초록 ▼

A nanofiltration process using a conventional nanofiltration membrane module under a positive applied pressure is used to selectively change the concentration of one solute, such as sodium chloride or sodium chlorate providing monovalent ions, from another solute such as sodium sulfate or sodium dic

A nanofiltration process using a conventional nanofiltration membrane module under a positive applied pressure is used to selectively change the concentration of one solute, such as sodium chloride or sodium chlorate providing monovalent ions, from another solute such as sodium sulfate or sodium dichromate providing multivalent ions in high salt aqueous concentrations. The process is particularly useful in favourably lowering the concentration of silica and dichromate ions in chloral kali and chlorate brine containing solutions and favourably raising the sodium sulphate level relative to sodium chloride in chloraldhali liquor. The relatively high salt concentration, surprisingly, effects little or no monovalent, particularly, Cl-rejection.

대표청구항 ▼

In a nanofiltration process for filtering an aqueous liquor comprising feeding a feed liquor to a nanofiltration membrane module under a positive applied pressure to provide a pass liquor and a permeate liquor and selectively decreasing the concentration of a first compound relative to the concentra

In a nanofiltration process for filtering an aqueous liquor comprising feeding a feed liquor to a nanofiltration membrane module under a positive applied pressure to provide a pass liquor and a permeate liquor and selectively decreasing the concentration of a first compound relative to the concentration of a second compound in said aqueous liquor wherein said first compound has a first feed concentration and said second compound has a second feed concentration, said process comprising feeding said aqueous liquor to said nanofiltration membrane module, collecting said pass liquor wherein said first compound is at a first pass concentration lower than said first feed concentration, and said second compound is at a second pass concentration higher than said second feed concentration, and collecting said permeate liquor wherein said first compound has a first permeate concentration and said second compound is at a second permeate concentration, the improvement wherein said first feed compound has a first feed concentration greater than 50 g/l, wherein said first feed compound contains monovalent ions, and said second feed compound contains polyvalent ions.