STEM Activity: Build Your Own Water Filtration (Water Filter Experiments) Goal of the activity: Help to save the environment. Learn the science of cleaning and reusing dirty water by conducting interesting water purification experiments. Build your own water filtration using the same method. Materials: - Large(ish) water/soda bottle Gravel or pebbles Sand Active carbon Filter paper / Cloth Cup/container Dirty water (half fill a small glass of water, add soil and oil to it and stir to make a brownish coloured mixture). Procedure: - Step 1: Simple BioFilter Materials The first step of this project is to build the biofilter. This is a simple but effective water filter suitable for filtration in developing countries to a water cleaner in the apocalypse. It is very easy to make, only requiring a few simple supplies. - - Step 2: Preparing the Bottle. Making the water bottle into a fill ready filter is easy. First, I cut the bottom off to make an area for water to be poured in. I then drilled three holes in the cap and screwed it back on. - Step 3: Filling the Filter Using the materials given (pebbles, gravel, cloth, filter paper, sand, active carbon) construct an effective filter mechanism in the bottle. HINT: Think about the size of the materials. - Step 4: Using the Biofilter Stand the bottle upside down on the top of the container. The biofilter is simple to use, just pour the dirty water into the top and watch it drip out the bottom in a crystal clear stream. One important maintenance piece is backwashing. Over time and use a filter will build up with the waste it filters out. To clear this out I held closed the bottom, filled the filter with clean water and let it overflow over the top for about five minutes until it seemed clear. Questions: 1- How clean is the water that runs into the container? 2- Why it is important to purify the water? 3- Is this water drinkable? Why? 4- List down the importance of water for living organisms.
