Non-treatment and blending techniques

As the quality of drinking water sources gets worse, the methods of water treatment or the traditional water treatment systems need to be modernized. Pressure-driven membrane systems such as reverse osmosis (RO), nanofiltration (NF) and ultrafiltration (UF) and electric-driven membrane system such as 

Some of the limitations to the use of ion exchange include the production of a highly concentrated waste by-product stream that poses a disposal problem (this problem can be reduced by brine recycling). Run length is affected by sulfate level. The technology is only recommended primarily for small groundwater systems with low sulfate and low TDS. Another limitation to its use is that it requires a high level of operator skill and therefore not popular with many end-users. 

---