Patent ID: 6805796
Filing Date: 2004-10-19
Classification: B01D,C02F

Abstract:
A water treatment apparatus comprisinga plurality of composite reverse osmosis membrane modules arranged in multi-stages, each of the plurality of modules including a porous support and a polyamide skin layer formed on the porous support, the plurality of modules including a final-stage module and at least one pre-final module, wherein the polyamide skin layer in the at least one pre-final module comprises bromine atoms introduced into the polyamide skin layer by treating the polyamide skin layer with a free chlorine aqueous solution containing a bromine compound, wherein a selected portion of permeated water obtained from the at least one pre-final module is supplied to the final-stage module, and a rest of the permeated water is discharged from or recovered in the apparatus along with permeated water obtained from the final-stage module.