Intervention
Adsorption
Part of: Activated carbon adsorption
Also: adsorptions, sorption, gas-phase filtration, carbon filtration
Removing a gas by binding its molecules to the surface of a solid. It is how every gas-phase air cleaner works, and it is a finite process: the surface fills, the removal stops, and what was captured can be released again.
What it is
A particle filter works by interception: the particle is physically caught in a mesh of fibres and stays there. A gas molecule passes through such a mesh untouched, so removing gases needs a different principle, and adsorption is it — the molecule sticks to a solid surface, held by weak attraction, in the pores of a material with an enormous internal area such as activated carbon.
Three properties follow from that mechanism and they explain nearly every disappointing result. Capacity is finite: once the surface is covered the filter passes what it used to catch, without any change the user can see. Binding is selective: heavier and less volatile compounds are held well, while small polar molecules such as formaldehyde are held poorly unless the medium is chemically treated. And binding is reversible: a warmed or saturated bed releases its load back into the room.
Contact time decides the rest — air moved quickly past a thin bed is barely cleaned at all.
What the studies report
| Linked to | Effect | Population | Study design | Source | Checked |
|---|---|---|---|---|---|
| Formaldehyde (CH₂O) | other 50.5 | — · test chamber | chamber tests of sorptive building materials (Celite siding, moisture-control plasterboard, low-emission paint) at controlled temperature and humidity with formaldehyde supplied at 0.1 and 0.2 ppm, adsorption rates and re-emission measured over 72 to 96 h | F-0291 Huang et al. Efficiency and performance tests of the sorptive building ma… (2019) | machine |
| Formaldehyde (CH₂O) | other 53.8 | — · test chamber | chamber tests of sorptive building materials (Celite siding, moisture-control plasterboard, low-emission paint) at controlled temperature and humidity with formaldehyde supplied at 0.1 and 0.2 ppm, adsorption rates and re-emission measured over 72 to 96 h | F-0292 Huang et al. Efficiency and performance tests of the sorptive building ma… (2019) | machine |
Each row is one Finding — a sentence as printed in one study, recorded with its page in the Coridum Knowledge Base. Follow the Finding number for the exact wording and the citation. Checked says who verified the row: machine means every automatic check passed and the surrounding text was read; person means someone read the sentence in the document. Rows are re-checked by a person over time. The studies are curated in the Coridum Knowledge Base; the reading of them together is a Claim, shown separately.
Identifiers
- MeSH
- D000327
Cite this page
Coridum Research. Adsorption. Coridum Knowledge G-0178, 16 September 2026. https://coridum.com/k/G-0178/