Tue Jul 17, 2012, 04:46 PM
MindMover (2,805 posts)
Researchers Consider Graphene as a Cure for Desalination Woes
The earth harbors about 1.4 billion cubic kilometers of water. Unfortunately, the vast majority of that water comes from the sea and is not potable unless treated by expensive, energy-hungry desalination plants. Those problems stem largely from inefficiency in the way salt ions are separated from water molecules, and the solution, says a team of materials scientists from the Massachusetts Institute of Technology, lies in fundamentally revising that process.
The predominant desalination method today—reverse osmosis (RO)—relies on polymer-based membranes to remove salt and requires great pressure to push water through a semipermeable film.The more pressure applied, the higher the cost. The M.I.T. researchers, led by Jeffrey Grossman and David Cohen-Tanugi, propose that films made of graphene could filter out salt without inhibiting the water flow as much. Graphene, a superstrong sheet of carbon that is only one atom thick, has mostly been seen as a material for improving electronics and optical communications.
Reverse osmosis requires less energy than other desalination approaches—such as thermal distillation—but graphene membranes containing nanoscale pores that are more permeable than the polymers currently used would further cut energy requirements, the researchers reported online last month in Nano Letters.
The idea is to discriminate between water molecules and salt ions based on size. "Reverse osmosis uses size exclusion, except it excludes everything," says Grossman, an associate professor of power engineering.
6 replies, 731 views
Researchers Consider Graphene as a Cure for Desalination Woes (Original post)
Response to MindMover (Original post)
Tue Jul 17, 2012, 04:59 PM
Gregorian (19,706 posts)
1. Fixing a symptom.
Last edited Tue Jul 17, 2012, 05:01 PM USA/ET - Edit history (1)
I'm wasting my breath. Full steam ahead! Keep growing!
However, one must admit it's an interesting possibility. And would fix present problems. But still, the easiest, cheapest, no engineering fix is staring us in the face.
Response to MindMover (Reply #2)
Tue Jul 17, 2012, 05:35 PM
Gregorian (19,706 posts)
5. Read my post. It would help present problems.
But only a few. And there are many many which aren't going to be addressed, nor even able to be.
I'll admit that my reply was semi-off topic. But I find it hard to resist bringing up what should be a well discussed and debated issue, but is essentially taboo.