A method for removing silica in salt water, including adjusting salt water containing silica ions to a pH of 9 or more, and then bringing the salt water into contact with a selective adsorbent for silica ions. Preferably, the salt water is passed through an adsorption tower filled with the adsorbent at an LV of 0.5 to 20 m/h. The adsorbent is a metal hydroxide adsorbent or a strongly basic anion exchanger having a glucamine group.

Hybrid sorbent on the base of anion-exchange polymeric matrix with HFO for selective sorption of arsenic characterized in that, HFO exists in matrix as particles, which at most are amorphous ferrihydrite, fraction of which is not less than 80%, preferably more than 90% from total mass of HFO.

The object of the invention and the technical result achieved with the use of the invention is to develop new hybrid sorbent with HFO with increased sorption kinetics of two arsenic forms As(III) and As(V) simultaneously.

Hybrid sorbent on the base of anion-exchange polymeric matrix with HFO for selective sorption of arsenic characterized in that, HFO exists in matrix as particles, which at most are amorphous ferrihydrite, fraction of which is not less than 80%, preferably more than 90% from total mass of HFO.

The object of the invention and the technical result achieved with the use of the invention is to develop new hybrid sorbent with HFO with increased sorption kinetics of two arsenic forms As(III) and As(V) simultaneously.

The present invention provides a filter which, even when raw water is subjected to high-speed treatment, enables achieving a high solute rejection ratio and a long solute filtration life and which exhibits a low water flow resistance. The present invention pertains to a filter obtained by laminating woven fabrics or knitted fabrics, the filter being characterized in that: said woven fabrics or knitted fabrics comprise a fiber capable of adsorbing components dissolved in liquid: said fiber has a diameter of 100-600 m; the woven fabrics or knitted fabrics have a porosity of 15-70%; and variation in area porosity in the thickness direction of the laminate is 15% or less.

The present invention provides a filter which, even when raw water is subjected to high-speed treatment, enables achieving a high solute rejection ratio and a long solute filtration life and which exhibits a low water flow resistance. The present invention pertains to a filter obtained by laminating woven fabrics or knitted fabrics, the filter being characterized in that: said woven fabrics or knitted fabrics comprise a fiber capable of adsorbing components dissolved in liquid: said fiber has a diameter of 100-600 m; the woven fabrics or knitted fabrics have a porosity of 15-70%; and variation in area porosity in the thickness direction of the laminate is 15% or less.

The present invention is directed to a ligated metal-organic framework (MOF) for use in removing both anionic and cationic species from a liquid or liquid stream. The present invention also provides methods for placing the MOF on a substrate to form a MOF-containing product that can be used in the removal of certain species from a given fluid. The MOF may be a Zr-based MOF, such as NU-1000, for removal of certain anions, such as oxy-anions, or having an attached thiosulfonyl-thiol (SO.sub.2SR.sub.2SH, where R.sub.2 is an alkyl group) ligand for complexation with certain cationic species in addition to the anions. The substrate may be any substrate to which a given MOF may be attached, including inert polypropylene polymer resin beads, a macroscopic fabric such as a mesh material or mesh filter, and a molecular fabric.

The present invention is directed to a ligated metal-organic framework (MOF) for use in removing both anionic and cationic species from a liquid or liquid stream. The present invention also provides methods for placing the MOF on a substrate to form a MOF-containing product that can be used in the removal of certain species from a given fluid. The MOF may be a Zr-based MOF, such as NU-1000, for removal of certain anions, such as oxy-anions, or having an attached thiosulfonyl-thiol (SO.sub.2SR.sub.2SH, where R.sub.2 is an alkyl group) ligand for complexation with certain cationic species in addition to the anions. The substrate may be any substrate to which a given MOF may be attached, including inert polypropylene polymer resin beads, a macroscopic fabric such as a mesh material or mesh filter, and a molecular fabric.

The present invention provides a filter which, even when raw water is subjected to high-speed treatment, enables achieving a high solute rejection ratio and a long solute filtration life and which exhibits a low water flow resistance. The present invention pertains to a filter obtained by laminating woven fabrics or knitted fabrics, the filter being characterized in that: said woven fabrics or knitted fabrics comprise a fiber capable of adsorbing components dissolved in liquid: said fiber has a diameter of 100-600 m; the woven fabrics or knitted fabrics have a porosity of 15-70%; and variation in area porosity in the thickness direction of the laminate is 15% or less.

The present invention provides a filter which, even when raw water is subjected to high-speed treatment, enables achieving a high solute rejection ratio and a long solute filtration life and which exhibits a low water flow resistance. The present invention pertains to a filter obtained by laminating woven fabrics or knitted fabrics, the filter being characterized in that: said woven fabrics or knitted fabrics comprise a fiber capable of adsorbing components dissolved in liquid: said fiber has a diameter of 100-600 m; the woven fabrics or knitted fabrics have a porosity of 15-70%; and variation in area porosity in the thickness direction of the laminate is 15% or less.

The present invention relates to a method for producing purified water comprising a step (a) of passing water through a mixed bed ion exchanger comprising beads having a diameter between 0.2 and 0.7 mm and a step (b) of passing water through a fibrous ion-exchange material. The invention further relates to a module comprising the mixed bed ion exchange resin and the fibrous material and to a water treatment system for producing ultrapure water comprising the mixed bed ion exchange resin and the fibrous material.