How does charcoal filter out stuff from water?



How does charcoal filter out stuff from water?

In: Physics

Besides normal old filtering by catching big stuff like a net, activated charcoal has tiny pores in it. The tiny holes grab up stuff in the water and entrap it. Eventually the holes get filled up and it doesn’t work so well so you need a new filter. One gram of the stuff can have a surface area of 3,000 square meters according to wikipedia. That’s nearly half a football field. Lot’s of little holes for stuff to get caught in.

Charcoal is wood birned without air, and what that does is burns the firbers of the wood in such a way that it leaves the food filled with holea wich work well in filtering things fromater and air

Charcoal is very porous, meaning it has a large surface area that the water can come in contact with.
This then means that impurities can react and bind with the charcoal, removing them from the water.
After some time all the charcoal surface will be occupied by the impurities and the filter has to be replaced.

Adsorbtion and absorbtion, as well as mechanical filtration and even biological filtration.

Mostly adsorbtion tho

Bigger stuff gets caught in all the tiny nooks and crannies just like any mesh filter.

But pure carbon is also highly reactive and will catch some stuff through chemical adsorption. This is why carbon is used for a lot of air filtration systems, as the fumes are tiny enough to slip through and physical media.