Question: Can we filter water in order to make it cleaner?

Natalie Lamb answered on 5 Mar 2019: last edited 5 Mar 2019 12:57 pm

We can filter water to make it cleaner, yes.

We can use all sorts of filters to remove things of different sizes from the water. If you think of it like the difference between a colander in a kitchen and a sieve in the kitchen. If you put water and rice into a colander, both the water and rice would fall through its big holes. But the sieve has smaller holes so the rice would stay in the sieve and only the water would pass through. A filter called microfiltration is like the colander and a filter called ultrafiltration is like the sieve, except they remove very small things like bacteria that can’t be seen without a microscope.

I thought this image from the Royal Society of Chemistry is good-