Extraction of platinum-group elements, e.g. Pd, by adsorption from acidic aqueous solutions, using chelating acrylic fibers having amidoxime substituents followed by recovery by elution with an HCl-thiourea solution. From about 10% to 100% of the acrylic fiber CN are converted to amidoxime by reaction with NH.sub.2OH (hydroxylamine) in H.sub.2O/MeOH solution in the range of 30° C.-90° C. for from 15 min to 72 hrs. The adsorptive loading of elements onto the fiber and the efficiency of elution therefrom is substantially 100%, in multiple cycles of adsorption/elution. The novel fiber/extraction process is rapid, lending it to a continuous recovery operation. A portion of the CN groups of may be converted to carboxylate groups by reaction with NaOH. Short lengths of fiber are loaded into a vertical column and the pregnant solution introduced. Upon breakthrough, the fibers may be eluted, washed and recycled hundreds of times without removal from the column.

A method for recovering an acidic gas, includes: a step of bringing a gas to be treated that contains an acidic gas into gas-liquid into contact with an amine absorbing solution, allowing the amine absorbing solution to absorb the acidic gas, thereby removing the acidic gas from the gas to be treated; a step of allowing the amine absorbing solution that has absorbed the acidic gas to release the acidic gas, thereby regenerating the amine absorbing solution, and at the same time, recovering the released acidic gas; and an analysis step of calculating concentrations of iron ions and/or heavy metal ions in the amine absorbing solution.

A method for recovering an acidic gas, includes: a step of bringing a gas to be treated that contains an acidic gas into gas-liquid into contact with an amine absorbing solution, allowing the amine absorbing solution to absorb the acidic gas, thereby removing the acidic gas from the gas to be treated; a step of allowing the amine absorbing solution that has absorbed the acidic gas to release the acidic gas, thereby regenerating the amine absorbing solution, and at the same time, recovering the released acidic gas; and an analysis step of calculating concentrations of iron ions and/or heavy metal ions in the amine absorbing solution.

To provide a filter capable of efficiently removing metal ions in a treatment liquid, and capable of easily obtaining a solution having an extremely low metal ion content. A depth filter includes a porous molded article. The porous molded article is a sintered material of mixed powder or a swollen material of the sintered material. The mixed powder contains dried gel powder and thermoplastic resin powder. The dried gel powder contains an ion exchange resin including a sulfonic acid group, and a nitrogen-containing chelating resin.

To provide a filter capable of efficiently removing metal ions in a treatment liquid, and capable of easily obtaining a solution having an extremely low metal ion content. A depth filter includes a porous molded article. The porous molded article is a sintered material of mixed powder or a swollen material of the sintered material. The mixed powder contains dried gel powder and thermoplastic resin powder. The dried gel powder contains an ion exchange resin including a sulfonic acid group, and a nitrogen-containing chelating resin.

A solid-phase chelator material usable for the purification of proteins. The solid-phase chelator material comprises a solid phase, polyamine groups bound to the solid phase and chelating groups bound to the polyamine groups. At least a part of the polyamine groups is connected with at least two chelating groups per polyamine group. Each chelating group comprises one or several aminopolycarboxylic acid groups (APA groups), with the proviso that the number of APA groups per polyamine group connected with at least two cheating groups is at least three.

A solid-phase chelator material usable for the purification of proteins. The solid-phase chelator material comprises a solid phase, polyamine groups bound to the solid phase and chelating groups bound to the polyamine groups. At least a part of the polyamine groups is connected with at least two chelating groups per polyamine group. Each chelating group comprises one or several aminopolycarboxylic acid groups (APA groups), with the proviso that the number of APA groups per polyamine group connected with at least two cheating groups is at least three.

A method for conditioning of spent ion exchange resins from nuclear facilities comprises the steps of: mixing the spent ion exchange resins with water to form a reaction mixture; setting and controlling the pH of the reaction mixture in a range from 1.0 to 3.5, preferably in a range from 2.0 to 3.0; adding an oxidant to the reaction mixture, with the temperature of the reaction mixture maintained at 90 ° ° C. or less so that the spent ion exchange resin and the oxidant react with each other to form an aqueous reaction solution comprising the organic reaction products of the spent ion exchange resin; and electrochemically oxidizing the organic reaction products, wherein carbon dioxide is produced and a carbon-depleted aqueous reaction solution having a TOC (total organic carbon) value of less than 50 ppm is obtained. Furthermore, an apparatus for the conditioning of spent ion exchange resins from nuclear facilities is described.

A method for conditioning of spent ion exchange resins from nuclear facilities comprises the steps of: mixing the spent ion exchange resins with water to form a reaction mixture; setting and controlling the pH of the reaction mixture in a range from 1.0 to 3.5, preferably in a range from 2.0 to 3.0; adding an oxidant to the reaction mixture, with the temperature of the reaction mixture maintained at 90 ° ° C. or less so that the spent ion exchange resin and the oxidant react with each other to form an aqueous reaction solution comprising the organic reaction products of the spent ion exchange resin; and electrochemically oxidizing the organic reaction products, wherein carbon dioxide is produced and a carbon-depleted aqueous reaction solution having a TOC (total organic carbon) value of less than 50 ppm is obtained. Furthermore, an apparatus for the conditioning of spent ion exchange resins from nuclear facilities is described.

A process and apparatus for enhanced boron removal from water. The process includes the steps of reacting potassium carbonate or ammonium carbonate with calcium borate in a stream of feed water to form a stream having calcium carbonate and potassium borate salt or ammonium borate salt. The stream having calcium carbonate and potassium borate or ammonium borate is introduced to an ion exchange vessel containing resin having methylglucamine in salt form with potassium carbonate or sodium carbonate to form borate and potassium sulfate or sodium sulfate. The resin in the ion exchange vessel is periodically regenerated.