Nearly 80 percent of disease in developing countries is linked to bad water and sanitation; now scientists have developed a simple, cheap way to make water safe to drink, even if it is muddy
Nearly 80 percent of disease in developing countries is linked to bad water and sanitation. Now a scientist at Michigan Technological University has developed a simple, cheap way to make water safe to drink, even if it is muddy.
It is easy enough to purify clear water. The solar water disinfection method, or SODIS, calls for leaving a transparent plastic bottle of clear water out in the sun for six hours. That allows heat and ultraviolet radiation to wipe out most pathogens that cause diarrhea, a malady that kills 4,000 children a day in Africa.
It is a different story if the water is murky, as it often is where people must fetch water from rivers, streams, and boreholes. “In the developing world, many people don’t have access to clear water, and it’s very hard to get rid of the suspended clay particles,” says Joshua Pearce, an associate professor of materials science and engineering. “But if you don’t, SODISdoesn’t work. The microorganisms hide under the clay and avoid the UV.”
To purify your water, you first have to get the clay to settle out, a process called flocculation. A Michigan Technological University release reportsthat Pearce, working with student Brittney Dawney of Queen’s Universityin Ontario, discovered that one of the most abundant minerals on Earth does this job very well: sodium chloride, or simple table salt.
Salt is inexpensive and available almost everywhere. And it doesn’t take very much to make muddy water clear again.
“The water has a lower sodium concentration than Gatorade,” Pearce says. This would still be too much salt to pass muster as American tap water, but American tap water is not the alternative.
“I’ve drunk this water myself. If I were somewhere with no clean water and had kids with diarrhea, and this could save their lives, I’d use this, no question,” he says.
Salt works best when the suspended particles are a type of clay called bentonite. The technique doesn’t work as well with other kinds of clay. However, by adding a little bentonite with the salt to water containing these different clays, most of the particles glom together and settle out, creating water clear enough for SODIS treatment.
Pearce and Dawney are running more tests on water containing various types of clays, and they are also investigating different soil types across Africa to see where their methods might work the best.
— Read more in “Optimizing the Solar Water Disinfection (SODIS) Method by Decreasing Turbidity with NaCl,” Journal of Water, Sanitation, and Hygiene for Development (forthcoming, June 2012)
Eolewater’s WMS1000 wind-driven water-harvesting system uses on-board cooling units to chill the air until its moisture condenses
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We’ve all seen ice cold glasses and bottles dripping with condensation after cooling water vapor in the air, and though grabbing water out of thin air is not new, it took French inventor and Eolewater founder Marc Parent’s umpteenth emptying of his air conditioner’s condensate to envision harvesting atmospheric moisture on acommercial scale using wind turbines. After years of designs and prototypes, his proof-of-concept device, essentially a wind-powered refrigeration/condensation/filtration unit, was put in operation in the dry desert air of Abu Dhabi last October where it’s been reliably extracting 130-200 gal (approx. 500-800L) of clean, fresh water a day ever since.
“Access to drinking water is a condition for life and cannot be considered a luxury reserved to developed countries,” Parent said. “Humanity cannot ignore the pain of those deprived of water access and has to find new solutions.” The turbine units are not designed solely for desert-use. Being self-contained makes them suitable for any isolated areas that lack the infrastructure for water and/or electricity distribution, including islands, disaster areas, etc.
Housed in a 19.7 ft x 6.5 ft (6 m x 2 m) nacelle, Eolewater’s fifth generation WMS1000 water condenser system sits atop a 78 ft (24m) mast and is powered by a 30 kW wind turbine (minimum 15 mph (24 kph) wind speed required) with a 42 ft (13 m) diameter rotor. Since our atmosphere contains a reasonable amount of water (even the Sahara desert has an average relative humidity of around 25%), it’s simply a matter of using the wind to generate electricity for the on-board cooling units to chill the air until its moisture condenses out.
Once the water is collected, it is filtered and sent to stainless steel tanks for storage – simple as that. Apparently, the units are so durably built that, with routine maintenance, it’s estimated they’ll last up to 30 years. In areas where sun abounds but the winds are unreliable, Eole has also designed the WMS-30kW Solar Panel to drive the condensation/filtration equipment. For the millions living in or adjacent to deserts and drought-prone areas around the world, that’s welcome news, indeed.
Source: Simbol Materials
Simbol Materials and Geothermal Plant site at Salton Sea region, Ca.
Pleasanton-based Simbol Materials’technology can pull lithium, and other critical metals, out of the effluent water of some geothermal power plants, eliminating the drill-and-blast approach of traditional mining.
“Geothermal power plants provide a quality source of brine,” says Simbol CEO Luka Erceg. “It’s replete and rich with lithium and other metals” like zinc and manganese, he adds.
That’s because geothermal power plants extract hot brine or steam from underground to turn turbines and generate power.
Simbol’s focus will be on the geothermal power plants around the Salton Sea in California’s Imperial Valley.
The economics are compelling, says Erceg, noting that the Salton Sea is capable of supporting 500-600MW of geothermal power generation.
Just one “typical” 50MW plant, he says, creates enough brine to produce 16,000 tons of lithium carbonate — a key form of the element — as well as significant amounts of zinc and manganese.
Market rates for lithium carbonate are currently around $5,500/ton.
The Simbol process leverages a current business to get raw “ore” for almost nothing, something conventional miners pay a fortune to find and exploit.
“We’re at the tail end of their process,” says Simbol’s Erceg. “The last thing I want to do is build a geothermal power plant” just to access the brine, he says.
The power plant owners receive a royalty, he says, adding that geothermal power plant operator EnergySource is a Simbol partner.
“It’s great for geothermal [power plant] owners whose plants’ effluent contains sufficient lithium,” says Garvin Jabusch, chief investment officer at investment firm Green Alpha Advisors. “It means they now have two revenue streams from the same operations — a dream scenario.”
He adds that for geothermal projects with the right geology “this could be a game-changer and allow the net cost of their power to compete with fossil fuels.”
Global demand for lithium is expected to jump to nearly 300,000 tons annually by 2020, according to several clean tech research firms, driven by a need for electric vehicle batteries.
The remaining 75 percent is used by various industries, from pharmaceuticals to ceramics.
Erceg says his goal is to be “among the lowest cost producers” of lithium, which industry estimates put at between $1450-2500/ton.
But Green Alpha’s Jabusch says the booming worldwide need for lithium-ion rechargeable batteries — for consumer electronics and tools as well as electric and hybrid vehicles — actually points to a current shortage.
“Considering the global economy is experiencing about a 35,000-ton annual lithium shortfall, there will be no problem [for Simbol to] find markets and still get competitive prices,” says Jabusch.
Unlike a typical mining process that produces tailings that require remediation, Erceg says their process actually better prepares the brine for re-injection into the geothermal source, where it would normally be sent anyway.
For power plant operators, a new revenue stream is more good news, considering geothermal energy is already among the cheapest fuel sources.
US Department of Energy figures show that for plants commissioned by 2016, the levelized cost of energy for geothermal is about $102/mwh, compared to $109/mwh for advanced coal-fired plants and $113/mwh for next-generation nuclear power.
But like solar and wind power, while the fuel is effectively free, the upfront capital costs can be high.
Investor presentations at various renewable energy conferences have shown drilling of geothermal wells, each capable of producing around 5MW of power, cost around $10 million, with a 20 percent failure rate.
For Erceg, he says one issue, as with all drilling, is the government permitting process.
“There’s no way to be innovative around those delays,” he says.
That could help more power plants using Simbol’s technology, says Green Alpha’s Jabusch.But previously tabled legislation in the US Congress could be pointing to coming incentives for domestic production of critical materials, like lithium, in the near future.
Concerns over China’s hoarding of rare earth metals in past years — metals critical to the clean tech industry — led the US Department of Energy to produce a 2011 report identifying critical metals to the US cleantech industry, including lithium.
“I think given the importance of lithium [in] batteries, magnets, turbines, and their importance in the next green economy, that the most key, rarest ones should absolutely be declared ‘critical,’” says Jabusch. “Clearly they’re already critical to China, which has taken a lead to the tune something like 80 percent of Earth’s existing production.”
Whatever the demand for lithium and other critical metals, Simbol’s approach is also a sign of a growing movement towards “clean mining” techniques that also improve the miner’s bottom line, says clean tech analyst Dallas Kachan, managing director at research firm Kachan and Co.
“The world has had hundreds of years of dirty mining,” he says. “It’s taking time for new clean technologies that are quietly emerging to prove themselves economically.”
But Kachan, whose firm is spearheading the creation of a new clean mining trade group, adds that advances in energy savings, waste stream reuse and better site reclamation are changing the entire mining industry for the better.
“You’ll soon start to see them reshape the face of mining as we know it today,” he says.
“We need these elements and lots of them,” says Green Alpha’s Jabusch. “To the extent that Simbol or any other enterprise can get them from existing drilling operations, so much the better.”
Florence eager to discuss copper mine
Council moves ahead despite firm’s delay
2 comments by Ryan Randazzo – Oct. 27, 2011 12:00 AM
The Arizona Republic
The town of Florence is not letting Curis Resources Ltd. off the hook, announcing that the Town Council will address the issue of the Canadian company’s plans to mine copper in town even though the proposal was withdrawn.
Curis officials last week withdrew their request for zoning changes needed from the town to proceed with their full mine, although the company says part of the mine can be developed on state land without the town’s approval.
But the Town Council issued a press statement declaring it will take a public vote on whether to accept that withdrawal, and if the members reject the withdrawal, they can vote on whether or not to grant the zoning changes the mine needs.
“This is the direction of the entire council,” deputy town manager and spokesman Jess Knudson said. “Essentially it is a reaction to Curis pulling the application two years in a row. It’s been a pretty big deal. There are a lot of folks in town who feel strongly one way or another.”
Knudson said about 300 people showed up to one Planning and Zoning Commission meeting and about 275 to another when the mine was discussed.
At the last meeting, the commission, which advises the Town Council, rejected one of the mining company’s applications and deadlocked on another.
Curis officials said they would withdraw their application until they get the needed environmental approvals from the state and Environmental Protection Agency, which could put the town more at ease.
But Knudson said the town leaders want to address the issue, not wait.
“It is something that is very closely looked at and a highly debated topic in the community,” he said. “This is not so much a reaction to Curis as it is the council wanting to speak out on the project.”
The council will meet at 6 p.m. Nov. 7 at Florence High School. The meeting will be broadcast live online.
The officials will first vote whether to accept the withdrawal, and if they reject that, they will address the zoning changes.
If the meeting runs long, they plan to recess at 11 p.m. and reconvene the next night at the same place.
Curis plans to use a process called “in-situ” copper recovery, which involves pumping acid underground to collect copper, sucking it back to the surface and processing the copper from it.
Nearby landowners and town residents have fought the plans because they worry that pumping acid underground would pollute the area’s drinking water.
India’s water desalination business is set to triple to $1.2 billion by 2017 as rising demand fromindustry spurs the South Asian country to build more purification plants, according to a research report.
The number of units that process sea water in India will reach 500 in five years from 180 now, with more than 300 plants being built in the states of Tamil Nadu, Gujarat and Maharashtra,TechSci Research said in its report. Saudi Arabia leads the global desalination market worth $14.3 billion, according to Karan Chechi, TechSci’s research director.
“Improved hybrid technologies and reverse osmosis have cut production costs and initial investment in water desalination industry compared with traditional methods,” Chechi said in a telephone interview from Noida, near New Delhi. “This is attracting investors.”
Indiscriminate sinking of wells by farmers is depleting ground water resources in the world’s second-most populous nation, prompting the government to spend about $1 billion for mapping aquifers. Desalination plants may help supply water for power producers, drug makers and others, said Chechi.
More than 85 percent of India’s villages and half of its cities rely on wells for water in the country where farming accounts for 90 percent of total water withdrawals. India allocated 536.6 billion rupees ($11 billion) for urban supply projects in the five years ending March 2012.
The market for desalination in India, which has a coastline of 7,517 kilometers (4,671 miles), may be worth $630 million by 2014, according to TechSci. Power plants and pharmaceutical companies use 72 percent of the current capacity, with the remainder taken up by municipal corporations, TechSci said.
To contact the reporter on this story: Archana Chaudhary in New Delhi firstname.lastname@example.org
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