Those Saying Reverse Osmosis Will Not Power Large Scale Desalination May Be Right

As someone who was never really political until recently, I now get letters and notices of intent from Barbara Boxer and Diane Feinstein every so often, advising me of such things as the water shortage in California.

Because I know it is not true, as well as being a stickler for precision, I have written back that, in fact, there is no shortage of water in California whatsoever, as we live juxtaposed with the Pacific Ocean, a source of water beyond their wildest dreams. Then I focus the problem, what we lack is clean, potable water.

When I wrote back with the details of large scale reverse osmosis, I included that my experience was personal, as I worked with reverse osmosis equipment at one of my first jobs. I was very involved in its use in a manufacturing process, where rinse water for a copper foil production system was recycled, with the “waste stream” being recycled to the makeup water for the copper sulfate solution that was the genesis of the copper foil that was electroplated on stainless steel drums. The product water was very clean, going from approximately 2500 milligrams per liter to roughly 20 parts per million copper, in a one pass process.

It is not a cheap, nor energy efficient process, but, as I have pointed out, we also have a surfeit of sunshine in California, and that can be used to generate electricity photovoltaicly, to power the reverse osmosis treatment.

I have gotten no replies to my letters from either of them. I doubt they know what to say to someone who states that all it takes is will, and should they want to do something, gathering some of that up would be the best course of action.

Now, a story in slashdot tells us that the best method might be a bit more energy efficient, using a completely different method (by the way, the RO method is used worldwide to reclaim brackish water, and is recognized as extremely efficacious, but is very energy intensive.)

“The Economist reports on progress by a company called Saltworks on using saline gradients to do the heavy lifting of desalination. In essence, Saltworks uses solar energy or waste heat to concentrate sea water. They then use the ionic gradient between the concentrated brine and two sea-water streams to pull ions from from a 3rd sea-water stream. It appears to work with entropy by trading the reduced entropy of the desalinated water against the increased entropy of ‘mixing’ the brine and the other sea-water streams. The article only discusses Na and Cl, but even just removing these ions is a step in the right direction.”

This is certainly good news, because any energy savings means that no new photovoltaics would need be built simply to power the desalination through RO. It shows that new ideas are being developed all the time, and that if we are to solve all of our problems in this world, technology will certainly be our best friend, and education of our people is paramount.

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Quote of the day:

If you would be a real seeker after truth, it is necessary that at least once in your life you doubt, as far as possible, all things.

- Rene Descartes

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