| 摘要 |
PROBLEM TO BE SOLVED: To provide a cleaning method of a filter membrane which carries out an effective cleaning and maintains a high filtering flow flux when filtering with the filter membrane using, as a raw water, river water, lake water, ground water, storage water, sewage secondary treatment effluent, industrial wastewater, sewage, etc. or when filtering with the filter membrane to separate or concentrate a valuable substance. SOLUTION: The cleaning method of the filter membrane, in a cleaning step of a casing receiving type membrane module or a dipping type membrane module, is characterized by cleaning by combination of a gas cleaning step A wherein a suspended matter is removed from the filter membrane by making a gas-cleaning medium to be injected to a water side to be treated of the filter membrane forming the membrane module to contact with the whole filter membrane, and a gas cleaning step B wherein the suspended matter is removed from the filter membrane by making a liquid level to lower once by filtering and discharging of the water to be treated in the membrane module, lowering the liquid level of the water to be treated around the filter membrane, and thereafter carrying out gas cleaning while raising the liquid level of the water side to be treated upwards from the lower part of the filter membrane. COPYRIGHT: (C)2007,JPO&INPIT
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