Charcoal, coal, the difference is fire has been applied already correct? I Eons of water flowing through the soil, through around and under coal deposits, they do not get polluted or ruined. Coal in water, big threat...lol.
Charcoal is wood (or other woody substances each having its own properties)which has been charred. Activated charcoal is that which has been treated with steam to increase the surface area. The charcoal adsorbs (collects on the surface) contaminates, as either gas or liquid passes over under around and thru.