Why Activated Carbon Can Clean Water
Steam-treated carbon works less like a fine sieve than a vast chemical landing surface. During activation, steam opens and enlarges tiny spaces inside the carbon. Water flows through the resulting network, exposing dissolved substances to the carbon’s pore walls.
Many contaminants stick to those walls through adsorption: molecules attach to a surface rather than soak into the material. The carbon’s enormous internal area gives them many places to cling, even though the filter itself may look like an ordinary dark cartridge.
What the Pores Can—and Cannot—Do
A contaminant’s chance of sticking depends on its chemical properties and on how the filter is made. Activated carbon is particularly useful for reducing substances that readily attach to carbon, including many compounds that affect taste or odor. It does not remove every kind of contaminant equally well; some dissolved minerals and other substances may pass through unless the filter uses additional treatment materials.
The filter also has a finite capacity. As more contaminants occupy the available surface, fewer open sites remain, and eventually some substances can pass through. That is why carbon filters need replacement according to their design and use: the carbon can look unchanged even after much of its useful surface has been occupied.
