Water desalination as the cure for shortages
A couple of days ago, a study released by Nature Nanotechnology said a new graphene filter could be a major step forward in removing salt from seawater and making it safe for drinking. This is the big nut to crack in terms of water because the problem is not the lack of water per se but the lack of access to renewable drinking water. Some thoughts follow below.
As you know, I have been studying up on water and water technology because I believe this is going to be a growth area going forward – and one with big macro and geopolitical implications to boot. Some of the biggest global political issues right now have a lack of renewal water access at their source. I’m talking about African migration that is affecting the political situation in Europe, drought that is causing the largest humanitarian crisis in years, and wars like the one in Yemen where the US has been actively involved, conducting drone strikes on suspected terrorists it believes pose a threat to US security.
The United Nations says that 1.2 billion people – or about 20% of the world’s population— don’t have ready access to clean drinking water. Moreover, we saw water issues crop up in the US when California was hit with a drought over several years. So this has a given the US agriculture industry a taste of what others are experiencing.
Of course, 96.5% of the world’s water is seawater and totally unusable for human consumption. So people like the researchers from the University of Manchester in the nanotech study are working with things like graphene oxide membranes – essentially a molecular sieve – to allow some molecules to pass through while keeping others behind. The goal is to let just the water through, trapping salt ions that make the water non-potable.
Now, we have desalination techniques already online. For example, in Australia, Victoria’s desalination plant has gone online after four years’ construction. In March, the first 50 gigaliters of desalinated water began flowing into the Cardinia Reservoir there, with another 45 gigaliters expected to be ordered in the next three years.
Here’s the problem: the current desalination techniques – so-called multi-stage flash distillation and reverse osmosis — are expensive, energy intensive, and have a negative environmental impact. The reason these graphene membranes are considered so promising is that they can be produced relatively cheaply in lab environments. But these membranes are in their early stage of development and not ready to be produced on an industrial scale until kinks are worked out.
For me, this is promising. It doesn’t mean a solution to the water problem is around the corner. But it shows that people are working on one.