• Shreyans Water Engineers

Nano Filtration

Shreyans Water Engineers offers Nano Filtration. A nano-filtration membrane is also ion-selective. This is the ability to distinguish various ions from one another. Because a nano-filtration membrane collects solid loaded groups in its membrane structure, electrostatic repulsion/attraction forces may occur between the components in the liquid and the (nano-filtration) membrane surface, which results in a certain degree of ion selectivity. Based on the sieve effect (pore size 1 nm) and the molecular size of chlorides (0.12 nm in size) and sulphates (0.23 nm in size), these ions are expected to diffuse through the membrane. Despite this, the retention for chlorides is maximum 90 % and that of sulphates is minimum 90% (also see effectiveness paragraph). A nano-filtration membrane can be tubular, spiral or flat in shape. A spiral module (see figure below) consists of polyamide membrane layers wound in spiral form. At the edge of the membrane, the wound layers are sealed using a cap. A permeate collection tube is located in the centre of the wound module. All the clean water is passed through the spiral windings and collects in this tube.