ADVANCEMENTS IN OSMOTICALLY DRIVEN MEMBRANE SYSTEMS INCLUDING MULTI-STAGE PURIFICATION

摘要

An example water purification system for purifying high concentration feed solutions includes a high rejection forward osmosis module, one or more low rejection modules, and a high rejection reverse osmosis module. The low rejection modules may have different rejection levels. The system may be pressurized by one or more pumps. One or more of the low rejection modules may include one or more nanofiltration (NF) membranes. The draw solution may comprise a monovalent salt, a multivalent salt, or a combination of both.

主权项

1. An apparatus, comprising:
a forward osmosis module configured to receive a feed stream and a high concentration draw stream, wherein the forward osmosis module is further configured to produce a first stream comprising water from the feed stream and the high concentration draw stream; a pump configured to pressurize the first stream; a low rejection membrane module configured to receive the pressurized first stream and to produce the high concentration draw stream and a low concentration stream; and a reverse osmosis module configured to receive the low concentration stream and to produce a product stream and a reverse osmosis reject stream.