Improved separation efficiency in nanofiltration by using a membrane stack Original Research Article

One of the major challenges of membrane filtration, the separation of organic solutes with relatively small differences in molecular size, is investigated by using a stack of up to three membranes in the same module. A rejection increase was observed for all solutes used, along with a flux decrease. The effect on rejection was significant but did not lead to a better separation of rejected and non-rejected solutes.