Computer-readable recording medium on which clogging location specification program for separation membrane module is recorded, water production system, and water production method

A fresh water generation method for obtaining treated water by filtrating water to be treated by a separation membrane module having a separation membrane, comprising the steps of:

• feeding water to be treated to a primary side of the separation membrane module;
• measuring and obtaining a difference in a resistance between an inlet side and an outlet side on the primary side of the separation membrane module in the step of feeding, as being a first resistance R1;
• performing a filtration step by pressure-feeding water to be treated from the primary side to a secondary side of the separation membrane module;
• measuring and obtaining a difference in a resistance between the inlet side on the primary side and the secondary side of the separation membrane module in the filtration step, as being a second resistance R2;
• performing a backwashing step by performing permeation from the secondary side to the primary side of the separation membrane module;
• measuring and obtaining a difference in a resistance between the inlet side and the outlet side on the primary side of the separation membrane module in the backwashing step, as being a third resistance R3;
• 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, comprising the sub-step of:
• determining as to which location is clogged among the lower part of the separation membrane module, the hollow-fiber membrane, and the upper part of the separation membrane module based on computing operations of R1−R3 and R2−(R1−R3) using the first resistance R1, the second resistance R2 and the third resistance R3;
• prioritizing the determined clogging location to be cleaned compared with other locations;
• and
• cleaning the determined clogging location.