If you have any doubts about the escalation in our need for fresh water measured against the diminishing supply, this document will definitely be the thorazine that’ll cure you of your delusionary ideation.
First of all, what most of us probably don’t realize is that, beyond seawater, there is a tremendous supply of underground aquifer water that we currently are not utilizing. You see, these aquifers are brackish --- the water non-potable --- containing excessive dissolved salts (not simply sodium chloride, but dissolved ionic species of many metal cations and a variety of anions (nitrates, sulfates, phosphates etc.). In other words, in order to become potable, this water requires desalination, by such membrane-based technologies as reverse osmosis (or others).
And this is just the tip of the iceberg of potentially available water: consider, for example, the approximately 500 billion gallons of non-potable water produced each year as a consequence of oil, natural gas, and coal-bed methane production. If this water could be treated for domestic consumption, it would equate to 23% of the daily water consumption of New Mexico (or 14% of Texas’ or 66% of Wyoming’s daily consumption).
So what me worry, right? Water shortages are a third-world problem; we’re America! Suck down that thorazine, amigo, estimates are that by the year 2020, 15 trillion additional annual gallons will be required in the US --- the equivalent of 25% of the combined outflow of ALL 5 great lakes.
Drowning yet? If not, then try wading neck-deep into the Second Law of Thermodynamics. Essentially, it tells us two very important things. First when you raise any physical entity to a higher-energy condition, you’ve got to put in energy from another source to do so. Logical, no? Water that’s 90 degrees is in a higher-energy condition than water at 50 degrees, so to heat it from 50 to 90, I have to add energy from somewhere else --- the gas or electric burners on my stovetop, for instance. Costs money --- ouch!
But the Second Law also has an entropy term. Very roughly speaking, that tells me that it also costs me energy to increase the order of anything; that is to go from disorder toward more order requires that I supply energy from another source. When you think about it, that’s what we’re trying to do in desalinating brackish water in which water and all manner of salts --- sodium, chloride, magnesium, nitrate, etc. etc. are all “mixed together” (we’re ignoring the variety of chemical bonds that makes this “mixing” something short of complete randomization). After desalination, we have established a more-orderly situation --- we have the water in one place and the dissolved salts in another separate place ---rather than all mixed together. Well, according to the Second Law, this takes energy, bubba, because it ain’t naturally what transpires. Fer instance, Vern, iffn’ you sneeze, the particulates and gases that come out of your nose get mixed up with the surrounding air in a sort of quasi-random way --- they, by all means, do not stay as ordered as they were prior to the sneeze --- when the gases and particulates were in your nose and the surrounding air was --- well --- the air surrounding your nose. And baby, when your body’s in the ground, it quickly goes to relative randomization ---from a very orderly to a quite disorderly state; of this, you can be assured. All those well-ordered structures, a heart, lungs, kidneys, etc., are going to end up as a disorganized glob of proteocarbolipid --- and eventually, as just carbon dioxide molecules skittering about.
So reverse osmosis (and other) technologies can take brackish water and fossil-energy-production (oil/natural gas) water and turn it to drinking water, but at what cost? Yeah, you got it --- energy. There’s the rub, and there’s the challenge, that is, to develop new, more energy-efficient desalination/purification technologies, and do it damned quickly. Some desalination researchers, for example, are trying to learn from Nature focusing on mimicking biological systems, which use proteins called “ion channels” and “aquaporins” to perform the salt/water separation feat --- gee, surprise surprise: Nature knows best!
It gets worse. For it turns out that there’s a lot more cost associated with disposal of the salts and other contaminants (collectively referred to as “concentrate”) that are separated from the water. And you thought that only the radioactive wastes from nuclear power plants were problematic. More thorazine --- the concentrated salt mixture has got to be disposed of. This is a complex problem that I won’t discuss here; suffice it to say that there are environmental implications and that it can be costly, so much so that it can be the determining factor in economic feasibility.
So for you Neanderthals out there who think that we (our national laboratories --- our collective national-security resource, for example) don’t need to invest in water purification research, PLEASE, THINK AGAIN (after you suck-down the thorazine). This is , unquestionably, an issue of national security. Let us hope that a passage from the “National Commitment Scenario” section of the report will come to fruition: “the failures of past R&D activities may be overcome, perhaps resulting in the creation of technologies that will be for future generations what reverse osmosis has been to ours. Public sector support for water purification R&D offers the nation one huge advantage in meeting its water supply needs: acceleration.