Desalination back in the day

Introductory articles about desalination invariably point out that simple schemes for desalting seawater have been practiced since very ancient times—sometimes to get at the salt rather than water. aristotle and quoteFor example, Waterblogged.info’s crack researchers have lost count of the number of times they’ve read that Aristotle wrote about a basic distillation process for separating salt and water. (He didn’t attempt to actually do it, but there’s a philosopher for you.)

The mini-history on this site states that there are references to desalination in ancient Egyptian, Sanskrit, Hebrew, Phoenician writings. The historical gloss here notes that the first recorded use of desalination was carried out by Japanese sailors using a system of earthenware jugs and bamboo tubes. All of this garners a collective shrug over here at Waterblogged.info headquarters, where we’re not at all surprised that ancient folk were smart enough to understand and utilize such obvious natural processes as evaporation and distillation. At any rate, Waterblogged.info, like the good web citizen it is, dutifully cites Aristotle and raises the bar by including a head shot and a quote.*

Relatively large-scale desal efforts took place much earlier than you might think, and much of it seemed to be driven by the need to supply ocean-going vessels with adequate drinking water. As far back as 1869, the first land-based steam distillation plant was established in Britain to deliver fresh water to ships. In his book, When Rivers Run Dry, global water expert Fred Pearce states that the first modern method for distillation of seawater was developed by the U.S. Navy to supply water to Pacific island bases during World War II.

Really large-scale desalting of seawater requires tremendous amounts of energy, and it has thus been a prohibitively expensive solution for most parts of the world. In the Middle East however, there is energy to ummm…burn, but very little fresh water. So it’s no surprise that the first really large-scale desalination plants were built in the freshwater-deprived and oil-glutted Gulf states.

Pearce also notes that roughly 20 percent of the world’s desalinated water—3 percent of the world’s drinking water supply (and 60 percent of that in the Middle East)—is produced by distillation. Waterblogged.info hastens to point out that this isn’t just about heating water and collecting all the little drops; state-of-the art seawater distillation is a complex, multi-step process, with a lot of variations. This paper about desalination technology provided by the California Coastal Commission will give the reader an overview that our overburdened staff has balked at writing.

But for concerned environmentalists—and until further notice Waterblogged.info stands proudly with them—large-scale desalination as the sole or even a major answer to replenishing rapidly disappearing fresh water is yet another Soviet desalination planthigh-tech fix that is going to do more harm than good. It will discourage the rescue and restoration of natural systems and water sources, diminish the already low level of enthusiasm for conservation, and possibly do great and irreparable harm to the oceans themselves. We will end up with a high-tech, industrialized dystopia of ugly, gigantic plants with huge, unwieldy, environment-unfriendly, and extremely costly distribution systems. (Full disclosure: Waterblogged.info has playfully included the photo of an old Soviet-era desal plant on the Caspian Sea. Under pressure from its editorial board, who see the image as misleading—probably because it’s most likely the ugliest example on the globe—Waterblogged.info directs you to a more positive image of desalination, albeit a futuristic fantasy, at Alexander Trevi’s wonderful Pruned.) See this list from Public Citizen to get a quick overview of the objections to desalination: Top 10 Reasons to Oppose Ocean Desalination.

* Don’t break out your ancient Greek dictionaries—it’s a fake quote. Here’s a real one:

“A tyrant must put on the appearance of uncommon devotion to religion. Subjects are less apprehensive of illegal treatment from a ruler whom they consider god-fearing and pious. On the other hand, they do less easily move against him, believing that he has the gods on his side.”

More Aristotelian musings here. There are myriad quotation sites, but this one performs the valuable service of ranking Aristotle against others quotable notables, presumably so that you don’t have to. )

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