Nanofiltration (NF) technology acts as a bridge between UF and RO membranes in water treatment technology. The size of the pores in the membranes used range from 0.01 to 0.001 microns. For this reason NF can be used either as an RO with a lower rejection rate (an NF membrane will produce the same quantity of product at up to half the pressure as an RO membrane) or as a tight UF system. Nanofiltration is commonly used to soften water because hardness rejection is well over 90%. The high active membrane area combined with the low net driving pressure of the membrane allows the removal of many compounds at low operating pressures. When it comes to salt rejection it is less effective than RO, but there are some applications where a 70% rate of salt rate rejection is preferable to 95+% because it is achieved using only half the amount of energy. Some of the most common applications of NF are:
- Nitrate removal
- Wastewater recycling esp. laundries
- Removal of pesticides from surface or underground water
- Removal of heavy metals from wastewater
- Pre-treatment for RO
- Water softening
- ABEL offers expertly designed NF systems, custom-made to solve our client’s problems.
