According to one aspect of the present invention, a pressure swing adsorption (PSA) device includes an adsorption tower configured to introduce hydrogen gas and adsorb impurity components in the hydrogen gas by using a pressure swing adsorption (PSA) method, an adsorbent of one layer made of activated carbon or an adsorbent of two layers in which activated carbon and zeolite are stacked being disposed in the adsorption tower, the hydrogen gas containing carbon monoxide (CO) of 0.5 vol % or more and 6.0 vol % or less and methane (CH.sub.4) of 0.4 vol % or more and 10 vol % or less as the impurity components; and a densitometer configured to detect a concentration of CO in the hydrogen gas discharged from the adsorption tower, wherein the impurity components are adsorbed and removed to cause the CO concentration measured by the densitometer to fall below a threshold.

Sorbent materials that are treated with ions, salts, oxides, hydroxides, or carbonates of calcium, magnesium, strontium, or barium are useful in removing perfluoroalkyl and polyfluoroalkyl substances (PFAS), perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), 2,3,3,3,-tetrafluoro-2-(heptafluoropropoxy)propanoate and heptafluoropropyl 1,2,2,2-tetrafluoroethyl ether, and similar compounds from liquids and gases are disclosed. The sorbent materials with the disclosed treatments offer improved performance as measured against untreated sorbent materials.

The invention provides methods for regenerating activated carbon that have been used in absorbing per- and polyfluoroalkyl substances (PFAS) in aqueous solution. In these methods, the activated carbon is treated with a solution of base in alcohol, which has been found to impart superior properties to the activated carbon.

There is described a method of making an adsorbent material comprising mixing first particulate material with a second material, homogenising the mixture of the first and second materials, incorporating an impregnating or coating material capable of carbonisation, and carbonising the mixture. Also described are adsorbent materials manufactured according to said method and the use of such adsorbent materials in the treatment of a contaminated liquid. Further described is a method of removing contaminants from a quantity of contaminated liquid.

A composite of polyurethane foam grafted with carbon nanofibers is described. This composite foam may be made by contacting and drying a polyurethane foam with a suspension of carbon nanofibers and then drying. Additional carbon nanofiber layers may be added with repeated contacting. The composite film has a high surface area of 276 m.sup.2/g and a hydrophobic character that may be exploited for separating an oil phase from water.

Certain embodiments described herein are directed to systems and methods that can be used to analyze species in a fluid stream. In some configurations, a sorbent tube effective to directly sample aromatics and/or polyaromatics in a fluid stream is described.

An activated carbon device for adsorbing solvent from a flow of air is regenerated by feeding heated inert gas to the activated carbon and by applying a reduced pressure to the heated activated carbon.

The present invention discloses a method for initiating a graphene oxide (GO) through reduction by a reductant to controllably release organic compounds, comprising the following steps: (1) mixing GO and a buffer solution; (2) further mixing with a sewage containing organic contaminants; (3) conducting solid-liquid separation, mixing the solid phase and the pure, introducing and N.sub.2; (4) further adding the reductant; (5) conducting sequential batch kinetics experiment. The present invention utilizes the size effect and polarity control of GO to selectively adsorb aromatic organic contaminants in sewage and fully transfer the selectively adsorbed organic contaminants from a large amount of sewage to a small amount of pure water by initiating using the reductant, and no extraction of the organic phase is required, the time for purification is reduced, and the energy consumption for purification is also reduced.

A device for the dehumidification of air in a processing space of a dishwasher is connected in an air-conducting manner to the processing space of the electric appliance. The device includes carbon-based fibres, which are designed as a fibre unit. The fibre unit is arranged between the processing space or an air duct connected thereto and at least one dehumidification chamber of the device. The carbon-based fibres absorb moisture from the air of the processing space, which they then release again in the dehumidification chamber. During this process, the carbon-based fibres are moved backwards and forwards between the processing space or air duct and the dehumidification chamber, preferably by slow rotation on a support.

A carbon dioxide recovery apparatus has: a separator that separates carbon dioxide from a gas and discharges a residual gas from which carbon dioxide has been removed; a dryer having a hygroscopic agent for drying the gas to be supplied to the separator; and a regeneration system which supplies the residual gas to the dryer as a regeneration gas for regenerating the hygroscopic agent in the dryer. The separator utilizes adsorption/desorption of carbon dioxide to an adsorbent caused by pressure fluctuation. A supplement system supplies a supplement gas from an outside to the residual gas depending on a flow rate of the residual gas discharged from the separator such that a flow rate of the regeneration gas is a predetermined rate.