help to decompose certain chemicals.

What if Nature can’t keep up? If nature can’t “keep up” with cleaning the water, humans have to find ways to treat it and clean it.

Two Steps to Filtering Remove SEDIMENTS (large pieces). Add chemicals - A FLOCCULANT makes particles clump together, so they can be filtered out, - Good chemicals can remove other chemicals , and/or kill germs.

What pollutes our water? Observe this container of dirty water…

Natural pollutants, like sand, leaves, and grass. We have added… Natural pollutants, like sand, leaves, and grass. Human-made pollutants, like oil, chemicals , acids, metal, paper, and others. How will we clean this??!!?

Design a Filter Work in a group of 3. Each group gets: 4 plastic cups 1 coffee filter Choice of 3 filter materials from the demo table. 12 push pins

Brainstorm how to build your filter! Don’t poke any holes yet, but plan how you might use your cups and other materials!

Observe how to build your filter Notice which cups need holes in the bottom, and where to put the push pins!

Build your filter! When you are done, get a sample of dirty water from Mrs. Ryan. Pour it through your filter. Observe whether it seems cleaner at the end. Think of one change you could make that would IMPROVE your filter. TRY IT! Pour your water from the bottom cup back through and see if it is even better.

Testing the Water - pH Test the pH of water – Is the water acid or alkaline? Acid – will taste sour Alkaline – will taste salty Neutral – no taste To test, dip a strip for 2 seconds. Wait 1 minute. Then compare your color to the bottle under the doc cam.

Testing the water - Nitrate Nitrates are chemicals in groundwater. Can be very harmful to babies. For older people, the presence of nitrates can mean other harmful chemicals are present. To test, dip a strip for 2 seconds. Wait 1 minute. Then compare your color to the bottle under the doc cam.

Finish your lab write-up sheet. Explain what you found out. Do your diagrams. Discuss what you would try to improve on. Explain some of the limitations of your water filter. (How effective was it, and why?)