Why would I need one?
Whenever it is a requirement to remove a proportion of the mineral content of a water supply but leave a substantial amount of mineral in the water.
When would I use it?
For compliance with various standards and manufacturers specifications.
Examples include Brewing, Food Processing, Adiabatic Cooling, Cooling Towers, Irrigation and many more applications.
What is it?
It is a process similar looking plant wise to Reverse Osmosis but typically only removes about 50%-70% of the total dissolved solids (TDS) in water.
The pore size of a nanofiltration membrane is normally about 1000 times greater than an RO membrane so allows a greater proportion of minerals through than RO.
The process can be used to recover reject from an RO plant and send it back to the inlet side of an RO to be reprocessed and increase the total recovery rates of a system.
What is the benefit?
On most waters it has the advantage of not requiring dangerous regenerant chemicals and a discharge water that can be reutilised for further low-grade use. Normally the cost per unit of water processed is much lower than traditional methods of production.
It also allows water that may not have conformed to the EU drinking water directive to be made potable.