Water treatment apparatus
AssigneesNitto Denko Corporation, Hydranautics
InventorsMasahiko Hirose, Atsushi Hiro, Mark Wilf
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Abstract
A water treatment apparatus according to the present invention includes a plurality of composite reverse osmosis membrane modules arranged in multi-stages, each of the modules including a porous support and a polyamide skin layer formed on the porous support. In this apparatus, the module at the final stage is supplied with some of permeated water obtained from at least one module preceding the module at the final-stage, 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.
Claims19
A water treatment apparatus comprising
- a 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.
Dependencies are inferred from the claim text.