I would like to ask about the separation precision of nanofiltration membranes

1. Purpose (1) Softening of water treatment； (2) Removal of harmful substances in drinking water in star-rated hotels, residential communities, and other facilities with differentiated water supply standards ； (3) Reclaimed water, wastewater treatment, etc ； (4) Concentration and refining (such as decolorization) in the food, beverage, and pharmaceutical industries ； (5) Concentration and separation of aqueous solutions in chemical process streams. 2. Working principle: There is no clear distinction between nanofiltration and reverse osmosis; in the early days it was referred to as a loose reverse osmosis membrane. The principle behind it is explained in the section on reverse osmosis principles. 3. Structure and characteristics of nanofiltration: NF membranes fall between RO and UF membranes; they are designed to remove solute particles with a diameter of around 1 nanometer (bivalent cations), and they can retain molecules with a molecular weight of 100–1000. Their most notable feature is that the membrane itself carries a charge, which enables it to maintain high desalination efficiency and a high capacity for retaining molecules even at low pressures. 4. The two main manufacturers are Hydronics and Dow. This post was last edited by chc1125 on 2008-11-10 11:01.]

I’m not quite sure what you mean; it seems unrelated to my question.

Based on my years of experimentation, it’s completely unfeasible!

Thanks for sharing your experience above. I’m a beginner in this area. So to what extent can nanofiltration membranes achieve separation? For example, below a molecular weight of 1000?

We need to analyze each case individually; the two molecules to be separated must have a sufficiently large difference in molecular weight. Alternatively, one can be an inorganic salt and the other a large-molecule organic compound. Please be more specific – you can send me an email at suminglue@filterox.com.

For membranes at the nanofiltration and reverse osmosis level, the molecular weight threshold for retention is merely a reference, as the mechanism at this stage is dissolution diffusion; it depends on the interaction between the membrane and the molecules to be separated. I have encountered several cases where larger molecules were able to pass through while smaller ones were retained.

Removing inorganic salts is definitely no problem, but I can’t say the same for anything else.

Recommendations from the poster: 1. For DOW products, use NF270 if the salt content is high, and NF90 if it is low. 2. For GE products, use DL if the salt content is high, and DK if it is low. The membrane can desalt, but sucrose with a higher molecular weight (340) in your solution will be concentrated along with organic compounds with a molecular weight of around 200.

Hello, Master. I am looking for a membrane that can separate sodium carbonate from water-soluble organic compounds with a molecular weight greater than 250. Is such a membrane available? You can’t send emails from your mailbox. My QQ number is 1010231970.

Hello, Master. I am looking for a membrane that can separate sodium carbonate from water-soluble organic compounds with a molecular weight greater than 250. Is such a membrane available? You can’t send emails from your mailbox. My QQ number is 1010231970.

Hello, Master. I am looking for a membrane that can separate sodium carbonate from water-soluble organic compounds with a molecular weight greater than 250. Is such a membrane available? You can’t send emails from your mailbox. My QQ number is 1010231970.

It’s completely impossible; think of other methods. Nanofiltration membranes cannot achieve pure separation