Desalination using Graphene

Published on by in Technology

Can someone please help with more details on "membrane 'sieve' capable of removing salt from seawater to make it drinkable by using graphene, a wafer-thin sheet of carbon atoms". We have been contacted by someone who wants to implement it to their town and needs necessary details related to project and its cost and uses to cultivation etc along with power point presentation with documents.

Taxonomy

5 Answers

  3. Graphene has many unusual properties. It is about 200 times stronger than the strongest steel.Graphene is an allotrope of carbon in the form of a two-dimensional, atomic-scale, hexagonal lattice in which one atom forms each vertex. Graphene, which results from slicing off an atom-thick layer of graphite, is increasingly emerging as something of a wonder material. The Grossman Group, for example, is also looking into using it as a cheaper alternative to silicon for making solar cells. It is the basic structural element of other allotropes, including graphite charcoal carbon nanotubes and fullerenes. It can be considered as an indefinitely largearomatic molecule, the ultimate case of the family of flat polycyclic aromatic hydrocarbon.

    By creating nanoscale pores in a layer of graphene, it could be used as an effective separation membrane due to its chemical and mechanical stability, its flexibility and, most importantly, its one-atom thickness. Theoretical studies have indicated that the performance of such membranes should be superior to state-of-the-art polymer-based filtration membrane. perforated graphene filters can handle the water pressures of desalination plants while offering hundreds of times better permeability,” says Grossman. “The process of pumping seawater through filters represents about half the operating costs of a desalination plant. With graphene, we could use 15 percent less energy for seawater and up to 50 percent less energy for brackish water.”

    http://ilp.mit.edu/videodetail.jsp?confid=null&id=1488#

     

  4. The new findings are from a group of scientists at The University of Manchester which was published in the journal Nature Nanotechnology in January 2017. They have now developed new graphene based membrane that can avoid the swelling of the membrane when exposed to water which was not previously possible. They are able control the pore size in the membrane up to very small level which can sieve common salts out of salty water and make it safe to drink.

    The experiment has been done on laboratory scale with a membrane of size less than 1 cm2 and showed that reducing the pore size did not affect much on the water flux but improved salt rejection compared to previously developed graphene membrane. Moreover, they did not perform any desalting experiment and only used as forward osmosis (FO) membrane where no pressure is applied. FO experiment showed that it has salt rejection of only 97% with water flux 0.5 lmh, which is not commercially attractive. In order to make these membranes commercially attractive, it need further improvement in its performance in terms of flux as well as salt rejection and also shall be capable of scaling up to larger system. None of these are observed in the present findings and hence we need to wait and watch for further developments in this regard.