Water, water, everywhere... and how much might we drink?

It's been centuries since Coleridge's Ancient Mariner lamented the undrinkable salty seas around him. Today, it's easier -- but not necessarily easy -- to get fresh water from the vast water reserves of the world's oceans. Over 15,000 desalinization plants now operate throughout the world, but they produce less than 1% of the water the world consumes every day. Population growth and water scarcity often go hand in hand, so anything that could enhance the usefulness of desalinization efforts would be well-received everywhere.

A recent press release from defense contractor Lockheed Martin (NYSE:LMT) offers a great deal of hope that desalinization might become a lot easier and a lot cheaper. Desalinization is an energy-intensive process, requiring great pressure to force water through plastic polymers while separating out the salt and other undesirable substrates. The less pressure -- and thus, less energy -- that's required to filter out potable water, the easier it would be to place desalinization plants in areas that need it most.

Lockheed's innovation makes use of graphene, an atom-thin sheet of pure carbon that's arranged in a hexagonal pattern. Pencil lead displays a similar structure, but it's obviously too thick to be of much use as a filter. The development of graphene won the Nobel Prize in 2010, and researchers are already looking for many other ways to apply it to industrial problems. Applying graphene to water filtration problems seems not only sensible, but inevitable -- Lockheed simply got there first.

Lockheed's innovation, a perforated graphene sheet called Perforene, is already in production at the company's Palo Alto technology center. It's 1,000 times stronger than steel but 100 times as permeable as competing membranes. However, that strength comes on a single-atom sheet, which is still going to be delicate when applied to industrial uses. Lockheed claims to be a year or two away from prototype testing, and by the time Perforene is ready for action there may be 107 million cubic meters of desalinization capacity already at work around the world. That's a doubling of capacity from 2008, and an estimated $64 billion will be spent on this capacity growth. If Perforene can provide the same functionality at a fraction of the energy cost, it's quite feasible to expect the next decade of desalinization build-out to be far more intense.

If Perforene proves effective, it might lead to the development of smaller, more distributed desalinization machinery for the developing world. However, there's also something to be said for economies of scale, and the owners of those 15,000 desalinization plants aren't likely to close up shop just because a few portable desalinization devices start cropping up. The only notable publicly-traded desalinization play is Caribbean-based Consolidated Water (NASDAQ:CWCO), which could see some impressive cost savings in its existing plants. As my fellow Fool Jacob Roche points out, Consolidated Water has been expanding beyond its Caribbean footprint. Improved filtration technology is likely to hasten that growth on the back of much-improved energy efficiency.

However, a more effective filtration system is hardly limited to straining the sea out of seawater. Wastewater treatment plants would also benefit, and here the opportunity is far greater for large industry players. Aqua America (NYSE:WTR) has been expanding into wastewater treatment this year, and American Water Works (NYSE:AWK) already claims to be America's largest public wastewater services company. Veolia Environnement (OTC:VEOEY)also maintains some desalinization plants in addition to its core water and wastewater services.

In fact, better filtration need not be confined to water at all. It could be used in medical applications, chemical processes, air purification... if you can think of something that benefits from filtration, Lockheed's Perforene might someday be there to improve it.