Abstract: A chelate complex is removed from a chemical which is used in a semiconductor production process and contains a compound having a chelating ability, and the cleaning load is also reduced. Specifically disclosed is a method for purifying a chemical which is used in a semiconductor production process and contains a compound having a chelating ability, wherein a chelate complex which is formed from impurity metals such as nickel and copper contained in an alkaline chemical is removed from the chemical by treating the alkaline chemical with an organic complex adsorbing material.

Abstract: Foreign substances which are not inherently contained in a polishing slurry are selectively separated and removed from a polishing slurry component comprised of abrasives, a solvent and an additive which are inherently contained in the polishing slurry.

Abstract: Filter media for liquid purification, which can remove metal compounds or metal ions containing in polishing or washing liquids such as alkali, acid solution or ultra-pure water used for silicon wafers of semiconductors. Removal of metals from various kind of liquid such as inorganic chemicals, organic solvent, or industrial waste water are also the subject of the present invention. The Filter media made of melt-blown nonwoven substrate comprising of aethylene/norbornene copolymer represented by the following formula [1] and/or a polycyclic norbornene polymer represented by the following formulae [2](a),(b),(c) as raw material, wherein said ethylene/norbornene copolymer and said polycyclic norbornene polymer have a glass transition temperature (Tg) selected in a range from 80 to 180° C. and melt volume rate (MVR) (ISO 1133, measuring conditions: 260° C., 2.

Abstract: Foreign substances which are not inherently contained in a polishing slurry are selectively separated and removed from a polishing slurry component comprised of abrasives, a solvent and an additive which are inherently contained in the polishing slurry.

Abstract: A method for quantitative determination of nickel and/or copper, by which an ultratrace amount of nickel and/or copper contained in a liquid sample can be easily and simply determined in situ; and apparatus to be used in the method. The method comprises a step of adding a complex-forming agent capable of forming a complex with nickel and copper to a liquid sample containing nickel and/or copper in unknown concentrations to form colored fine particles of a nickel complex and/or a copper complex and a step of determining the quantities of nickel and/or copper on the basis of the colored fine particles.

Abstract: A chelate complex is removed from a chemical which is used in a semiconductor production process and contains a compound having a chelating ability, and the cleaning load is also reduced. Specifically disclosed is a method for purifying a chemical which is used in a semiconductor production process and contains a compound having a chelating ability, wherein a chelate complex which is formed from impurity metals such as nickel and copper contained in an alkaline chemical is removed from the chemical by treating the alkaline chemical with an organic complex adsorbing material.

Abstract: A material for purification of a semiconductor polishing slurry that without changing of pH value, is capable of efficiently purifying a polishing slurry to thereby not only prevent metal contamination of a polished object as effectively as possible but also achieve recycling of a polishing slurry without any problem; a relevant module for purification of a semiconductor polishing slurry; and a process for purifying a semiconductor polishing slurry with the use thereof. In particular, a material for purification of a semiconductor polishing slurry characterized in that it comprises a fibrous substrate having a functional group capable of forming a metal chelate or such a functional group together with hydroxyl fixed onto at least the surface thereof. This material for purification of a semiconductor polishing slurry is, for example, used in such a manner that it is inserted in a container fitted with polishing slurry inflow port and outflow port while ensuring passage of polishing slurry flow.

Abstract: A material for purification of a semiconductor polishing slurry that without changing of pH value, is capable of efficiently purifying a polishing slurry to thereby not only prevent metal contamination of a polished object as effectively as possible but also achieve recycling of a polishing slurry without any problem; a relevant module for purification of a semiconductor polishing slurry; and a process for purifying a semiconductor polishing slurry with the use thereof. In particular, a material for purification of a semiconductor polishing slurry characterized in that it comprises a fibrous substrate having a functional group capable of forming a metal chelate or such a functional group together with hydroxyl fixed onto at least the surface thereof. This material for purification of a semiconductor polishing slurry is, for example, used in such a manner that it is inserted in a container fitted with polishing slurry inflow port and outflow port while ensuring passage of polishing slurry flow.

Abstract: A system for producing ultra-pure water having an electrodialysis unit 1, which has a membrane selectively permeable to monovalent cations and a membrane selectively permeable to monovalent anions, and a reverse osmosis unit 5 which is connected after the electrodialysis unit 1 in series.

Abstract: An apparatus for the treatment of a low-concentration organic waste water for relaim a low-concentration organic waste water having a TOC concentration of from 0.5 to 3 ppm and obtaining an ultra pure water having a TOC concentration of not more than 1 ppb is characterized by the fact that a first treating system comprising a reverse osmosis unit for transforming a low-concentration organic waste water having a TOC concentration of from 0.5 to 3 ppm into a low-concentration organic waste water having a TOC concentration of from 60 to 200 ppb and a vacuum degasifier adapted to admit an inert gas at a volumetric feed flow rate in the range of from 0.001 to 1.0 based on the volume of the waste water under treatment at a vacuum rate of not more than 35 Torrs and a second treating system comprising a low-pressure ultraviolet decomposition unit for emitting an ultraviolet light of a wavelength of 184.