Could this be the answer to overcoming droughts?
Standard water desalination plants are expensive things to both manufacture and run. Due to this only rich countries in areas where there is scarce rainfall can afford to use this process. Well what if this could be done at a fraction of the cost using Nanopores? A team of Engineers in the US have developed a type of material which allows massive volumes of water through minute holes – Nanopores but blocks out salt and contaminants.
What could this mean for the world and areas where drought is at times continuous?
The material they’re using – a nanometre-thick sheet of molybdenum disulphide (MoS2) riddled with these nanopore holes – is the most efficient of a number of thin-film membranes that the engineers modelled, filtering up to 70 percent more water than graphene.
“Even though we have a lot of water on this planet, there is very little that is drinkable,” said Narayana Aluru, a professor of mechanical science and engineering at the University of Illinois and leader of the study. “If we could find a low-cost, efficient way to purify sea water, we would be making good strides in solving the water crisis.”
Molybdenum disulphide coupled with nanopores could be that solution. While desalination isn’t a new concept, the efficiency gains with this kind of new material – both in terms of the energy required to make the filtration work, and also the cost of keeping a desalination system running – could make a world of difference when it comes to processing large amounts of seawater.
“Finding materials for efficient desalination has been a big issue, and I think this work lays the foundation for next-generation materials,” said Aluru. “These materials are efficient in terms of energy usage and fouling, which are issues that have plagued desalination technology for a long time.”
Conventional desalination relies on reverse osmosis to channel seawater through a thin plastic membrane, but the process suffers from a number of bottlenecks. While the membrane appears thin to the eye, from a microscopic perspective it’s more tube- or tunnel-like than a sheet that’s only a nanometre in thickness, which means it requires more pressure (and thus energy) to operate. They’re also susceptible to more clogging, which ramps up operational costs.
In comparison, the extreme thinness of the molybdenum disulphide membrane allows water to pass through with much less resistance, lessening or negating many of the above drawbacks. But the ingenuity behind the system isn’t just in its engineering.
This is an impressive design that may hold the answer to providing clean water from the masses of water that’s undrinkable across the planet. Let’s hope so.
featured image: Mohammad Heiranian/University of Illinois