What is nanofiltration in water treatment?
A nanofiltration filter has a pore size around 0.001 micron. Nanofiltration removes most organic molecules, nearly all viruses, most of the natural organic matter and a range of salts. Nanofiltration removes divalent ions, which make water hard, so nanofiltration is often used to soften hard water.
What is nanofiltration process?
Nanofiltration is a pressure-driven membrane process that lies between ultrafiltration and reverse osmosis in terms of its ability to reject molecular or ionic species. Nanofiltration membranes, organic membranes, or ceramic membranes can be either dense or porous.
What are the application of nanofiltration?
Range of applications
| Industry | Uses |
|---|---|
| Fine chemistry and Pharmaceuticals | Non-thermal solvent recovery and management Room temperature solvent exchange |
| Oil and Petroleum chemistry | Removal of tar components in feed Purification of gas condensates |
| Bulk Chemistry | Product Polishing Continuous recovery of homogeneous catalysts |
Can nanofiltration remove TDS?
Nanofiltration has caught the attention of many for the purpose of water softening and the removal of various contaminants from drinking water. NF can reduce or remove TDS, hardness, color, agricultural chemicals, high molecular-weight, fulvic materials (which can form trihalomethanes when chlorinated).
What are nanofiltration membranes?
Nanofiltration (NF) is a membrane liquid-separation technology sharing many characteristics with reverse osmosis (RO). Unlike RO, which has high rejection of virtually all dissolved solutes, NF provides high rejection of multivalent ions, such as calcium, and low rejection of monovalent ions, such as chloride.
What is membrane structure in case of nanofiltration?
Nanofiltration membrane is a pressure-driven membrane, with a nominal molecular weight cutoff (molecular weight of solute that is 90 % rejected by the membrane) ranging from 200 to 1000 Da, pore size of around 0.2–2.0 nm, and operating pressures of 70–200 psi (5–15 bar) (Schäfer et al. 2002).
Which is best RO or NF?
NF delivers slightly coarser filtration than RO, with the ability to remove particles as small as 0.002 to 0.005 μm in diameter. NF is a relatively recent technology that was developed mainly for potable water generation.
What is the pore size of nanofiltration membrane?
0.2–2 nm
A nanofiltration (NF) membrane is classified as a pressure-driven membrane process, falling between a reverse osmosis (RO) and ultrafiltration (UF) membrane. It has pore size in the range of 0.2–2 nm with molecular weight cut-off (MWCO) from 200 to 1000 Da.
Which are the factors affecting the performance of nanofiltration?
The efficiency of the nanofiltration process is affected by fouling on the membrane and other factors like tangential velocity, pressure, temperature, turbulence, feed particles size, concentration polarization changes in membrane properties, and membrane characteristics [2].
What is the pore size of RO membrane?
reverse osmosis (RO, hyperfiltration): pore size < 1 nm (required pressure 10 – 70 bar) – removes microcontaminants and both polyvalent and monovalent ions (dissolved substances).
What is nanofiltration NF?
What is NF system?
The fundamental principle of Nanofiltration membrane’s technology is the use of pressure to separate soluble ions from water through a semi permeable membrane. The membrane, operates under a different hydraulic profile which is also known cross flow filtration, unlike a dead end filter.