Nanofiltration for water purification
Introduction
Nanofiltration is the process by which a fluid is passed through a semipermeable membrane at a certain pressure so that a separation is produced based on the size of the molecules that can cross said membrane (between 0.001 and 0.01 mm). Two streams of the inlet fluid are obtained: the permeate, which is the fluid that has passed through the membrane and from which the components whose molecular weight is greater than the pore size of the membrane have been removed, and the concentrate, which corresponds to the fluid that has not crossed the membrane and which concentrates the components of the main stream.
The technique is mainly applied in the purification of water, drinking water, the elimination of organic substances, such as micropollutants and multivalent ions. Nanofiltration membranes moderately retain univalent salts.
Other applications of nanofiltration are:
Materials
The materials, called MOFs, or metal-organic frameworks, and sometimes described as "glass sponges," have previously shown great potential for storing hydrogen and methane. At the molecular level, MOFs are scaffolds composed of metal cubes linked together by beams of organic compounds, a structure designed to maximize surface area.
The University of Adelaide is an Australian public university with a university campus in the city of Adelaide, in South Australia, and one of the best in the world, for this reason it seeks to be a pioneer in various types of research, among the innovations it has presented is a proposal that could be the answer to help reduce CO and thus eliminate its harmful effects. A group of scientists made up of members of the university developed a new material with nanotechnology to reduce the pollution generated by power plants powered by fossil fuels. This new material serves to separate carbon dioxide (CO) from nitrogen, another of the components that are released in power plants when they burn coal. This greatly facilitates the absorption of CO, preventing its release into the atmosphere, which would counteract one of the great problems facing man: the greenhouse effect.
It also has an ultra-absorbent quality called organometallic framework, which has the ability to efficiently separate CO from nitrogen. The material is very similar to a sponge, but on a nanometric scale and its microscopic pores retain the CO molecules, while the nitrogen molecules, which are a little larger, remain outside. There are other methods of CO absorption, but they are very expensive and consume a lot of energy. This new nanomaterial promises to be much more energy efficient, plus it is very easy to manufacture.