Water Filters

In class we have been studying about pollution and how we could prevent it. Our main project was to build a water filter that could actually work (But of course the water that comes out of it wouldn’t actually be drinkable). We started by reading a book called “A Long Walk to Water” it’s about two different characters and one has to fetch water everyday while the other is a refugee and grows up to be an environmental engineer. We then read a picture book called “Saving Salila’s Turtle”, it was about a girl Salila who lives near the Ganges River in India and about how she wants to make the water cleaner. We answered many questions about the book and learned many vocabulary words related to pollution and the environment.

Then we started examining three different bottles of water that were all filled with different contaminants and we had to write down our observations about the water. We also made a chart about the differences and the similarities between the three bottles of water and the Ganges River. After we were finished with that we started to talk about what kind of materials that would “work the best for filtering different types of contaminated water”. Each team then got a dirty bottle of water and materials, our teacher instructed us that we had to create a filter with the specific materials. (I wasn’t here when this happened) then everybody were given reflection questions about the materials and observations that we had documented. The next day we reviewed the reflection questions and we talked about what kind of things make a filter great. We then had to decide as a team four main things that we had to include in our filter. In the end we came up with: reusable, reliable, efficient, and safe.

We then got our materials and the dirty water back. Now we were building the actual filter but these were probably not going to be our final filters since we would probably make many changes to the filter before we thought it was finished. Our teacher put out five different bottles of water. They were all different shades and were ranked on how dirty they were. Five was the most dirtiest and one was the cleanest. She said that after we filtered our water we would rank it by comparing the water to the five bottles. But first, she told us that we had to write down our goal (the number that we wanted after our water went through the filter) and our group wrote a 1 / 2. We also had to write all the materials that we chose and why we thought they would work well. The materials that we chose were:

  • Sand
  • Gravel
  • Screan
  • (maybe) strainer
  • (maybe) wipes

(In the end we thought about it and decided that we would probably us the wipe)

We then started building our filters with the materials that we thought would work the best. Our filter started with a screen stuffed in the bottle/filter and then another tiny net on top of that. We then put in gravel first then sand because we didn’t want the sand to leak out and we found out last time that the gravel acts kind of like a wall preventing the sand from leaking. On top of the whole bottle/filter was a wipe that would block out particles completely (we hoped). We taped the filter to a table leg and poured a bit of the dirty water into a cup. Our teacher recommended that we document the process with our phones by taking pictures and videos so I was recording the whole filtration process. (As we hoped) the wipe completely blocked out all the particles in the water and then we waited for the rest of the system to be done with filtering the water. The speed was definitely not that fast, but it wasn’t really that slow either so we were fine with the speed but we would definitely think about improving that in our second design. In the the end when the filtration was finally done, we compared our filtered water to the five bottles of water and we got a 2 ½. We got 2 ½ because the 2 was that the water in the bottle had particles, but our water didn’t and we got the ½ because the color wasn’t as light. In the end when we already ran through our second run and answered a few questions just because we were bored we sniffed our filtered water and it smelled exactly like tea. We asked our teacher if there were tea leaves in our contaminated water (since the water was so dark we couldn’t even see what was in there). She didn’t tell us and left us very confused and excited.

After the end of the experiment, we were all tired but excited because the clean up had to take a VERY long time (or I at least thought) but we were excited because we were proud of how our filtered water turned out. And because we wanted to do more experiments since it was so fun