The Pure Water Occasional is a weekly email magazine produced by Pure Water Products of Denton, Texas. We also serve up the Pure Water Gazette, which offers new articles about water and water treatment daily, furnishing readers “vast piles of information in the Gazette’s tangy, irreverent style” (Macon Express). We sincerely invite you to visit PureWaterProducts.com, a commercial website that is packed to the brim with valuable water treatment information. If you would like to read this issue on the Pure Water Gazette’s website, please go here.
While you were sorting through your new school clothes to decide which to return to the stores, a lot of interesting things happened in the ever-changing world of water. Read on to hear about some of them.
New From the Pure Water Gazette:
Why the Seas Rise
Adapted from Rising Seas by Tim Folger.
Unless we change course dramatically in the coming years, our carbon emissions will create a world utterly different in its very geography from the one in which our species evolved. “With business as usual, the concentration of carbon dioxide in the atmosphere will reach around a thousand parts per million by the end of the century,” says Gavin Foster, a geochemist at the University of Southampton in England. Such concentrations, he says, haven’t been seen on Earth since the early Eocene epoch, 50 million years ago, when the planet was completely ice free. According to the U.S. Geological Survey, sea level on an iceless Earth would be as much as 216 feet higher than it is today. It might take thousands of years and more than a thousand parts per million to create such a world—but if we burn all the fossil fuels, we will get there.
No matter how much we reduce our greenhouse gas emissions, Foster says, we’re already locked in to at least several feet of sea-level rise, and perhaps several dozens of feet, as the planet slowly adjusts to the amount of carbon that’s in the atmosphere already. A recent Dutch study predicted that the Netherlands could engineer solutions at a manageable cost to a rise of as much as five meters, or 16 feet. Poorer countries will struggle to adapt to much less. At different times in different places, engineering solutions will no longer suffice. Then the retreat from the coast will begin. In some places there will be no higher ground to retreat to.
By the next century, if not sooner, large numbers of people will have to abandon coastal areas in Florida and other parts of the world. Some researchers fear a flood tide of climate-change refugees. “From the Bahamas to Bangladesh and a major amount of Florida, we’ll all have to move, and we may have to move at the same time,” says Wanless. “We’re going to see civil unrest, war. You just wonder how—or if—civilization will function. How thin are the threads that hold it all together? We can’t comprehend this. We think Miami has always been here and will always be here. How do you get people to realize that Miami—or London—will not always be there?”
What will New York look like in 200 years? Klaus Jacob, the Columbia geophysicist, sees downtown Manhattan as a kind of Venice, subject to periodic flooding, perhaps with canals and yellow water cabs. Much of the city’s population, he says, will gather on high ground in the other boroughs. “High ground will become expensive, waterfront will become cheap,” he says. But among New Yorkers, as among the rest of us, the idea that the sea is going to rise—a lot—hasn’t really sunk in yet. Of the thousands of people in New York State whose homes were badly damaged or destroyed by Sandy’s surge, only 10 to 15 percent are expected to accept the state’s offer to buy them out at their homes’ pre-storm value. The rest plan to rebuild.
This isn’t an artist’s vision of what New York will look like in 2210. It is a photo of present-day Manila where the rising sea keeps nibbling away at the waterfront homes of the poor.
Source: National Geographic.
Pure Water Gazette Fair Use Statement
An exact definition of what is commonly called “brackish” water is hard to pin down. Brackish water falls between seawater and fresh water. Brackish water is similar to seawater except the salt content is less, as are the TDS (total dissolved solids). In another way of classifying, you start with fresh water, then go to brackish water, then to saline water, then to brine. The specifics of these classifications are often blurred.
The word "brackish" comes from the Middle Dutch root “brak,” meaning “salten” or “salty."
Brackish Water Pond
One authority states that brackish water begins at about 1000 ppm TDS and runs upward to around 10,000 or 12,000 ppm TDS.
The basic process of treating brackish water in desalination applications is to pass pressurized water through a membrane. As fresh water passes through the membrane, brine or wastewater is rejected. Seawater treatment applications differ from brackish mainly in the level of osmotic pressure required to achieve fresh water. Typically, the pressure needed ranges in brackish water treatment from 5 psi to 75 psi, although the majority of brackish applications fall in the 145 psi to 290 psi range.
Brackish water is generally a surface-type water and as such can be influenced by such environmental factors as rainfall and humidity. Ion levels and bacteria could be higher in the summer months compared to winter months, and salinity, nitrates, iron, silica and bacteria are a few examples of what is common in untreated brackish water. Viewed another way, brackish water is water that has more salinity than fresh water, but not as much as seawater. It may result from mixing of seawater with fresh water, as in estuaries, or it may occur in brackish fossil aquifers.
Certain human activities can produce brackish water, in particular certain civil engineering projects such as dikes and the flooding of coastal marshland to produce brackish water pools for freshwater prawn farming. Brackish water is also the primary waste product of the salinity gradient power process. Because brackish water is hostile to the growth of most terrestrial plant species, without appropriate management it is damaging to the environment.
Technically, brackish water contains between 0.5 and 30 grams of salt per litre—more often expressed as 0.5 to 30 parts per thousand (ppt or ‰). Thus, brackish covers a range of salinity regimes and is not considered a precisely defined condition. It is characteristic of many brackish surface waters that their salinity can vary considerably over space and/or time. Here is a chart from the Wikipedia:
Water salinity based on dissolved salts in parts per thousand (ppt)
0.5 – 30
30 – 50
In summary, brackish water lies in definition somewhere between fresh water and sea water and is defined mainly by its salt content. Treatment is almost exclusively by membrane technology (reverse osmosis) or by distillation.
More from the Pure Water Gazette. Read these new items on the Gazette's website:
Severe Drought Is Bad News for Lake Powell Water Recipients by Dennis Wagner
Modern undersink reverse osmosis units use a simple but effective shutoff device to turn off water production when the unit’s storage tank is full. The shutoff system monitors the pressure in the storage tank and shuts off water coming into the RO membrane when tank pressure reaches approximately 2/3 of the pressure of the incoming tap water.
Stepping Out of the Bubble, by Elizabeth Cutright.
Just as there are global warming sceptics, there are water shortage deniers. In this article, the editor of Water Efficiency takes a look at the latter.
The basics of understanding the small threaded fittings used on water treatment equipment.
Water News from Around the World
Shannon, Quebec, is a town that has been plagued by abnormally high rates of certain cancers. Medical professionals have pointed the finger at the town’s Valcartier military base, where trichloroethylene (TCE) – a solvent which strips grease from metal – was used by a munitions manufacturer for more than 40 years. Although it was confirmed in 1997 that the solvent had seeped into the town’s water supply, residents say repeated calls for a full investigation have fallen on deaf ears. Full Story.
In America, people buy more soft drinks per capita than in any other country. Soft drink consumption reaches across all age groups, from the very young to the very old. Although associated with aggression, depression, and suicidal thoughts in adolescents, the relationship between soft drink consumption and younger children had yet to be evaluated. In a new study conducted at Columbia University that delves into this connection, researchers found that problems of aggression, attention difficulties, and withdrawal behavior are all associated with soft drink consumption in young children. Full Story.
In this July 10, 2012, photo a duck swims along the Bay of Green Bay shoreline near an accumulation of algae near the University of Wisconsin-Green Bay. Scientists say Lake Michigan’s Green Bay is developing “dead zones” similar to sections of Lake Erie and the Gulf of Mexico, where there’s so little oxygen that few if any organisms can survive. In a web presentation Thursday, Aug. 15, 2013, experts said the primary culprit is excessive levels of nutrients such as phosphorus that wash into the Wisconsin bay from farms, industry and municipal wastewater treatment systems. Full Story.
President Rafael Correa said last week that he has abandoned a unique and ambitious plan to persuade rich countries to pay Ecuador not to drill for oil in a pristine Amazon rainforest preserve.
Environmentalist had hailed the initiative when Correa first proposed it in 2007, saying he was setting a precedent in the fight against global warming by lowering the high cost to poor countries of preserving the environment.
"The world has failed us," Correa said in a nationally televised speech. He said the global recession was in part responsible but chiefly blamed "the great hypocrisy" of nations who emit most of the world's greenhouse gases. Full Story.
Coming soon to Pure Water Products: Sterilight Ultraviolet and other excellent Viqua products.
Thank you for reading, and please stay tuned next Monday for another inspiring Occasional.
Places to Visit on Our Websites in the meantime
Model 77: “The World’s Greatest $77 Water Filter”
”Sprite Shower Filters: You’ll Sing Better!”
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