Abstract: The present invention provides a cation exchange membrane which has excellent durability, a high limiting current density, a low direct current membrane resistance and excellent selectivity to monovalent cations. In the present invention, a cation exchange membrane excellent in selective permeability to monovalent cations is produced by bringing high molecular cations into contact with a surface of a cation exchange membrane in the presence of anions of an oxyacid or anions of an organic sulfonic acid.

Abstract: The present invention provides a cation exchange membrane which has excellent durability, a high limiting current density, a low direct current membrane resistance and excellent selectivity to monovalent cations. In the present invention, a cation exchange membrane excellent in selective permeability to monovalent cations is produced by bringing high molecular cations into contact with a surface of a cation exchange membrane in the presence of anions of an oxyacid or anions of an organic sulfonic acid.

Abstract: The packaging case comprises, when assembled, a back part (aback hanging board), a bottom part (a bottom cover), a front part (a front cover, a front hanging board), the boards and covers being formed continuously in this order and bordered by fold lines, and a side part (a side cover, a glue margin) continuously extending from each side edge of the front cover except the neighborhood of the front hanging board and bordered by fold lines. A window is formed in the front cover, and a hook hole is respectively punched in the front and the back hanging boards to make a single matching hook hole. In one side edge of the back hanging board, a U-shaped perforated tear portion is provided for tearing off a part of the side edge glued to a corresponding glue margin.

Abstract: A process for treating effluent from a flue-gas desulfurization system wherein the resulting gypsum is removed, comprises filtering the gypsum and fly ash free effluent by a filter, transferring the filtrate to an electrodialyzer wherein cation-exchange membranes and univalent anion-exchange membranes are alternately set up, concentrating chlorine ions in the solution therein by dialysis, further concentrating the solution by evaporation in an evaporator, kneading the concentrated solution with cement or a mixture of cement and coal ash to a solid matter with no harm, and thereafter abandoning for landfill; and an apparatus for treating effluent from a flue-gas desulfurization system, comprising a filter for filtering the effluent to a turbidity low enough for treatment by an electrodialyzer wherein the effluent is to be separated into concentrated and dilute solutions, the electrodialyzer equipped with an alternate arrangement of cation- and anion-exchange membranes, with concentration and dilution compartme

Abstract: An apparatus for recovering an acid from an acid-containing waste liquor, which is a diffusion dialytic cell having a plurality of anion exchange membranes disposed to alternately form feed liquor compartments to which the acid-containing waste liquor is supplied and recovery compartments to which water is supplied, wherein a cooling compartment defined by a water-impermeable membrane is provided adjacent to such feed liquor compartments or recovery compartments.

Abstract: A method for recovering sulfuric acid from a titanium sulfate waste liquor by diffusion dialysis in a diffusion dialytic cell provided with anion exchange membranes, which comprises subjecting the titanium sulfate waste liquor to precision filtration to remove a solid content having a particle size of at least 0.1 .mu.m to a level of not more than 100 .mu.g/l, and placing the filtered liquor to face water with an anion exchange membrane interposed therebetween so that sulfuric acid in the titanium sulfate waste liquor is recovered by diffusion dialysis.

Abstract: A container for granular substances, having a mouth which opens diagonally and upwardly into a triangular shape at an upper part of a left side board. The mouth comprises a pasting piece, which is slightly higher than a front board and a rear board and a sliding board, consisting of an arcuate part and a flap piece contiguous to the circumference of the arcuate part. The sliding board is supported and slides between the inner surface of the front board and the outer surface of a tongue piece formed at the front board. The circumferential edge of the arcuate part always projects above a ceiling board, whether the mouth is opened or closed. The container ensures perfect sealing of granular substances contained therein while the mouth is closed.