Modified activated carbon is disclosed for use in water treatment. In at least some embodiments, activated carbon may be treated with a positively-charged surfactant, i.e. a quaternary ammonium-based surfactant, to promote the removal of poly- and perfluorolkyl substances from water.

Modified activated carbon is disclosed for use in water treatment. In at least some embodiments, activated carbon may be treated with a positively-charged surfactant, i.e. a quaternary ammonium-based surfactant, to promote the removal of poly- and perfluorolkyl substances from water.

An activated carbon regeneration method of the present invention is for eluting gold from activated carbon on which the gold has been adsorbed and thereafter recycling, in adsorption of the gold, the used activated carbon from which the gold has been eluted, the method including: washing the used activated carbon with an acidic washing liquid, alkaline washing liquid or neutral washing liquid; and when the used activated carbon is washed with the acidic washing liquid, keeping the acidic washing liquid after the washing in an acidic region, or when the used activated carbon is washed with the alkaline washing liquid or neutral washing liquid, keeping the alkaline washing liquid or neutral washing liquid after the washing in an alkaline region or neutral region.

An activated carbon regeneration method of the present invention is for eluting gold from activated carbon on which the gold has been adsorbed and thereafter recycling, in adsorption of the gold, the used activated carbon from which the gold has been eluted, the method including: washing the used activated carbon with an acidic washing liquid, alkaline washing liquid or neutral washing liquid; and when the used activated carbon is washed with the acidic washing liquid, keeping the acidic washing liquid after the washing in an acidic region, or when the used activated carbon is washed with the alkaline washing liquid or neutral washing liquid, keeping the alkaline washing liquid or neutral washing liquid after the washing in an alkaline region or neutral region.

A carbon-based porous material microscopically exhibiting a three-dimension 1 cross-linked net-like hierarchical pore structure, a specific surface area of 5002,500 m.sup.2/g and a water contact angle greater than 90. The surface of the carbon-based porous material has a through hierarchical pore structure with mesopores nested in macropores and micropores nested in mesopores, the content of mesopores is high, and there are more adsorption activity sites exposed on the surface of the material, so that the diffusion path for organic gas molecules in the adsorption process is shortened. At the same time, the absorption and desorption rates may also be accelerated and the desorption temperature may be lowered. Furthermore, benefits result for solving the desorption and recovery problems of organic gas molecules. Moreover, the defects of ordinary porous carbon materials being easily hygroscopic, having a weakened capacity to adsorb target gas molecules in a humid environment, etc. are further effectively solved.

A carbon-based porous material microscopically exhibiting a three-dimension 1 cross-linked net-like hierarchical pore structure, a specific surface area of 5002,500 m.sup.2/g and a water contact angle greater than 90. The surface of the carbon-based porous material has a through hierarchical pore structure with mesopores nested in macropores and micropores nested in mesopores, the content of mesopores is high, and there are more adsorption activity sites exposed on the surface of the material, so that the diffusion path for organic gas molecules in the adsorption process is shortened. At the same time, the absorption and desorption rates may also be accelerated and the desorption temperature may be lowered. Furthermore, benefits result for solving the desorption and recovery problems of organic gas molecules. Moreover, the defects of ordinary porous carbon materials being easily hygroscopic, having a weakened capacity to adsorb target gas molecules in a humid environment, etc. are further effectively solved.

The disclosure provides for methods of oxidizing carbide anions, or negative ions, from salt like carbides at low temperatures below about 600 C. In another aspect, the disclosure provides for reactions with intermediate transition metal carbides. In yet another aspect, the disclosure provides for a system of reactions where salt-like carbide anions and intermediate carbide anions are oxidized to produce pure carbon of various allotropes.

The disclosure provides for methods of oxidizing carbide anions, or negative ions, from salt like carbides at low temperatures below about 600 C. In another aspect, the disclosure provides for reactions with intermediate transition metal carbides. In yet another aspect, the disclosure provides for a system of reactions where salt-like carbide anions and intermediate carbide anions are oxidized to produce pure carbon of various allotropes.

A nanofiber yarn that includes a plurality of nanofibers twisted into a yarn along an alignment axis. The nanofibers of the plurality of nanofibers have a ratio of nanofiber length to nanofiber circumference of at least 50. The yarn has a helix angle measured relative to the alignment axis of from 5? to 30?. The yarn has tensile strength of at least 280 MPa. A nanofiber fabric that includes a first sheet of multiwalled nanotubes and a second sheet of multiwalled nanotubes on the first sheet of multiwalled nanotubes. The multiwalled nanotubes of the first sheet are aligned in a first direction. The multiwalled nanotubes of the second sheet are aligned in the first direction. The first sheet and the second sheet are aligned so that the multiwalled nanotubes of the first sheet and the second sheet are both aligned in the first direction.

A nanofiber yarn that includes a plurality of nanofibers twisted into a yarn along an alignment axis. The nanofibers of the plurality of nanofibers have a ratio of nanofiber length to nanofiber circumference of at least 50. The yarn has a helix angle measured relative to the alignment axis of from 5? to 30?. The yarn has tensile strength of at least 280 MPa. A nanofiber fabric that includes a first sheet of multiwalled nanotubes and a second sheet of multiwalled nanotubes on the first sheet of multiwalled nanotubes. The multiwalled nanotubes of the first sheet are aligned in a first direction. The multiwalled nanotubes of the second sheet are aligned in the first direction. The first sheet and the second sheet are aligned so that the multiwalled nanotubes of the first sheet and the second sheet are both aligned in the first direction.