Abstract: The present invention relates to a separation membrane module including: a pressure vessel; a plurality of separation membrane elements which are provided in the pressure vessel and each includes: a wound membrane body in which a separation membrane, a liquid-to-be-treated channel member and a permeated liquid channel member are spirally wound around a permeated liquid collection tube; and anti-telescoping plates disposed on both ends of the wound membrane body; and a thrust load holding member which holds a thrust load generated when water passes through the separation membrane elements, in which a thrust load adjustment holding member which is capable of adjusting the thrust load by adjusting a total length of the separation membrane elements in the pressure vessel, is provided on at least one end of the thrust load holding member in an axial direction of the separation membrane elements.

Abstract: The present invention relates to a fresh water generation method using a water treatment apparatus, the method including feeding water to be treated into a membrane element including a reverse osmosis membrane or a nanofiltration membrane to separate into concentrate and permeate, in which the method includes, under operation of the apparatus, adjusting a concentrate flow rate and/or a permeate flow rate based on a water quality index of the water to be treated and a water quality index of combined water prepared by combining the concentrate and the permeate at a ratio based on a predetermined permeate recovery rate, so that the water quality index of the water to be treated falls within a tolerance on the water quality index of the combined water.

Abstract: The present invention relates to a separation membrane module including: a pressure vessel; a plurality of separation membrane elements which are provided in the pressure vessel and each includes: a wound membrane body in which a separation membrane, a liquid-to-be-treated channel member and a permeated liquid channel member are spirally wound around a permeated liquid collection tube; and anti-telescoping plates disposed on both ends of the wound membrane body; and a thrust load holding member which holds a thrust load generated when water passes through the separation membrane elements, in which a thrust load adjustment holding member which is capable of adjusting the thrust load by adjusting a total length of the separation membrane elements in the pressure vessel, is provided on at least one end of the thrust load holding member in an axial direction of the separation membrane elements.

Abstract: The present invention relates to a fresh water generation method using a water treatment apparatus, the method including feeding water to be treated into a membrane element including a reverse osmosis membrane or a nanofiltration membrane to separate into concentrate and permeate, in which the method includes, under operation of the apparatus, adjusting a concentrate flow rate and/or a permeate flow rate based on a water quality index of the water to be treated and a water quality index of combined water prepared by combining the concentrate and the permeate at a ratio based on a predetermined permeate recovery rate, so that the water quality index of the water to be treated falls within a tolerance on the water quality index of the combined water.