Abstract: A water treatment method treats raw water (water to be treated) containing organic wastewater. The method includes (i) an aeration process performs an initial absorption treatment by aerating the water to be treated, (ii) a filtration process for filtering the water to be treated which has been treated by the initial absorption treatment in the aeration process, (iii) a digestion treatment process for digesting solids captured by the filtration process, (iv) a biological treatment process for denitrifying, with activated sludge, filtered water obtained through the filtration process, (v) a sludge transfer process for sending the activated sludge from the biological treatment process to the aeration process, and (vi) an adjustment process for adjusting an amount of the activated sludge sent to the aeration process via the sludge transfer process based on a nitrogen concentration of treated water which has been biologically treated by the biological treatment process.

Abstract: A membrane element 36 includes filtration membranes 45 on the flat part of the membrane element 36. Spacing members 60 keep spacing S between the filtration membranes 45 between the membrane elements 36 when the membrane elements 36 are arranged with the filtration membranes 45 opposed to each other. The spacing members 60 each have spacer sections 61a and 61b that keep the spacing S between the filtration membranes 45 between the membrane elements 36 in the direction of a membrane surface cleaning stream that flows along the surface of the filtration membrane 45.

Abstract: A membrane element 36 includes filtration membranes 45 on the flat part of the membrane element 36. Spacing members 60 keep spacing S between the filtration membranes 45 between the membrane elements 36 when the membrane elements 36 are arranged with the filtration membranes 45 opposed to each other. The spacing members 60 each have spacer sections 61a and 61b that keep the spacing S between the filtration membranes 45 between the membrane elements 36 in the direction of a membrane surface cleaning stream that flows along the surface of the filtration membrane 45.

Abstract: A vinyl•cis-polybutadiene rubber is provided containing 1,2-polybutadiene and a polymer substance of a melting point lower than that of the 1,2-polybutadiene and with at least one unsaturated double bond per repeating unit, where the 1,2-polybutadiene and the polymer substance are dispersed at physically and/or chemically adsorbed states in the cis-polybutadiene rubber as the matrix component of the vinyl•cis-polybutadiene rubber, and a method for producing the same, to provide a vulcanized product exerting a small die swell ratio and excellent extrusion processability and operability, as well as very great characteristics demanded for the side tread of tire and the like.

Abstract: A vinyl.cis-polybutadiene rubber is provided containing 1,2-polybutadiene and a polymer substance of a melting point lower than that of the 1,2-polybutadiene and with at least one unsaturated double bond per repeating unit, where the 1,2-polybutadiene and the polymer substance are dispersed at physically and/or chemically adsorbed states in the cis-polybutadiene rubber as the matrix component of the vinyl.cis-polybutadiene rubber, and a method for producing the same, to provide a vulcanized product exerting a small die swell ratio and excellent extrusion processability and operability, as well as very great characteristics demanded for the side tread of tire and the like.

Abstract: A vinyl.cis-polybutadiene rubber is provided containing 1,2-polybutadiene and a polymer substance of a melting point lower than that of the 1,2-polybutadiene and with at least one unsaturated double bond per repeating unit, where the 1,2-polybutadiene and the polymer substance are dispersed at physically and/or chemically adsorbed states in the cis-polybutadiene rubber as the matrix component of the vinyl.cis-polybutadiene rubber, and a method for producing the same, to provide a vulcanized product exerting a small die swell ratio and excellent extrusion processability and operability, as well as very great characteristics demanded for the side tread of tire and the like.

Abstract: A vinyl.cis-polybutadiene rubber is provided containing 1,2-polybutadiene and a polymer substance of a melting point lower than that of the 1,2-polybutadiene and with at least one unsaturated double bond per repeating unit, where the 1,2-polybutadiene and the polymer substance are dispersed at physically and/or chemically adsorbed states in the cis-polybutadiene rubber as the matrix component of the vinyl.cis-polybutadiene rubber, and a method for producing the same, to provide a vulcanized product exerting a small die swell ratio and excellent extrusion processability and operability, as well as very great characteristics demanded for the side tread of tire and the like.

Abstract: A rubber-modified high impact polystyrene resin composition containing a rubbery polymer, wherein the rubbery polymer is modified polybutadiene which is obtained by modifying high-cis/high-vinyl polybutadiene in the presence of a transition metal catalyst and preferably has a cold flow rate of less than 20 mg/min.

Abstract: Rubber-modified, impact-resistant polystyrene resin compositions having a well balanced combination of improved properties such as tensile strength and tensile elongation as well as reactivity with styrene monomers, impact resistance, low-temperature properties, and gloss, comprise dispersed particles of a rubber polymer which satisfies the following: (1) the content of the rubber polymer in the compositions is from 1 to 25% by weight; (2) the rubber polymer is a high-cis high-vinyl polybutadiene comprising from 65 to 95% cis-1,4-structures and from 30 to 4% 1,2-structures; and (3) the relationship between the 1,4-structures and 1,2-structures of the rubber polymer is represented by the following expression (A), wherein the value of .beta. is in the range of 1.0<.beta..ltoreq.1.43;.beta.=P.sub.1,2-,1-4 /(2.times.P.sub.1,2 .times.P.sub.1,4)(A)wherein P.sub.1,2 represents the content of 1,2-structures, P.sub.1,4 represents the content of 1,4-structures, and P.sub.

Abstract: An improved method for dehydration and concentration of an aqueous solution containing an organic compound is disclosed. The solution is evaporated to produce a gaseous mixture comprising an organic compound vapor and a water vapor. The water vapor is selectively removed from the gaseous mixture by permeation through an aromatic polyimide gas separation membrane while the gaseous mixture being kept in contact with a surface on one side of the gas separation membrane at a temperature of 70.degree. C. or higher to obtain a gaseous mixture comprising the organic compound vapor and a reduced amount of a water vapor.