Provided is a method for producing ultrapure water to supply, to a use point, ultrapure water obtained by treating raw material water for ultrapure water production in an ultrapure water production apparatus, wherein the raw material water for ultrapure water production contains at least one or more elements selected from B, As, Al, Ti, Cr, Fe, Cu, Zn, Sn, V, Ga, and Pb, and wherein an ion exchanger-filled module filled with at least a monolithic organic porous anion exchanger is installed in a treatment path of the ultrapure water production apparatus or in a transfer path from the ultrapure water production apparatus to the use point, and water to be treated is passed through the ion exchanger-filled module for treatment.

Provided is a method for producing ultrapure water to supply, to a use point, ultrapure water obtained by treating raw material water for ultrapure water production in an ultrapure water production apparatus, wherein the raw material water for ultrapure water production contains at least one or more elements selected from B, As, Al, Ti, Cr, Fe, Cu, Zn, Sn, V, Ga, and Pb, and wherein an ion exchanger-filled module filled with at least a monolithic organic porous anion exchanger is installed in a treatment path of the ultrapure water production apparatus or in a transfer path from the ultrapure water production apparatus to the use point, and water to be treated is passed through the ion exchanger-filled module for treatment.

Provided is a method of regenerating an acrylic resin (B2), comprising (A) providing a collection of particles of acrylic resin (B2) that has calculated Hansch parameter of 1.0 to 2.5, wherein one or more humic acid, one or more fulvic acid, or a mixture thereof, is adsorbed onto said acrylic resin (B2), and (B) bringing said collection of particles of acrylic resin (B2) into contact with an aqueous solution (RB) having pH of 10 or higher, to form a mixture B2RB, (C) then separating acrylic resin (B4) from said mixture B2RB.

A purification method for an aqueous hydrogen peroxide solution, includes passing the aqueous hydrogen peroxide solution through a first H-form strong cation exchange resin column 1, a salt-form strong anion exchange resin column 2 and a second H-form strong cation exchange resin column 3. An H-form strong cation exchange resin having crosslinking of 6% or less, an H-form strong cation exchange resin having crosslinking of 9% or more, or an H-form strong cation exchange resin produced by steps (a) and (b) is used as an H-form strong cation exchange resin packed in the second H-form strong cation exchange resin column 3: (a) copolymerizing a monovinyl aromatic monomer with a crosslinkable aromatic monomer having a non-polymerizable impurity content of 3% by weight or less therein using a predetermined amount of a specified radical polymerization initiator at a predetermined polymerization temperature to obtain a crosslinked copolymer; and (b) sulfonating the crosslinked copolymer.

A purification method for an aqueous hydrogen peroxide solution, includes passing the aqueous hydrogen peroxide solution through a first H-form strong cation exchange resin column 1, a salt-form strong anion exchange resin column 2 and a second H-form strong cation exchange resin column 3. An H-form strong cation exchange resin having crosslinking of 6% or less, an H-form strong cation exchange resin having crosslinking of 9% or more, or an H-form strong cation exchange resin produced by steps (a) and (b) is used as an H-form strong cation exchange resin packed in the second H-form strong cation exchange resin column 3: (a) copolymerizing a monovinyl aromatic monomer with a crosslinkable aromatic monomer having a non-polymerizable impurity content of 3% by weight or less therein using a predetermined amount of a specified radical polymerization initiator at a predetermined polymerization temperature to obtain a crosslinked copolymer; and (b) sulfonating the crosslinked copolymer.

A continuous resin regeneration system includes a process by which resin in need of being recharged is continuously cycled out of a filtration column as new resin is flowed in. Downstream filtration columns also undergo this cycling but at slower and related rates as the first column with the dirtiest water will naturally degrade resin faster than the downstream columns. Contaminated water is cleaned by the continuously cycled resin in multiple columns. The degree of cleaning of earlier filtration columns affects the resin flow rate of later filtration columns.

A continuous resin regeneration system includes a process by which resin in need of being recharged is continuously cycled out of a filtration column as new resin is flowed in. Downstream filtration columns also undergo this cycling but at slower and related rates as the first column with the dirtiest water will naturally degrade resin faster than the downstream columns. Contaminated water is cleaned by the continuously cycled resin in multiple columns. The degree of cleaning of earlier filtration columns affects the resin flow rate of later filtration columns.

An ion exchange device is used that includes an anion exchange tank, a cation exchange tank and a tower body side portion, in which the anion exchange tank and the cation exchange tank are allowed to communicate by communication means that is arranged around the outside of the anion exchange tank and the cation exchange tank. The ion exchange device also includes supply/discharge pipes for supplying or discharging a liquid to or from an upper portion and a lower portion of the anion exchange tank, and supply/discharge pipes for supplying or discharging a liquid to or from an upper portion and a lower portion of the cation exchange tank. A water collection/distribution member that allows water to pass but prevents passage of an ion-exchange resin is provided in a flat plate.

An ion exchange device is used that includes an anion exchange tank, a cation exchange tank and a tower body side portion, in which the anion exchange tank and the cation exchange tank are allowed to communicate by communication means that is arranged around the outside of the anion exchange tank and the cation exchange tank. The ion exchange device also includes supply/discharge pipes for supplying or discharging a liquid to or from an upper portion and a lower portion of the anion exchange tank, and supply/discharge pipes for supplying or discharging a liquid to or from an upper portion and a lower portion of the cation exchange tank. A water collection/distribution member that allows water to pass but prevents passage of an ion-exchange resin is provided in a flat plate.

Provided is a method of regenerating an acrylic resin (B2), comprising (A) providing a collection of particles of acrylic resin (B2) that has calculated Hansch parameter of 1.0 to 2.5, wherein one or more humic acid, one or more fulvic acid, or a mixture thereof, is adsorbed onto said acrylic resin (B2), and (B) bringing said collection of particles of acrylic resin (B2) into contact with an aqueous solution (RA) having pH of 4 or lower, to form a mixture B2RA, (C) then separating acrylic resin (B3) from said mixture B2RA.