Adsorption (Latin: adsorbere – to attract) is the attraction of substances to solid surfaces. The adhesion that occurs can be both chemical and physical. Therefore the term adsorption is divided into ‘physiorption’ and ‘chemisorption’. The adsorbed substance is called adsorbate, the adsorbing body is called adsorbent.

Activated carbon is often used as an adsorbent. Surface-rich silica gels have similar properties.