Abstract: A method for operating a separation membrane module including identifying a clogged portion of the separation membrane module based on a resistance of a lower portion of the separation membrane module, a filtration resistance of a separation membrane portion, and a resistance of an upper portion of the separation membrane module, in a water production system for obtaining treated water by filtering water-to-be-treated with the separation membrane module.

Abstract: The present invention relates to a method of controlling a fresh-water production apparatus for treating a raw water in stages by N-stage (N is a natural number of 2 or larger) water treatment methods, the method including: a filtration-characteristic prediction step; a filtration-characteristic deviation assessment step; a filtration-characteristic deviation assessment step; a cyclic prediction calculation step; a control condition recording step; a cyclic prediction calculation step; and a control condition recording step, in which the fresh-water production apparatus is controlled on the basis of the control condition recording step for the (n?1)-th stage water treatment method and the control condition recording step for the n-th stage water treatment method.

Abstract: The present invention provides a fresh water generator operating method and a determination program that are employed in a method for cleaning a separation membrane module following membrane filtration, and that, while various cleaning steps such as reverse pressure cleaning, air cleaning, chemical solution cleaning are taking place after completion of the membrane filtration, determines cleaning troubles by calculating a temporal change in resistance increase rate on the basis of an increase in membrane differential pressure.

Abstract: The present invention relates to a computer-readable recording medium having recorded thereon a clogging location determination program for a separation membrane module, in which, in order to determine a clogging location of a separation membrane module in a fresh water generation system for obtaining treated water by filtrating water to be treated by a separation membrane module having a separation membrane, a computer is caused to function as a clogging location determination means for determining a clogging location of the separation membrane module from a resistance in a lower part of the separation membrane module, a filtration resistance of a hollow-fiber membrane, and a resistance in an upper part of the separation membrane module.

Abstract: The present invention relates to a computer-readable recording medium having recorded thereon a clogging location determination program for a separation membrane module, in which, in order to determine a clogging location of a separation membrane module in a fresh water generation system for obtaining treated water by filtrating water to be treated by a separation membrane module having a separation membrane, a computer is caused to function as a clogging location determination means for determining a clogging location of the separation membrane module from a resistance in a lower part of the separation membrane module, a filtration resistance of a hollow-fiber membrane, and a resistance in an upper part of the separation membrane module.

Abstract: The present invention relates to a computer-readable recording medium having recorded thereon a clogging location determination program for a separation membrane module, in which, in order to determine a clogging location of a separation membrane module in a fresh water generation system for obtaining treated water by filtrating water to be treated by a separation membrane module having a separation membrane, a computer is caused to function as a clogging location determination means for determining a clogging location of the separation membrane module from a resistance in a lower part of the separation membrane module, a filtration resistance of a hollow-fiber membrane, and a resistance in an upper part of the separation membrane module.

Abstract: An efficient method is provided for cleaning hollow fiber membrane modules, the method being capable of efficiently removing substances accumulated inside hollow fiber membrane modules. The internal liquid on the raw liquid side of the hollow fiber membrane module (3) is discharged from a lower end face nozzle (19) of the hollow fiber membrane module (3) while air-cleaning is performed. The method for cleaning hollow fiber membrane modules is characterized in that the rate of liquid discharge from the lower end face nozzle of the hollow fiber membrane module (3) when discharging the internal liquid from the lower end face nozzle is adjusted so that the air supplied from the lower end face nozzle of the hollow fiber membrane module (3) through the aeration holes is supplied to the hollow fiber membrane module (3).

Abstract: An efficient method is provided for cleaning hollow fiber membrane modules, the method being capable of efficiently removing substances accumulated inside hollow fiber membrane modules. The internal liquid on the raw liquid side of the hollow fiber membrane module (3) is discharged from a lower end face nozzle (19) of the hollow fiber membrane module (3) while air-cleaning is performed. The method for cleaning hollow fiber membrane modules is characterized in that the rate of liquid discharge from the lower end face nozzle of the hollow fiber membrane module (3) when discharging the internal liquid from the lower end face nozzle is adjusted so that the air supplied from the lower end face nozzle of the hollow fiber membrane module (3) through the aeration holes is supplied to the hollow fiber membrane module (3).