As part of our FLL Jr project, we conducted an experiment to check how the water filtration system work. We made a very simple filter and checked if it would clean a dirty water.
What will you need?
- small plastic bottle
- two jars
- elastic bands
- first-aid gauze
- cotton pads
- some dirty ground from outside
- a microscope
First, we prepared a dirty water that would need to be filtered. We put some dirt from the yard into a small jar, added water, stirred well with a wooden stick and left it aside.
To make a filter we cut the bottom of the plastic bottle. We put some gauze around its neck and secured it with an elastic band. We also placed cotton pads inside the neck for extra protection. Then we added the sand. We put few elastic bands around the bottle and placed our brand new filter in a big jar.
When everything was ready, it was a time to check if our construction works. Rascals poured some dirty water into the plastic bottle and we observed how after few seconds it started to tap through the neck. With our bare eye, we could see it has changed its colour – from completely dark to just a bit dirt-yellowish.
But we wanted more concrete proof. We prepared samples of both dirty and filtered water to check them under the microscope. And to our amazement, while the dirty water was definitely dirty, the filtered water was… clean! It wasn’t obviously drinkable clean, but we could not spot any contamination.