As advances in nanofiltration (NF) continue to stream into the global marketplace, Koch Membrane Systems continues to maintain its established role as the prime innovator.

Koch manufactures nanofiltration membranes in tubular, spiral and flat sheet membrane configurations.

• Retains divalent salts and organics
• Passes monovalent salts, water, acid and alkaline compounds
• Pore sizes ranging between UF and RO

Nanofiltration is a low to moderately high pressure (typically 50 - 450 psig) process in which monovalent ions will pass freely through the membrane but highly charged, multivalent salts and low molecular weight organics will be rejected to a much greater degree. Typical NF applications include water softening, desalination of dyestuffs, acid and caustic recovery and color removal.

Take a Closer Look at KMS Advanced Nanofiltration (NF)

Koch crossflow membrane filtration controls the effect of concentration polarization and the gel layer. It provides the most rapid, and hence economic, continuous membrane filtration.

NF is a pressure driven process for separating larger size solutes from aqueous solutions by means of a semi-permeable membrane. This process is carried out by having a process solution flow along a membrane surface under pressure. Crossflow membrane filtration uses a high cross flow rate to enhance permeate passage and reduce membrane fouling. Retained solutes (such as dissolved salts) leave with the flowing process stream and do not accumulate on the membrane surface.

Pores have not been observed in NF membranes under any microscope, however, water can still pass through the membrane and multivalent salts and low molecular weight organics are rejected. It is difficult to predict the performance of NF membranes, especially if more than three solutes are present in the solution, since membrane rejection is influenced by the size, structure and charge of the components in solution. As a result, piloting is highly recommended for NF applications, even if a detailed feed water analysis is available.

Koch offers its SelRO® line of solvent-stable and pH-stable NF membranes as well as the SR® and TFC® or TFC®-S NF membranes.

Examples of NF Applications




Benefits of NF

Whey / Whey Permeate

Salty wastewater

Desalted whey concentrate

Allows the recovery of lactose and whey protein concentrate with reduced salt content



Water, salts, BOD, COD and color

NF is used to desalt  dyes resulting in a higher value product

Caustic cleaning solutions

Caustic cleaning solution

BOD, COD, suspended solids, caustic cleaner

Allows caustic cleaning solution to be recycled resulting in reduced cleaning chemical costs

Recycle of acid solutions

Acid solution

BOD, COD, calcium, suspended solids, acidic water

Allows acid solution to be recycled resulting in reduced cleaning chemical costs


Softened water

Hard water

Potable water production. Softened water reduces scaling on equipment and heat exchange surfaces


Salty waste product

Desalted, concentrated Antibiotics

NF produces high value pharmaceutical products

Call us first! We want to help you choose the right solution for your application. Take advantage of over 13 years of water treatment experience. Performance is everything! Phone 09444021237 or get in touch with us through the contact us page.
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