Plasma-Activated Water (PAW)

Plasma-activated water is water that has been treated by exposure to a non-thermal plasma discharge, acquiring dissolved reactive species and a changed acid–base and redox character. It is the central subject of the source dossier recorded at Plasma-Activated Water: A source Dossier (Provisional Record), though that capture is incomplete and supplies no specific claims.

How it is produced

The general method is to bring a cold atmospheric plasma — an ionized gas near room temperature, generated by electrical discharge — into contact with a water surface or to bubble plasma-processed gas through water. Species formed in the gas phase cross into the liquid, where they dissolve and react. The discharge itself is described on Non-Thermal Plasma (Cold Atmospheric Plasma); the electrical-discharge basis connects the topic to electricity and physics.

What changes in the water

Three families of change are commonly described:

• Dissolved reactive species. Plasma treatment introduces reactive oxygen and nitrogen species (RONS) into the liquid. Typical members of this family include hydrogen peroxide, nitrite, nitrate, and peroxynitrite-related species. See Reactive Oxygen and Nitrogen Species (RONS).
• pH shift. When nitrogen oxides dissolve, they form nitrous and nitric acid, tending to lower the pH. The resulting acidity is part of what distinguishes PAW from untreated water.
• Redox potential. The pool of oxidising species raises the oxidation–reduction potential of the liquid.

Because the reactive species are short-lived, PAW is generally discussed as a freshly prepared treatment whose properties decay with time and storage.

Why it is of interest

The properties above are the reason PAW is studied in contexts where a short-lived, chemically active aqueous medium is useful — for example surface decontamination and agricultural treatment. The agricultural framing is recorded separately as Plasma Agriculture. This wiki does not, on the basis of the present source, assert any particular efficacy for any of these uses.

Evidence status

This concept page describes the subject as it is generally understood. It does not report results from the source dossier, because the ingested capture of that dossier contains no verifiable claims, no device specifications, and no trial data. Any efficacy attributed to PAW in archive material should be treated as a claim to be attributed, not a finding to be relied upon; see Patent as Evidence for the parallel caution about patent citations.

Related

• Non-Thermal Plasma (Cold Atmospheric Plasma) — the discharge that produces PAW.
• Reactive Oxygen and Nitrogen Species (RONS) — the proposed active agents.
• Plasma Agriculture — the application area.
• water, chemistry, agriculture — broad subject guides.