Today
World Water Day 2017: Our polluted waters
http://www.msn.com/en-us/news/world/...tandhp#image=2
Today
World Water Day 2017: Our polluted waters
http://www.msn.com/en-us/news/world/...tandhp#image=2
'How and Why ?' ~ Einstein
Thanks for sharing messes from other countries. They should clean up their environments. Personally, I'm so happy that the Ohio EPA has stepped up over the years and enforced state law in cleaning the lakes and rivers in Ohio. We must have our state EP agencies remain ever vigilant.
Any time you give a man something he doesn't earn, you cheapen him. Our kids earn what they get, and that includes respect. -- Woody Hayes
India is a $#@!hole par excellence! people drink the same waters they $#@! in and bathe in, and worship rats!
Pakistan runnin' outta water...
Pakistan on Verge of Disastrous Water Shortage
April 03, 2017 — Two weeks ago a minor water crisis hit Pakistan. The flow in rivers fell below agricultural requirements. Then temperatures rose, glaciers melted, and river flows increased threefold, evading a disaster.
See also:“Had the temperatures not increased for another 10-15 days, we wouldn’t have been able to give the required amount of water to the provinces,” said Mohammad Khalid Rana, the Indus Water Regulatory Authority spokesman. That would have meant a delay in planting crops like cotton, sugarcane, and rice. The fluctuation in river flows, blamed mostly on climate change, was not unprecedented. Nor was it unexpected. Yet its solution does not appear to be in the works, for the near future. “If we want to ensure our food security and meet our climate change challenges, we’ll have to increase our water storage on a war footing,” warns Rana.
Even though Rana works for a government agency, his warnings appear to be making little difference in policy, according to independent water experts. Pakistan started off as a water affluent country in 1947, with per capita availability of renewable water at more than 5,000 cubic meters, to the verge of becoming water stressed, with per capita availability down to almost 1,000 cubic meters. Mainly due to an explosive growth in population that now stands at an estimated 190 million people. “Nobody in this country is doing anything to slow down the rate of population growth,” complained Shafqat Kakakhel, a former ambassador who has worked extensively on water related issues. “All other countries that were notorious for high population growth rates, Bangladesh, Subsaharan Africa, have done something ... we are doing absolutely nothing.”
More than 90 percent of Pakistan’s water resources are used in agriculture, which is much higher than the global average of 70 percent. The high consumption of water is blamed on outdated irrigation systems, loss of water during transmission, and the choice of crops.
Wrong choices
Pakistan mainly grows wheat, rice and sugar cane, which are all water intensive and some say the wrong choice for its agrarian economy. “There is absolutely no justification in Pakistan for sugarcane,” according to Kakakhel. “Sugarcane is like growing trees, like growing a forest, in the amount of water it consumes. And the rate of recovery, the amount of sugar you get from a litre of sugarcane juice is the lowest in the world.”
Another water and energy expert Arshad Abbasi insisted Pakistan’s problem is less of resources and more of management of resources. “More than 86 countries of the world are surviving on less water than us,” he said. They are doing so through efficient water management as well as modernizing their agriculture, he added. “Over the next 10 years, the way the crops are becoming hybrid internationally, our farmers will not be able to compete,” he cautioned. Giving an example of Indian Punjab, with topography similar to Pakistani Punjab, Abbasi explains Indian agricultural yield was two to three times higher than Pakistan.
Outdated infrastructure
Graphene-oxide Membranes Could Make Seawater Into Freshwater
April 03, 2017 - A new method could turn seawater into drinking water for millions around the world without access to clean water.
Researchers at the University of Manchester in England say they’ve successfully used graphene-oxide membranes to filter common salts from seawater, turning it into drinking water more affordably than current desalination techniques.
Graphene-oxide membranes have already been shown to be effective at filtering small nanoparticles, organic molecules and large salts, but they had not yet been effective in filtering out common salts. "This is the first clear-cut experiment in this regime,” said professor Rahul Nair, at the University of Manchester. “We also demonstrate that there are realistic possibilities to scale up the described approach and mass produce graphene-based membranes with required sieve sizes. “Realization of scalable membranes with uniform pore size down to atomic scale is a significant step forward and will open new possibilities for improving the efficiency of desalination technology,” he said.
An Indian ragpicker boy drinks water from a tap at an automobile yard on the outskirts of Jammu, India
The United Nations says that by 2025, 14 percent of the world’s population will suffer water scarcity. Previous attempts to use the membranes saw smaller salts passing through, researchers said, but the Manchester group discovered that the size of the pores on the membrane could be “precisely controlled” allowing it to block smaller salts.
Specifically, the researchers said the graphene-oxide membranes have tiny capillaries that stop the flow of salts, while allowing fresh water to pass through. "The developed membranes are not only useful for desalination, but the atomic scale tunability of the pore size also opens new opportunity to fabricate membranes with on-demand filtration capable of filtering out ions according to their sizes," said co-lead author Jijo Abraham. The study was published Monday in the journal Nature Nanotechnology.
http://www.voanews.com/a/mht-graphne...r/3794335.html
Last edited by waltky; 04-03-2017 at 04:34 PM.
Progress in desalination for a thirsty world...
Graphene sieve could make seawater drinkable
Tue April 4, 2017 - Researchers in the United Kingdom have developed a graphene-based sieve that can filter salt out of seawater, a development that could provide drinking water to millions of people around the globe.
See also:The applications could be a game-changer in countries where access to safe, clean, drinkable water is severely limited. Graphene -- an ultra-thin sheet of carbon atoms organized in a hexagonal lattice -- was first identified at the University of Manchester in 2002 and has since been hailed as a "wonder material," with scientists racing to develop inexpensive graphene-based barriers for desalination on an industrial scale. Now, the team at Manchester has used a compound of graphene, known as graphene oxide, to create a rigid sieve that could filter out salt using less energy.
Overcoming hurdles
In recent years, there had been some success in water filtration using graphene oxide to sift out other smaller nanoparticles and organic molecules But researchers had struggled to move forward after finding that the membrane's pores would swell up when immersed in water, allowing particles to continue to pass through. Rahul Nair's team at Manchester now claims it has discovered how to control of the expansion and size of the pores.
Writing Monday in the Nature Nanotechnology journal, the team revealed it was able to restrict pore-swelling by coating the material with epoxy resin composite that prevented the sieve from expanding. This means common salt crystals could continue to be filtered out, while leaving behind uncontaminated, clean, drinking water. The discovery is "a significant step forward and will open new possibilities for improving the efficiency of desalination technology," Nair said in a statement from the university. "This is the first clear-cut experiment in this regime. We also demonstrate that there are realistic possibilities to scale up the described approach and mass produce graphene-based membranes with required sieve sizes," he added.
Global implications
Boosting global access to water is critical. By 2025, 14% of the global population will suffer from water scarcity, the United Nations predicts. In addition, climate change is expected to wreak havoc on urban water supplies, with decreased rainfall and rising temperatures expected to fuel demand. Cities have been investing heavily in diversifying their water supplies, including developing new desalination technologies to make seawater potable. But existing, industrial-scale desalination plants can be costly and normally involve one of two methods: distillation through thermal energy, or filtration of salt from water using polymer-based membranes.
These techniques have drawn criticism from environmentalists, who argue they involve large amounts of energy, produce greenhouse gases and can be harm marine organisms.
What's next?
The graphene-oxide breakthrough has been welcomed by scientists in the field as a promising development, but some are cautious of the next steps. "The selective separation of water molecules from ions by physical restriction of interlayer spacing opens the door to the synthesis of inexpensive membranes for desalination," wrote Ram Devanathan of the Pacific Northwest National Laboratory, in an accompanying news-and-views article in the journal. More work still needs to be done to test the durability of the barriers and to confirm the membrane is resistant to "fouling by organics, salt and biological material," he said. Water treatment with membranes that separate water molecules from ions, pathogens and pollutants has been proposed as an energy-efficient solution to the freshwater crisis, Devanathan added. "The ultimate goal is to create a filtration device that will produce potable water from seawater or waste water with minimal energy input."
http://www.cnn.com/2017/04/04/health...ter/index.html
How oceans can solve our freshwater crisis
Mon May 26, 2014 - There are 16,000 desalination plants on the planet, and their numbers are rising; A huge desalination plant is under construction in Carlsbad, California; When completed it will be the largest such facility in the Western Hemisphere; Water expert: Ocean water is "a seemingly inexhaustible supply"
It's been a cruel irony for ancient mariners and any thirsty person who has ever gazed upon a sparkling blue ocean: Water, water everywhere, and not a drop to drink. But imagine a coastal city of the future, say in 2035. Along with basic infrastructure such as a port, roads, sewer lines and an electrical grid, it's increasingly likely this city by the sea will contain a newer feature.
A desalination plant.
Thanks to improved technology, turning ocean water into freshwater is becoming more economically feasible. And a looming global water crisis may make it crucial to the planet's future. The United Nations predicts that by 2025, two-thirds of the world's population will suffer water shortages, especially in the developing world and the parched Middle East. Scientists say climate change is making the problem worse. Even in the United States, demand for water in drought-ravaged California and the desert Southwest is outpacing supply. This is why a huge desalination plant is under construction in Carlsbad, California, some 30 miles north of San Diego. When completed in 2016, it will be the largest such facility in the Western Hemisphere and create 50 million gallons of freshwater a day.
"Whenever a drought exacerbates freshwater supplies in California, people tend to look toward the ocean for an answer," said Jennifer Bowles, executive director of the California-based Water Education Foundation. "It is, after all, a seemingly inexhaustible supply."
A growing trend
Most desalination technology follows one of two methods: distillation through thermal energy or the use of membranes to filter salt from water.
In the distillation process, saltwater is heated to produce water vapor, which is then condensed and collected as freshwater. The other method employs reverse osmosis to pump seawater through semi-permeable membranes -- paper-like filters with microscopic holes -- that trap the salt while allowing freshwater molecules to pass through. The remaining salty water is then pumped back into the ocean. Officials at the Carlsbad plant say they can covert two gallons of seawater into one gallon of freshwater by filtering out 99.9% of the salt. There are some 16,000 desalination plants on the planet, and their numbers are rising. The amount of desalted water produced around the world has more than tripled since 2000, according to the Center for Inland Desalination Systems at the University of Texas at El Paso. "Desalination is growing in arid regions," said Tom Davis, director of the center. "We are making progress in the USA, but the countries around the Persian Gulf are way ahead in the use of desalination, primarily because they have no alternative supplies of freshwater."
Israel, in an arid region with a coastline on the Mediterranean, meets half its freshwater needs through desalination. Australia, Algeria, Oman, Saudi Arabia and the United Arab Emirates also rely heavily on the ocean for their municipal water. In the United States, desalination projects are concentrated in coastal states such as California, Florida and Texas.
Some environmentalists are wary of desalination, which consumes large amounts of energy, produces greenhouse gases and kills vital marine organisms that are sucked into intake pipes. But proponents believe the technology offers a long-term, sustainable solution to the globe's water shortages. One entrepreneur has even built an experimental solar desalination plant in California's San Joaquin Valley. "When other freshwater sources are depleted, desalination will be our best choice," said Davis, a UTEP professor of engineering.
California dreaming
Call your state legislators and insist they approve the Article V convention of States to propose amendments.
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