The basic principle of Nanofiltration membrane’s systems technology is to apply pressure to divide soluble ions from water through a semi-permeable membrane.
The membrane operates which is also known cross flow filtration, distinct from dead end filter systems. The majority Nanofiltration membranes are composite material supported by polymer substrate and manufactured in a spiral design system as different from a flat sheet or tube geometry. The leading model used today for industrial applications is the spiral configuration systems. Nanofiltration (NF) “bridges” a gap between UF systems and RO membranes systems. It is occasionally referred to as a loose or less rejecting RO membrane systems. It may possibly also be called a stretched UF, as NF membrane pore size from 0.01 to.001. Commonly, an NF membrane element lets more salt pass through than an RO membrane. In addition, an NF membrane element requires 50 to 70% less pressure than RO water treatment system. Where there are applications enough for 75% rate of salt rejection is preferable to 95 to 99%, mainly when it is achieved using only half of the energy consumed. NF, membrane NaCl rejection rate are more that 40%, Nanofiltration knew as “softening” membrane as while its salt rejection may be 80% or less, hardness rejection will sometimes remain well over 90%. The majority of NF membranes are spiral wound configuration. Applications of nanofiltration are: • Removal heavy metals from wastewater • Removal pesticides from groundwater • Wastewater recycling in laundry industry • For Water softening • For Nitrate removal
Examples of NF Applications:
Application Permeate Concentrate Benefits of NF Whey / Whey Permeate Salty wastewater Desalted whey concentrate Allows the recovery of lactose and whey protein concentrate with reduced salt content Textile Dyes 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 Water Softened water Hard water Potable water production. Softened water reduces scaling on equipment and heat exchange surfaces Antibiotics Salty waste product Desalted, concentrated Antibiotics NF produces high value pharmaceutical products