how does activated charcoal work in water filters?

Answer 1

Activated charcoal is charcoal that has been steam treated to remove all degradable organic matter from the charcoal, essentially turning the charcoal into a sponge. A handful of activated charcoal may have several acres of surface area!! This huge amount of surface area allows the adsorption of large quantities of organic chemicals, heavy metals, and chlorine. Activated charcoal also removed taste and odor compounds such as geosmin and mib.

Answer 2

It absorbs impurities. When it is full of impurities, it must be replaced with clean activated carbon.