The Pure Water Occasional for November 30, 2015
In this Thanksgiving Occasional, you’ll learn about the Goodpasture Bridge, photosolar nebulae, heavy hydrogen isotopes, bouncing water drops, the “bathing waters” of England, and the woes of Lake Chad. Good news about the San Marcos fluoride vote, the boom in water hauling, and the Thames Tideway Tunnel. Learn about water pollution by horses, pig bladder membranes, the ever-present plastic microbead, and the even more ever-present Erin Brockovich. The scary sinkhole on the Exmouth beach, the infamous Wet Prince of Bel-Air, and the modern version of walking on water. Then there’s Pure Water Annie explaining nominal vs.absolute filtration, a piece about ion exchange resins, new uses for ultraviolet, and, as always, there is much, much more.
The Pure Water Occasional is a project of Pure Water Products and the Pure Water Gazette.
To read this issue on the Pure Water Gazette’s website, please go here. (Recommended! When you read online you get the added advantage of the Gazette’s sidebar feed of the very latest world water news.)
Yet another attempt to explain the origin of the Earth’s water.
Earth may have kept its own water rather than getting it from asteroids
by Julia Rosen
Carl Sagan famously dubbed Earth the “pale blue dot” for our planet’s abundant water. But where this water came from—and when it arrived—has been a longstanding debate. Many scientists argue that Earth formed as a dry planet, and gained its water millions of years later through the impact of water-bearing asteroids or comets. But now, scientists say that Earth may have had water from the start, inheriting it directly from the swirling nebula that gave birth to the solar system. If true, the results suggest that water-rich planets may abound in the universe.
“This is a great test of our canonical picture for how Earth got its water, and it suggests that things are not as simple as we first thought,” says Fred Ciesla of the University of Chicago in Illinois, who was not involved in the new study. To understand the origin of Earth’s water, scientists have fingerprinted potential sources, like asteroids and comets, using the ratio of light to heavy hydrogen isotopes. Then, researchers can compare the ratios with those found in water sources on Earth.
However, researchers don’t really know the true hydrogen isotopic composition of Earth’s water, says Lydia Hallis, a planetary scientist at the University of Glasgow in the United Kingdom and lead author of the new study. Scientists have often assumed that the isotopic signature of seawater is close to the true value, but Hallis thinks this has probably changed over geologic time, as Earth preferentially lost light hydrogen atoms to space and gained water from asteroid and comet impacts.
So Hallis and her colleagues went looking for vestiges of the early Earth that might preserve the original hydrogen isotope ratio of the planet. They found them in an unlikely place: Baffin Island in the Canadian Arctic. Here, massive eruptions—fueled by the hot spot that now sits beneath Iceland—produced lava that originated deep in the mantle. So deep, in fact, that this material was probably isolated from the surface for almost all of Earth’s history. The evidence lies in the fact that the lavas, now hardened into basalts, still contain a fair amount of light helium isotopes, which would have escaped to space had the rocks spent much time anywhere near the surface.
In the new study, the researchers report the hydrogen isotope ratios of water trapped in glassy inclusions inside the basalts. The results, published online today in Science, reveal that the inclusions have a much lighter isotopic signature than does the ocean, suggesting that the composition of seawater has indeed evolved over time. Although scientists were aware of processes that could cause an isotopic shift in surface waters, Hallis says, “until we made our measurements, we didn’t know whether that would be a measureable difference or not.”
The new data suggest that the difference is vast. And Hallis suspects that the deepest, most primitive material in the mantle should have an even lighter isotopic composition than the inclusions her team measured. That’s because the rising magma that produced the lavas probably mixed with upper mantle rocks, which have been contaminated with isotopically heavy surface water that got dragged down by subducting slabs of tectonic plates.
So what does all this mean for the origin of Earth’s water? For one, the new data throw a wrench in the conventional story that carbonaceous chondrites—a water-rich variety of asteroid—delivered water to an initially dry Earth after its formation. That scenario has been bolstered by similarities in the isotopic signatures of the asteroids and seawater. But the chondrite signatures are too heavy to explain the deep Earth samples, Hallis says. “The carbonaceous chondrites don’t really work.”
Instead, Hallis and her colleagues propose that Earth’s water came directly from the protosolar nebula—the cloud of gas and dust that eventually clumped together to form the solar system. Based on measurements of Jupiter and the solar wind, which are thought to preserve the hydrogen isotopic ratio of the protosolar nebula, scientists think nebular water had an extremely light hydrogen isotopic signature—much closer to what the Baffin Island lavas suggest about the deep mantle’s water.
Traditionally, the main objection to this idea has been that the inner portion of the protosolar nebula, where Earth formed, would have been too hot for water to hang around. But Hallis’s team suggests that water floating around in the nebula snuck into our nascent planet by adsorbing to dust particles. They cite previous modeling work suggesting that this mechanism could allow a significant amount of water to survive the brutal temperatures and violent processes by which dust particles coalesced to form planets. Hallis says the discovery of a deep reservoir of material with protosolar isotope ratios supports the idea that the hot, early Earth somehow retained this water.
However, some scientists aren’t ready to abandon the asteroid hypothesis just yet. That’s because, on top of bringing water, they are also believed to have delivered much of Earth’s so-called volatile elements, namely, carbon, nitrogen, and noble gases, says Conel Alexander, a cosmochemist at the Carnegie Institution for Science in Washington, D.C. To explain the abundance of these elements, there would have had to have been enough impacts to also deliver Earth’s water, he says. “That still seems to me the simplest and most attractive explanation.”
Ciesla says that the new results will force scientists to re-evaluate the process of Earth’s formation. Perhaps the team’s adsorption model is correct, or perhaps water came to Earth aboard a kind of asteroid that hasn’t yet been found, or that no longer exists because it all went into making the Earth. “What we have to do is try to understand what fits and what doesn’t,” he says.
However, if Hallis and her colleagues turn out to be right, their hypothesis could have major implications for other planets. In the prevailing model of an initially dry Earth, hydrating the planet seemed like “more of a one-off event,” Hallis says. However, if the planet managed to keep water from the solar nebula before it evaporated away, there’s no reason other planets couldn’t do the same thing. Hallis says that her results could mean that water-rich planets like Earth are not so rare after all.
Pure Water Gazette Famous Water Pictures Series
The Goodpasture Bridge
Built in 1938, the Goodpasture Bridge spans the McKenzie River near the community of Vida in Lane County, Oregon. It is the second longest covered bridge and one of the most photographed covered bridges in the state. The Goodpasture Bridge is listed on the National Register of Historic Places. Around the US there are more covered bridges than one would think. Most have been preserved, at some considerable expense, because of their historical and aesthetic value.
–Model 77 is a thing of beauty and a joy forever. Plus, it has a lifetime warranty.--Pure Water Annie.Take a look.
Lake Chad Under Threat From Climate Change, Human Activity
by Moki Edwin Kindzeka
The once expansive and vital Lake Chad has lost as much as 90 percent of its water in the past 50 years. Experts from the six member states of the Lake Chad Basin Commission met in Cameroon to put together a plan to save the lake that will be presented at the Paris climate change summit in December.
The proposal centers on transferring water from the majestic 3.7 million square kilometer Congo River basin to the vanishing Lake Chad River basin. The Congo River basin is the second largest in the world, after the Amazon River basin.
Experts say that could improve the lives of over 40 million people in the countries that surround Lake Chad — Chad, Cameroon, the Central African Republic, Nigeria, Niger and Libya
Swaibou Mahaman, environmental expert at the Lake Chad Basin Commission, urged world leaders meeting in Paris to take the proposal seriously. He said the neighboring Congo River basin has enough water to help.
He said Lake Chad’s surface area has reduced by 90 percent from 25,000 square kilometers in 1960, but the population depending on the lake for their livelihoods has increased from 3.5 million to over 40 million inhabitants. He pointed out that figure is not including the animals, plants and birds that also exert pressure on the disappearing lake.
For the water transfer project to go forward, the governments of the Democratic Republic of Congo, the Central African Republic and the Republic of Congo must allow the Lake Chad Basin Commission to use their territories and water resources.
The experts say they await the green light in Paris. The project would cost $14.5 billion. No funding is currently available.
Deepening poverty around Lake Chad is also linked to regional insecurity, in particular the cross-border expansion of militant Nigerian sect Boko Haram.
Mana Boukary, representative of the executive secretary of the Lake Chad Basin Commission, said the commission also plans to canvas donors for $80 million to create jobs for youths.
Boukary said young people in the Lake Chad basin are joining the Boko Haram terrorist group because of lack of jobs and difficult economic conditions resulting from the drying up of the lake and the extinction of its resources that should have created livelihoods for them.
The drying up of Lake Chad has been attributed to changing weather patterns and human activity.
Source: Voice of America.
Writing in the journal Nature, Swiss researchers observed trampolining water droplets and what made them bounce and levitate as they did. Their findings are promising for real-world applications such as in keeping cars ice-free during winter. Read details in Tech Times.
Despite White House objections, the Senate voted for a resolution in early November to scrap new federal rules to protect smaller streams, tributaries and wetlands from development and pollution. Details.
A new government report showed a marked improvement in the quality of England’s “bathing waters.”
San Marcos, TX. A City Known for its Wonderful Water
San Marcos Frees Itself from Fluoridation
San Marcos, Texas, home of some of the earth’s most beautiful water, has artificially fluoridated the drinking water since 1987. Now, a major grassroots effort over the past year has brought that to an end. A strong coalition of campaigners, including Fluoride Free San Marcos and Texans for Accountable Government, weren’t discouraged by a city council that ignored their calls for an end to the practice. Instead, the multi-partisan coalition moved forward and collected the 1,600 signatures required to get a resolution amending the city charter on the ballot. Then another obstacle arose. Their referendum petition was illegally invalidated by the City Clerk, who even sued Fluoride Free San Marcos and three of its officers to have a judge void the petition and have the campaigners pay the city’s legal expenses. The judge ruled that the petition was legal, and directed the city to place the question on the ballot.
In a November 2015 election, voters in San Marcos (pop. 45,000) approved a resolution ending and prohibiting the fluoridation of the public water supply with 61% of the vote. Voters passed the following language into law: “The City of San Marcos shall not add, or direct or require its agents to add fluoride in the form of hydrofluorosilicic acid, hexafluorosilicic acid, or sodium silicofluoride to the San Marcos municipal water supply.”
San Marcos joins a growing number of US cities that are rejecting public fluoridation in spite of heavily financed opposition.
Water hauling becoming a booming business in CA
With the epic California drought heading into its fourth year, nearly the entire state is feeling the effects, with areas of southern California hardest hit. With mandatory water restrictions finally in effect across the state, Californians are feeling the pinch. Now farmers and homeowners alike are scrambling to change their ways to meet the new requirements.
As a result of the chaos and historically dry conditions, water trucks have become a booming business in the state. Enterprising small business owners are converting their construction equipment into water trucks to haul water from cities like Fresno to farmers in the Central valley who are growing desperate to keep their plants — and business prospects — alive.
If you plan to get in on the booming water hauling business, this article from ConstructionEquipment.Com will tell you everything you need to know about converting your truck to a water hauler.
Erin Brockovich has raised questions about the disinfection process used by the Tyler, TX municpal water system. This article gives an excellent account of how water treatment works.
London’s new state-of-the-art Thames Tideway Tunnel is set to bring environmental benefits worth up to almost £13bn. New figures show the benefits of the tunnel, which include preventing millions of tonnes of sewage flowing into the river every year, improving water quality to better protect marine wildlife and creating a cleaner river for all to enjoy. Details.
The chemistry of water found deep within the Earth suggests it has been there since our planet formed. The majority of Earth’s water may not have come from comets or asteroids as some scientists have argued. Full article from Tech Times.
A sizeable sinkhole opens on a beach in Exmouth when it rains. It is believed to be caused by blockage in a water pipe.
The Wet Prince of Bel-Air
An unnamed water user in Bel-Air made headlines last month for using 11.8 million gallons of water in a year, triggering widespread criticism of the “Wet Prince of Bel-Air.”That’s enough to supply more than 110 typical single-family homes or fill 21 Olympic-size swimming pools. Details from the LA Times.
And more about the Wet Prince
Outside her two-story tract home in this working-class town, Debbie Alberts, a part-time food service worker, has torn out most of the lawn. She has given up daily showers and cut her family’s water use nearly in half, to just 178 gallons per person each day.
A little more than 100 miles west, a resident of the fashionable Los Angeles hills has been labeled “the Wet Prince of Bel Air” after drinking up more than 30,000 gallons of water each day — the equivalent of 400 toilet flushes each hour with two showers running constantly, with enough water left over to keep the lawn perfectly green.
Only one of them has been fined for excessive water use: Ms. Alberts.
Read about the complexity and the inequality in California’s water rationing system in this interesting NY Times piece: In California, stingy water users are fined in drought, while the rich soak.
Rémy Bricka is walking across the Pacific Ocean. Because it is there, presumably. Details from Scientific American.
The total amount of groundwater on the planet, held in rock and soil below our feet, is estimated to be 23 million cubic km. If this volume is hard to visualise, imagine the Earth’s entire land surface covered in a layer some 180m deep. Read “Earth’s Underground Water Quantified,” a BBC Report.
Water Treatment Briefs
The process of osmosis was first discovered by a French scientist in 1748 who observed that water would flow spontaneously through a pig bladder membrane. The walls of living cells are semi-permeable membranes. “Reverse osmosis” works by using water pressure to push water in reverse of the natural flow of osmosis.
Water Treatment for Microbeads. The Occasional has printed several articles recently about concerns over the numerous plastic microbeads introduced into water supplies from a variety of medical, cosmetic, and industrial products. While attempts to regulate such products are in progress, most bans on microbeads will not take place before 2018 to 2020. In the meantime, removal of microbeads at point of use is feasible since microbeads can be as large as 1,000 microns in size. They can also be as small as < 6 microns. In general, filters that are capable of rejecting cysts like Giardia and Cryptosporidium should handle microbeads as well. Microbeads are not currently viewed as a serious threat to human health.
Use of Ultraviolet Treatment is expending. Once regarded as mainly a method for making well water safe, UV is now being used widely by city water users as a backup for city disinfection. In addition, UV is used increasingly to provide ultra-pure water for pharmaceutic applications, to disinfect wastewater, and to provide microbe-free water for horticultural applications. In swimming pools, UV is used both to treat microbes and to reduce chloramines. A more recent use is to control Legionella bacteria in warm water pipes in institutional settings.
New from Pure Water Products
We’ve recently added dome-hole equipped Vortech mineral tanks in the most popular 10″ X 54″ size. This allows us to offer calcite neutralizing filters in the popular Vortech tank, and it means that all of our residential backwashing filters are now provided in Vortech tanks. The Vortech tank provides not only better performance but a considerable water saving as compared with conventional gravel-bedded tanks. The dome-hole feature allows users to easily add calcite to the filter without having to removed the tank cap.
Common Uses of Ion Exchange Resins in Water Treatment
Ion exchange resin has been an effective water treatment tool for many years. The most common use, by a long way, is for water softening. Ion exchange resins, however, have many other less frequently used applications. Resins are used to reduce arsenic, nitrates, uranium, perchlorate, and more. They can also “deionize” water completely, removing the full mineral content.
Standard Softener Resin
Cation resins exchange positive ions and Anion resins treat negative ions. Here’s a chart showing types of resins and many of their uses:
|SAC – Strong Acid Cation||Water softening, iron reduction, barium and radium removal.||Exchanges for sodium ions. This is standard water softener resin.|
|WAC – Weak Acid Cation||Softens water (removes calcium and magnesium), reduces TDS mildly, and reduces alkalinity.||Has the often undesirable effect of lowering pH.|
|SBA – Strong Base Anion||Reduces nitrates, arsenic, perchlorate, TOC (Total Organic Carbon), uranium. Can also be used as an antimicrobial disinfectant.||Special grades with selectivity built in are often used.|
|SAC and SBA together.||SAC and SBA resins employed in combination, either individually or mixed together, can be used to reduce minerals and TDS in water.||The process is known as deionization (DI) or demineralization. The media can be placed in the same tank or in separate tanks.|
Indebted to “Ion Exchange Resins and Their Applications,” Water Technology, Nov. 2015.
Nominal vs. Absolute
If you’re puzzled by what filter makers mean when they call their filters “absolute” or “nominal,” technical wizard Pure Water Annie will clear the matter up for you.
Water filtration devices are rated by the sizes of particles that will pass through them. The ratings are normally expressed in microns.
Micron ratings are applied to all types of filtration devices, including even granular filters. It is said, for example, that a sand filter is roughly a 10 micron filter, meaning that it filters out particles ten microns and larger in girth. Carbon block filters are also assigned micron sizes, but micron ratings are most meaningful in comparing sediment filters.
The micron is a standard measure of size that is used by filter makers. The diameter of a human hair is about 90 microns. Sediment filters are used to catch particles 1/300 of that.
Most sediment filters are given ratings by their manufacturers that describe their effectiveness at removing particles down to a specified size. The most common of these are”nominal” and “absolute.”
Nominal, according to the Water Quality Association (WQA), means that the filter will filter out at least 85% of the particles of the size it is rated for. In other words, a filter that is rated as a 1 micron nominal can be expected to pick out 85% of the particles that are 1 micron or larger from the water that passes through it.
Absolute, theoretically, means that the filter will reject virtually all of the particles of the given size. The usual expectation is a 3-log rejection–or 99.9%. Absolute ratings are usually used for the tightest filters and for purposes where efficiency really matters. For example, if a filter maker promises removal of E. coli, more or less 85% efficiency isn’t good enough. If you’re going to trust your life to the filter, you expect an absolute 3-log or 4-log rating at the very least.
The problem with the absolute vs. nominal system is that there is really no universal standard that assures uniformity. Some makers of filters for non-critical applications, for example, might consider 70% rejection suitable for a nominal filter. Definitions vary from one manufacturer to another, and there is really no way for the end user to verify the claim.
For most common filtration issues filters rated as “nominal” are used. For example, a nominal 5 micron sediment filter is a standard size used in much residential water treatment.
Keep in mind that tighter is not always better. The lower the micron rating of a filter, the more it restricts flow. An absolute 1 micron filter is normally not a good choice for a residential sediment filter because there will be too much pressure loss. If you put in a filter to remove sand, a filter with a low micron rating is not only unnecessary, but it will also become clogged much faster than a looser filter.
Reference: The Pure Water Occasional.
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Thank you for reading. Please come back next week.
Places to Visit on Our Websites in the meantime.
Garden Hose Filters. Don’t be the last on your block to own one.
Model 77: “The World’s Greatest $77 Water Filter”
”Sprite Shower Filters: You’ll Sing Better!”
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