A deionization device for liquids includes a first chamber for a first ion exchange agent that has a first intake opening and a first discharge opening. A second chamber for a second ion exchange agent has a second intake opening and a second discharge opening. A line connects the first chamber and the second chamber that has a third intake opening and a third discharge opening. The third intake opening is dedicated to the first discharge opening of the first chamber and the third discharge opening is dedicated to the second intake opening of the second chamber. The line also has a first regeneration opening for a first regeneration liquid, wherein the first regeneration opening can be closed for deionization, and wherein the line can be closed for regenerating the deionization device such that the third intake opening can be isolated from the third discharge opening.

A deionization device for liquids includes a first chamber for a first ion exchange agent that has a first intake opening and a first discharge opening. A second chamber for a second ion exchange agent has a second intake opening and a second discharge opening. A line connects the first chamber and the second chamber that has a third intake opening and a third discharge opening. The third intake opening is dedicated to the first discharge opening of the first chamber and the third discharge opening is dedicated to the second intake opening of the second chamber. The line also has a first regeneration opening for a first regeneration liquid, wherein the first regeneration opening can be closed for deionization, and wherein the line can be closed for regenerating the deionization device such that the third intake opening can be isolated from the third discharge opening.

The present invention makes it possible to provide a high-purity carboxylic acid ester in which the Ag, Al, Au, Ca, Cr, Cu, Fe, K, Mg, Na, Sn, and Zn contents as metal impurity contents are each less than 1 ppb and the anionic impurity content is less than 1 ppm. The present invention also makes it possible to provide a method for producing a high-purity carboxylic acid ester, the method including a step for bringing a crude carboxylic acid ester that contains anionic impurities and Ag, Al, Au, Ca, Cr, Cu, Fe, K, Mg, Na, Sn, and Zn as metal impurities into contact with a cation-exchange resin (II), followed by a step for bringing the crude carboxylic acid ester into contact with an anion-exchange resin (III).

A purification method for spent fuel pool water from nuclear power generation, the method comprising: passing the water at a linear flow velocity of 50 m/h or less through a purification apparatus for the water comprising an ion exchange resin layer and a metal-doped resin layer which is laid at a bed height of 2 cm or more on a surface layer of the ion exchange resin layer wherein the water to be treated is contacted with the metal-doped resin layer to decompose a pro-oxidant contained in the water; and subsequently contacting the water with the ion exchange resin.

A purification method for spent fuel pool water from nuclear power generation, the method comprising: passing the water at a linear flow velocity of 50 m/h or less through a purification apparatus for the water comprising an ion exchange resin layer and a metal-doped resin layer which is laid at a bed height of 2 cm or more on a surface layer of the ion exchange resin layer wherein the water to be treated is contacted with the metal-doped resin layer to decompose a pro-oxidant contained in the water; and subsequently contacting the water with the ion exchange resin.

Provided is a method of purifying water comprising (a) providing an aqueous solution (A) that has pH of 5.5 or lower and that comprises (i) one or more dissolved organic compounds in an amount of 5 mg/L or more, measured as dissolved organic carbon, and (ii) 95% or more water by weight based on the weight of the aqueous solution (A), and (b) bringing the aqueous solution (A) into contact with a collection of particles of acrylic resin (B) that has calculated Hansch parameter of 1.0 to 2.5, and (c) then separating an aqueous solution (C) from the collection of particles of acrylic resin (B).

Provided is a method of purifying water comprising (a) providing an aqueous solution (A) that has pH of 5.5 or lower and that comprises (i) one or more dissolved organic compounds in an amount of 5 mg/L or more, measured as dissolved organic carbon, and (ii) 95% or more water by weight based on the weight of the aqueous solution (A), and (b) bringing the aqueous solution (A) into contact with a collection of particles of acrylic resin (B) that has calculated Hansch parameter of 1.0 to 2.5, and (c) then separating an aqueous solution (C) from the collection of particles of acrylic resin (B).

A method for purifying an organic solvent has a first treatment of bringing an organic solvent to be treated into contact with an H-type cation exchanger, and a second treatment of bringing a treated liquid from the first treatment into contact with an anion exchanger and an H-type strongly acidic cation exchanger. According to the present application, the provided method and an apparatus for purifying an organic solvent remove metal impurities of both metal species of monovalent and polyvalent metals in the organic solvent.

A method for purifying an organic solvent has a first treatment of bringing an organic solvent to be treated into contact with an H-type cation exchanger, and a second treatment of bringing a treated liquid from the first treatment into contact with an anion exchanger and an H-type strongly acidic cation exchanger. According to the present application, the provided method and an apparatus for purifying an organic solvent remove metal impurities of both metal species of monovalent and polyvalent metals in the organic solvent.

Water softening device includes water softening tank, neutralization tank, and electrolytic tank. Electrolytic tank generates acidic electrolytic water for regenerating weakly acidic cation exchange resin and alkaline electrolytic water for regenerating weakly basic anion exchange resin. Then, water softening device includes an acidic electrolytic water circulation flow path that circulates the acidic electrolytic water through electrolytic tank, first discharge port, water softening tank, and first water intake port in the stated order, and an alkaline electrolytic water circulation flow path that circulates the alkaline electrolytic water through electrolytic tank, second discharge port, neutralization tank, and second water intake port in the stated order.