Method for operating separation membrane module, computer-readable recording medium having program recorded thereon, and water production system

A method for operating a separation membrane module to identify 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,

• wherein
• the separation membrane module comprises a cylindrical case in which a separation membrane is inserted, and the separation membrane module has:
• an-a water-to-be-treated supply part supplying the water-to-be-treated in a lower portion on a primary side;
• a treated water discharge part discharging the treated water in an upper portion on a secondary side;
• and a backwashing wastewater discharge part discharging backwashing wastewater communicating with an outer side of the separation membrane in an upper portion of a side surface of the cylindrical case on the primary side, and
• the water production system comprises a supply pressure sensor measuring a pressure (P1) of the water-to-be-treated supply part, a secondary side pressure sensor measuring a pressure (P2) of the treated water discharge part, and a primary side outlet pressure sensor measuring a pressure (P3) of the backwashing wastewater discharge part,
• the method comprising:
• calculating a pressure difference (ΔP1) between the P1 and the P3 in a filtration process of filtering the water-to-be-treated from the primary side to the secondary side of the separation membrane module as a first resistance R1,
• a pressure difference (ΔP2) between the P3 and the P2 in the filtration process as a second resistance R2, and
• a pressure difference (ΔP3) between the P1 and the P3 in a backwashing process of pressure-feeding from the secondary side to the primary side of the separation membrane module as a third resistance R3, and
• identifying the clogged portion of the separation membrane module based on amounts of change or rates of change from respective initial values of the first resistance R1, the second resistance R2, and the third resistance R3 that are obtained by the calculation.