“Makeshift water filter” experiment
How to make a water with charcoal and sand
You know the drill: you’re out camping with friends, and you don’t have enough water. In this experiment, you’ll learn how to purify water from the nearest puddle. You only need a plastic bottle, sand and a few burnt logs.
Be sure to boil the water after filtration. Since water may contain heavy metals, it is recommended for utility purposes, and should be consumed if absolutely necessary.
Reagents and equipment:
- charcoal (100 g);
- sand (300 g);
- plastic bottle with a lid;
- utility knife;
- cotton wool;
Cut the bottom off of the plastic bottle. Unscrew the lid of the bottle, make a hole in it with the awl and place cotton wool in the lid. Close the bottle and turn it upside down. Pour layers of sand and charcoal in the bottle. The more layers, the more effective the purification will be. The filter is ready!
Dirty water contains many organic and mineral impurities, as well as various insoluble particles of dust and earth. The sand purifies the water of insoluble particles. Charcoal has good adsorption and so adsorbs organic and mineral impurities. However, this filter has a considerable drawback: it does not purify water from bacteria and heavy metals. So after filtration the water must be boiled well.