Provided is a mercury adsorbent that can efficiently adsorb and remove mercury and/or a mercury compound contained in a liquid hydrocarbon and can suppress corrosive action even when used for a long time. The mercury adsorbent comprises an activated carbon including a mineral acid supported thereon, the activated carbon having a specific surface area of 1000 m.sup.2/g or larger and a volume of micropores of 80 cm.sup.3/g or larger, each of the micropores having a pore radius of 8 Å or smaller, and the mercury adsorbent has a moisture content of from 0.1 to 3 wt %.

Described herein is a an adsorbent and/or absorbent composition, a method of preparing the adsorbent and/or absorbent composition, and method of treating a fluid stream with the adsorbent and/or absorbent composition. Alumina and carbon are combined with polyacrylamide (PAM) powder and water in preferred proportions and impregnates such as Group 1A metal hydroxides. Group 7A salts of Group 1A metals optionally can be added.

Described herein is a an adsorbent and/or absorbent composition, a method of preparing the adsorbent and/or absorbent composition, and method of treating a fluid stream with the adsorbent and/or absorbent composition. Alumina and carbon are combined with polyacrylamide (PAM) powder and water in preferred proportions and impregnates such as Group 1A metal hydroxides. Group 7A salts of Group 1A metals optionally can be added.

A filter for a liquid purifier, comprising: a filter housing having an inlet to receive water and an outlet to discharge the water; and a filter module provided in the filter housing, and configured to purify water introduced through the inlet, and to provide the purified water to the outlet, wherein the filter module includes a carbon block having a hollow tube shape by mixing activated carbon, a binder, ferric hydroxide, and titanium oxide, and the binder is mixed at a ratio of 13% to 23% by weight.

A filter for a liquid purifier, comprising: a filter housing having an inlet to receive water and an outlet to discharge the water; and a filter module provided in the filter housing, and configured to purify water introduced through the inlet, and to provide the purified water to the outlet, wherein the filter module includes a carbon block having a hollow tube shape by mixing activated carbon, a binder, ferric hydroxide, and titanium oxide, and the binder is mixed at a ratio of 13% to 23% by weight.

Described herein is a functional graphene composition comprising a graphene scaffold and one or more metal chelating functional groups covalently bonded to the graphene scaffold and a porous substrate that includes the functional graphene composition. Also provided is a method of removing dissolved metals from an aqueous liquid, such as, acid mine drainage.

Described herein is a functional graphene composition comprising a graphene scaffold and one or more metal chelating functional groups covalently bonded to the graphene scaffold and a porous substrate that includes the functional graphene composition. Also provided is a method of removing dissolved metals from an aqueous liquid, such as, acid mine drainage.

A system and method for water purification by capture of contaminants in an aqueous mixture is described herein. A system and method for regenerating the capture system is also described. An integrated capture and regeneration system and method is also described including a separation vessel that houses a capture bed and optionally an electrode in electrical contact with the bed with a power source for applying a voltage to the electrode. The applied voltage enhances capture of the contaminant from aqueous liquid on the capture bed and modulation of the applied voltage enhances release of contaminant on the capture bed into aqueous wash liquid to regenerate the bed. The aqueous wash liquid may contain a counter ion that binds to the contaminant forming an aggregate contaminant phase that separates from the aqueous wash liquid.

A system and method for water purification by capture of contaminants in an aqueous mixture is described herein. A system and method for regenerating the capture system is also described. An integrated capture and regeneration system and method is also described including a separation vessel that houses a capture bed and optionally an electrode in electrical contact with the bed with a power source for applying a voltage to the electrode. The applied voltage enhances capture of the contaminant from aqueous liquid on the capture bed and modulation of the applied voltage enhances release of contaminant on the capture bed into aqueous wash liquid to regenerate the bed. The aqueous wash liquid may contain a counter ion that binds to the contaminant forming an aggregate contaminant phase that separates from the aqueous wash liquid.

A photocatalyst filter is provided. The photocatalyst filter includes: a base in which an internal space is formed. The internal space is permeable to fluid, and a plurality of photocatalyst beads are provided in the internal space, wherein a surface of the internal space is reflective.