Turning seawater into drinking water just became more feasible. Scientists at the University of Manchester in the UK have developed graphene oxide membranes with holes small enough to filter out salt. The sieves represent a technological breakthrough in the effort to make desalination more efficient and affordable.
Graphene oxide membranes have been used in desalination experiments for years, but never before has the sieve been small enough to filter out smaller particles.
One of the major challenges with this process is the natural tendency of graphene oxide membranes to swell in water. This causes their pores to expand, and salt particles to pass through. The scientists, led by Rahul Nair, were able to control the swelling by building epoxy resin walls around the membranes, as noted in the study published in Nature Nanotechnology.
"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," Nair said. "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."
According to the International Water Association, thousands of desalination plants currently exist worldwide, but the process remains expensive.
Earth's oceans contain 97 percent of the planet's water, the National Ocean Service estimates. To paint a picture of the total amount of salt in the oceans, NOAA said that "if the salt in the ocean could be removed and spread evenly over the Earth's land surface, it would form a layer more than 500 feet thick, about the height of a 40-story office building."
According to a United Nations report:
• Around 700 million people in 43 countries suffer today from water scarcity.
• By 2025, 1.8 billion people will be living in countries or regions with absolute water scarcity, and two-thirds of the world's population could be living under water stressed conditions.
• With climate change, almost half the world's population will be living in areas of high water stress by 2030.
In an article accompanying the scientists' research, Ram Devanathan, from the Pacific Northwest National Laboratory, said the next step toward scaling the desalination process would be to test the durability of the graphene oxide membranes.
"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," Devanathan said. "The ultimate goal is to create a filtration device that will produce potable water from seawater or wastewater with minimal energy input."
North Carolina-based startup EcoH2O Innovations has created the first-ever desalination buoy that only uses the power of waves to turn seawater into drinking water.
Engineers Justin Sonnett and Chris Matthews claim that a single Swell Actuated Reverse Osmosis System (SAROS) machine can clean 3,500 gallons of seawater a day. A grouping of 10-20 units can provide up to 50,000 gallons per site.
According to CityLab, the SAROS "draws in sea water, pumps it at high pressure through a reverse-osmosis membrane, and emits clean, drinkable water, which it stores in a tank until it's ready to be run back to shore."
Desalination plants are a potential solution for water scarcity but they have several problems—they require a large swath of land and city infrastructure, have a big brine discharge problem and also require fossil fuels to operate. The portable SAROS, however, can fit in the back of a truck only needs waves to run, making it relatively cost-effective and energy independent.
"SAROS is different because, by using it, we can cut the cost currently associated with producing fresh water in half," Matthews, SAROS director of research and development, told New Atlas.
The system was designed for the 230 million people living on island and coastal communities that lack access to potable water.
"Typical desalination processes can be taxing on the environment, especially coastal communities," the team said. "Unlike traditional methods that require a huge amount of power, typically generated by burning fuel oil, SAROS uses clean, renewable wave energy and produces zero emissions and minimal salt brine concentration."
Besides providing a constant source of clean water, the SAROS can help island nations curb their use of dirty energy. Many of these areas are bearing the brunt of climate change, from natural disasters to sea level rise.
"We're completely removing the dependency on electricity and fossil fuels, and creating one of the first environmentally conscious desalination systems that will allow us to bring affordable fresh water to coastal areas across the globe," the team added.
#Problem: 233 million people living in coastal regions & #islands don't have access to #CleanWater. #Answer: SAROS.… https://t.co/GVR68i2LLd— SAROS Desalination (@SAROS Desalination)1477331671.0
EcoH2O said the SAROS can one day be used to tackle other problems besides water scarcity.
"The innovative, wave-powered technology used in SAROS could also be configured to do things like generate electricity, autonomously pump water to clean up oil spills or even filter plastic from our ocean," the team said. "The amount of potential good that SAROS can bring is as exciting as it is endless."
Sonnett and Matthews came up with SAROS as their senior design project at the University of North Carolina at Charlotte in 2014. After graduating, they've picked up multiple awards for their concept, including the prestigious Thomas Edison Award in 2014 for dedication to sustainability.
The SAROS team has launched an Indiegogo crowdfunding campaign to raise the $25,000 they need to take this project above water. The cost per unit is expected to retail around $23,000.
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The bright patterns and recognizable designs of Waterlust's activewear aren't just for show. In fact, they're meant to promote the conversation around sustainability and give back to the ocean science and conservation community.
Each design is paired with a research lab, nonprofit, or education organization that has high intellectual merit and the potential to move the needle in its respective field. For each product sold, Waterlust donates 10% of profits to these conservation partners.
Eye-Catching Designs Made from Recycled Plastic Bottles
waterlust.com / @abamabam
The company sells a range of eco-friendly items like leggings, rash guards, and board shorts that are made using recycled post-consumer plastic bottles. There are currently 16 causes represented by distinct marine-life patterns, from whale shark research and invasive lionfish removal to sockeye salmon monitoring and abalone restoration.
One such organization is Get Inspired, a nonprofit that specializes in ocean restoration and environmental education. Get Inspired founder, marine biologist Nancy Caruso, says supporting on-the-ground efforts is one thing that sets Waterlust apart, like their apparel line that supports Get Inspired abalone restoration programs.
"All of us [conservation partners] are doing something," Caruso said. "We're not putting up exhibits and talking about it — although that is important — we're in the field."
Waterlust not only helps its conservation partners financially so they can continue their important work. It also helps them get the word out about what they're doing, whether that's through social media spotlights, photo and video projects, or the informative note card that comes with each piece of apparel.
"They're doing their part for sure, pushing the information out across all of their channels, and I think that's what makes them so interesting," Caruso said.
And then there are the clothes, which speak for themselves.
Advocate Apparel to Start Conversations About Conservation
waterlust.com / @oceanraysphotography
Waterlust's concept of "advocate apparel" encourages people to see getting dressed every day as an opportunity to not only express their individuality and style, but also to advance the conversation around marine science. By infusing science into clothing, people can visually represent species and ecosystems in need of advocacy — something that, more often than not, leads to a teaching moment.
"When people wear Waterlust gear, it's just a matter of time before somebody asks them about the bright, funky designs," said Waterlust's CEO, Patrick Rynne. "That moment is incredibly special, because it creates an intimate opportunity for the wearer to share what they've learned with another."
The idea for the company came to Rynne when he was a Ph.D. student in marine science.
"I was surrounded by incredible people that were discovering fascinating things but noticed that often their work wasn't reaching the general public in creative and engaging ways," he said. "That seemed like a missed opportunity with big implications."
Waterlust initially focused on conventional media, like film and photography, to promote ocean science, but the team quickly realized engagement on social media didn't translate to action or even knowledge sharing offscreen.
Rynne also saw the "in one ear, out the other" issue in the classroom — if students didn't repeatedly engage with the topics they learned, they'd quickly forget them.
"We decided that if we truly wanted to achieve our goal of bringing science into people's lives and have it stick, it would need to be through a process that is frequently repeated, fun, and functional," Rynne said. "That's when we thought about clothing."
Support Marine Research and Sustainability in Style
To date, Waterlust has sold tens of thousands of pieces of apparel in over 100 countries, and the interactions its products have sparked have had clear implications for furthering science communication.
For Caruso alone, it's led to opportunities to share her abalone restoration methods with communities far and wide.
"It moves my small little world of what I'm doing here in Orange County, California, across the entire globe," she said. "That's one of the beautiful things about our partnership."
Check out all of the different eco-conscious apparel options available from Waterlust to help promote ocean conservation.
Melissa Smith is an avid writer, scuba diver, backpacker, and all-around outdoor enthusiast. She graduated from the University of Florida with degrees in journalism and sustainable studies. Before joining EcoWatch, Melissa worked as the managing editor of Scuba Diving magazine and the communications manager of The Ocean Agency, a non-profit that's featured in the Emmy award-winning documentary Chasing Coral.
Sundrop Farms, a tomato production facility that is the first agricultural system of its kind in the world, celebrated its grand opening in Port Augusta, South Australia, Thursday.
Instead of soil, pesticides, fossil fuels and groundwater, Sundrop Farms uses only solar power and desalinated seawater to grow tomatoes across 49 acres. The water is pumped into the facility from the Spencer Gulf about 1.2 miles away where it is desalinated to water the farm's 180,000 tomato plants.
Screenshot from Sundrop Farms Vimeo video.
"The farm's solar power is generated by 23,000 mirrors that reflect sunlight towards a 115-meter (377-foot) high receiver tower. On a sunny day, up to 39 megawatts of energy can be produced—enough to power the desalination plant and supply the greenhouse's electricity needs," NewsScientist explained.
Graphic showing how the tower works to power the desalination plant.Screenshot from Sundrop Farms Vimeo video.
"We knew that considering the increase in population that we had to address the food shortage, the water shortage, the energy shortage," Reinier Wolterbeek, chief technical officer at Sundrop Farms, said.
This process helps work around the area's desert climate that is unsuitable for conventional farming. Seawater-soaked cardboard keeps the plants cool enough to stay healthy during the hot months, and solar heating keeps the greenhouse warm during the winter months. The seawater helps sterilize the air and the plants are grown in coconut husks allowing them to thrive without the use of pesticides.
RenewEconomy reports the farm will produce more than 118 million gallons of freshwater each year, the equivalent of 180 Olympic size swimming pools, and displace the use of more than 2 million liters of diesel a year.
"This state-of-the-art development is a massive boost for Port Augusta and the Upper Spencer Gulf, creating almost 200 jobs and heralding the start of an exciting new industry for the region," South Australia Premier Jay Weatherill said. "It also aligns with several of South Australia's key economic priorities, including creating premium food and wine from our clean environment and growth through innovation."
An honour opening the $200m @SundropFarms #solar desalination plant in Port Augusta today. Superb example of SA's l… https://t.co/5dqhrgPLkB— Jay Weatherill (@Jay Weatherill)1475724486.0
The farm expects to produce 17,000 metric tons—37,000 pounds of tomatoes—every year, about 13 percent of Australia's market share, and will be sold at a fixed price for 10 years exclusively at Coles Supermarkets.
"Because we do everything in a controlled environment, we know what our input costs are, and we're doing everything on a renewable basis, we can provide real consistency of supply and a higher quality product at a better price year 'round," Philipp Saumweber, chairman and CEO of Sundrop Farms, said.
Saumweber explained that with extreme weather events making it difficult to consistently provide consumers with products, Coles would at times find themselves without quality product, or without any product, and the two partnered to find a solution.
One of those solutions was already put to the test last week during a once-in-50-year storm that wreaked havoc in South Australia. Sundrop Farms was able to take the brunt of high winds and continue operations despite a massive blackout that crippled Whyalla steelworks and shut down the mines of mining giants BHP Billiton and OZ Minerals in northern South Australia.
Port Augusta mayor Sam Johnson told AFR that while there had been significant financial losses to businesses and households from the blackout in the regional city, Sundrop Farms is "living proof" that its groundbreaking technology could work on a large scale.
Sundrop is planning to launch similar sustainable greenhouses in Portugal and the U.S., and another in Australia.
Watch more on Sundrop Farms here:
Seawater desalination with nothing more than a small electrical field? A simple new method of creating freshwater from seawater—that uses far less energy than conventional methods do—has just been developed by researchers at the University of Texas at Austin and the University of Marburg in Germany.
A prototype "water chip" developed by researchers at The University of Texas at Austin in collaboration with a startup company. Photo Credit: University of Texas at Austin
The new method—electrochemically mediated seawater desalination—uses no membranes, is considerably simpler than conventional methods, and is so low-energy that it can be performed with the energy provided by store-bought batteries. Those are big improvements on all fronts—if the process can be adequately scaled up, it's a potentially revolutionary development. Freshwater scarcity is expected to become a significant problem in many regions of the world in the coming decades, but as it stands now, saltwater desalination isn't particularly economical ... A cheaper, simpler method than those currently available would be of great use—one which could be used on larger scales than simple solar stills are.
The new method/technology is patent-pending and is currently in commercial development by startup company Okeanos Technologies.
“The availability of water for drinking and crop irrigation is one of the most basic requirements for maintaining and improving human health," said Richard Crooks of The University of Texas at Austin. “Seawater desalination is one way to address this need, but most current methods for desalinating water rely on expensive and easily contaminated membranes. The membrane-free method we've developed still needs to be refined and scaled up, but if we can succeed at that, then one day it might be possible to provide fresh water on a massive scale using a simple, even portable, system."
The researchers think that the new method could be of particular use to those in the world's poorer, more water-stressed regions—more than a third of the world's people live in such regions. While lacking in freshwater, the majority of these regions have access to vast seawater resources, just not an economical means to desalinate it.
“People are dying because of a lack of freshwater," said Tony Frudakis, founder and CEO of Okeanos Technologies. “And they'll continue to do so until there is some kind of breakthrough, and that is what we are hoping our technology will represent."
The University of Texas at Austin explains the method:
To achieve desalination, the researchers apply a small voltage (3.0 volts) to a plastic chip filled with seawater. The chip contains a microchannel with two branches. At the junction of the channel an embedded electrode neutralizes some of the chloride ions in seawater to create an “ion depletion zone" that increases the local electric field compared with the rest of the channel. This change in the electric field is sufficient to redirect salts into one branch, allowing desalinated water to pass through the other branch.
“The neutralization reaction occurring at the electrode is key to removing the salts in seawater," stated Kyle Knust, a graduate student and co-author on the new research paper.
“Like a troll at the foot of the bridge, the ion depletion zone prevents salt from passing through, resulting in the production of freshwater."
As of now, the best that the researchers have achieved is 25 percent desalination—drinking water requires 99 percent desalination. The researchers are confident, though, that the 99 percent goal is very achievable.
“This was a proof of principle," stated Knust. “We've made comparable performance improvements while developing other applications based on the formation of an ion depletion zone. That suggests that 99 percent desalination is not beyond our reach."
The process will also need to be scaled up—as of right now, the microchannels are about the size of a human hair, and produce about 40 nanoliters of desalted water per minute. In order for the technology to be of practical use, a device would have to produce several liters—at least—of water per day.
The researchers are confident that this can be achieved, creating “a future in which the technology is deployed at different scales to meet different needs."
“You could build a disaster relief array or a municipal-scale unit," said Frudakis. “Okeanos has even contemplated building a small system that would look like a Coke machine and would operate in a standalone fashion to produce enough water for a small village."
The new research was just published in the journal Angewandte Chemie.
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