Walk-In Take out notebook, folder, pencil box. Copy this week’s agenda. AZ Water Web Quest

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.

A watershed helps to collect water, to clean the water, and to send it downstream to where it is needed. It provides habitats for animals and humans. A healthy watershed has places for water to sink into the soil, like forests, grasslands and farms.

In an UNHEALTHY watershed, rain cannot be absorbed (due to pavement, concrete, etc.), may overflow from water pipes and sewer treatment plants.

A rain garden helps to filter water because Water sinks in more slowly, so impurities like oil can collect and be removed. It slows water down from getting to rivers or streams, so less pollutants enter the rivers.

In nature, water is filtered through layers of soil, sand, rock, and other natural materials like leaves. Some “good” bacteria help to decompose certain chemicals. If nature can’t “keep up” with cleaning the water, humans have to find ways to treat it and clean it.

Today’s Learning Goals TSWBAT build a water filter that can clean a sample of dirty water.

Two Steps to Filtering Remove SEDIMENTS (large pieces). Add chemicals to remove other chemicals, and/or to 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

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. 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?)