# adsorption

/ədˈsɔɹpʃən/ (US) · /ɐdsˈɔːpʃən/ (UK) · CEFR C1 · Noun

Source: https://englishreference.com/word/adsorption
Updated: 2026-05-19

## Definition

the process where a substance sticks to the surface of another material. It is like when a sponge soaks up water, but it happens at a very small level you cannot see.

For teachers: the process by which molecules of a gas or liquid are held on the surface of a solid or liquid. This is distinct from absorption, where the substance is taken into the bulk of the material.

## Examples

- The filter uses adsorption to remove impurities from the water.
- In environmental science, the adsorption of heavy metals onto activated carbon is a common method for water purification.
- The efficiency of the catalytic converter depends on the adsorption of exhaust gases onto the surface of the platinum catalyst, which facilitates the chemical reaction necessary for emission control.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.