Which term describes the binding of a contaminant to another material?

The term that describes the binding of a contaminant to another material is adsorption. In this process, contaminants adhere only to the surface of a material rather than being absorbed into its bulk. This surface phenomenon is crucial in applications such as filtration, water treatment, and soil remediation, where contaminants need to be removed from water or air by adhering them to the surface of an adsorbent material.

In contrast, absorption refers to a process where the contaminant is taken into the volume of another material, resulting in a more thorough integration than what occurs in adsorption. Retention typically refers to the ability of a material to hold onto substances, which may not necessarily involve the binding process. Desorption is the reverse of adsorption, pertaining to the release of a substance that was previously adsorbed, thus highlighting that adsorption specifically involves the binding of contaminants to surfaces.