To provide a porous membrane which obtains permeation water with extremely high stability without deteriorating the inhibition ratio by large micro pores and without deteriorating the inhibition ratio even if the porous membrane is injured during membrane element preparation or the porous membrane is operated for a long term.
The porous membrane is characterized in that the particulate having the number average particle size of more than 1.2 times to 2.0 times or less of the average pore diameter is attached on the surface of the liquid to be treated of the porous membrane. The preparing method of the porous membrane comprises filtering a particulate dispersion with the number average particle size of more than 1.2 times to 20 times or less of the average pore diameter of the porous membrane from the liquid side to be treated of the porous membrane. The repairing method comprises a step of measuring the average pore diameter of the porous membrane, a step of measuring the maximum pore diameter of the porous membrane and a step of filtering the particulate dispersion with the average particle size of more than 1.2 times of the average pore diameter to the maximum pore diameter or less.
| WO/2004/018084 | AERATION METHOD |
| JP2015160174 | WATER TREATMENT SYSTEM |
| JPH0648476 | [Name of invention] Cap that also serves as a hanger for hollow fiber type filters |
TAN KOICHI
FURUNO SHUJI
Next Patent: SOLID-LIQUID SEPARATION METHOD AND DEVICE