Membrane technology refers to a number of different, characteristic separation processes. In each of them a membrane is used to separate suspended or dissolved solids from water.

Reverse osmosis:

Reverse osmosis (RO) is a water purification process that removes impurities and minerals from water by forcing a concentrated solution, such as salt water, through a semipermeable membrane. This semipermeable membranes allows only the water molecules through and stops other molecules.

Ultrafiltration:

Ultrafiltration is pressure-driven purification process in which water is forced through an ultrafine membrane to remove contaminants completely, from solids to bacteria and viruses