Provided is a method for analyzing the metal impurity content that includes passing water to be analyzed through a monolithic organic porous anion exchanger, thereby allowing the monolithic organic porous anion exchanger to capture metal impurities in the water to be analyzed; passing an eluent through the monolithic organic porous anion exchanger which has been allowed to capture metal impurities in the water to be analyzed, to collect an effluent, thereby obtaining a collected eluent containing metal impurities in the water to be analyzed eluted from the monolithic organic porous anion exchanger; and measuring the content of each metal impurity in the collected eluent.

Provided is a method for analyzing the metal impurity content that includes passing water to be analyzed through a monolithic organic porous anion exchanger, thereby allowing the monolithic organic porous anion exchanger to capture metal impurities in the water to be analyzed; passing an eluent through the monolithic organic porous anion exchanger which has been allowed to capture metal impurities in the water to be analyzed, to collect an effluent, thereby obtaining a collected eluent containing metal impurities in the water to be analyzed eluted from the monolithic organic porous anion exchanger; and measuring the content of each metal impurity in the collected eluent.

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.

A continuous resin regeneration system includes a process by which resin in need of being recharged is continuously recharged and cleaned with a plurality of two-set filtration columns so that resin regeneration and the flow of influent is continuous and interrupted. 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 influent is cleaned by the continuously recharged resin in multiple column sets. 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 recharged and cleaned with a plurality of two-set filtration columns so that resin regeneration and the flow of influent is continuous and interrupted. 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 influent is cleaned by the continuously recharged resin in multiple column sets. The degree of cleaning of earlier filtration columns affects the resin flow rate of later filtration columns.

Methods for removing an oxyanion from an aqueous source containing said oxyanion, comprising contacting said aqueous source with an aqueous-insoluble hydrophobic solution containing an oxyanion extractant compound dissolved in an aqueous-insoluble hydrophobic solvent to result in formation of an oxyanion salt of said extractant compound and extraction of said oxyanion salt into said aqueous-insoluble hydrophobic solution, wherein said extraction results in an extraction affinity (D) of said oxyanion of at least 1, wherein D is the concentration ratio of said oxyanion in the organic phase divided by the concentration of said oxyanion in the aqueous phase; wherein said extractant compound has the following composition: ##STR00001##
wherein at least one of R.sup.1-R.sup.10 is or contains a hydrocarbon (R) group containing at least 4, 5, 6, 7, 8, 9, 10, 11, or 12 carbon atoms.

A reclaiming method is disclosed including conducting evaporation by introducing a part of the absorbent to recover CO.sub.2 or H.sub.2S in a gas in a closed system recovery unit and separating a degraded substance contained in the absorbent from the absorbent to be introduced into an evaporator and obtain recovery steam containing an absorbent and CO.sub.2 or H.sub.2S by a heating section that is provided on a circulation line that circulates in the evaporator; and removing ionic degraded substance by cooling the concentrate obtained in the evaporation and removing an ionic degraded substance in the concentrate after the cooling, wherein a purified concentrate from which the ionic degraded substance has been removed is reused as a purified absorbent.

A reclaiming method is disclosed including conducting evaporation by introducing a part of the absorbent to recover CO.sub.2 or H.sub.2S in a gas in a closed system recovery unit and separating a degraded substance contained in the absorbent from the absorbent to be introduced into an evaporator and obtain recovery steam containing an absorbent and CO.sub.2 or H.sub.2S by a heating section that is provided on a circulation line that circulates in the evaporator; and removing ionic degraded substance by cooling the concentrate obtained in the evaporation and removing an ionic degraded substance in the concentrate after the cooling, wherein a purified concentrate from which the ionic degraded substance has been removed is reused as a purified absorbent.

A method for recovering water from purified terephthalic acid production wastewater includes: producing purified terephthalic acid comprising purified terephthalic acid feedstock and wastewater comprising impurities; separating the purified terephthalic acid feedstock from the wastewater comprising impurities; transferring the wastewater to a tank; adjusting the p H of the wastewater with a basic solution; adjusting the temperature of the wastewater; passing the wastewater to a column; contacting the wastewater with an ion exchange resin to remove the impurities; and recovering the water depleted of impurities.