HOLLOW FIBER MEMBRANE, HOLLOW FIBER MEMBRANE PRODUCTION METHOD, HOLLOW FIBER MEMBRANE MODULE, MEMBRANE SEPARATOR, AND MEMBRANE SEPARATION METHOD

摘要

A hollow fiber membrane that is a hollow-fiber-type semi-permeable membrane. The shrinkage rate of the inner diameter of the hollow fiber membrane after usage for 96 hours in a prescribed membrane separation method is 0.1% or more and less than 9% of the inner diameter at the start of usage. In the prescribed membrane separation method, a hollow fiber membrane module having the hollow fiber membrane and a first chamber and a second chamber partitioned by the hollow fiber membrane is used to cause a first liquid to flow into the first chamber at a first pressure and a second liquid to flow into the second chamber at a second pressure lower than the first pressure, whereby water included in the first liquid in the first chamber is transferred via the hollow fiber membrane to the second liquid in the second chamber, a concentrated liquid which is the concentrated first liquid is discharged from the first chamber, and a diluted liquid which is the diluted second liquid is discharged from the second chamber. An outer space of the hollow fiber membrane is the first chamber and an inner space of the hollow fiber membrane is the second chamber. The first pressure is 5.0 MPa, the second pressure is constant, and the osmotic pressure difference between the first liquid and the second liquid is 0 MPa.