There’s a buzz at the point where wastewater and energy meet—and the buzz phrase is “energy neutrality”. Hear it this week at the Ozwater conference, on any day at the University of Queensland Advanced Water Management Centre, in the offices of Melbourne Water and Yarra Valley Water… in Australian cities and country areas.
As populations increase, our demand for water is growing; as the flow of water in and water out stretches Australia’s environmental capacity, regulations are necessarily being tightened, requiring more intensive water processing; and all the time the electricity meter at the wastewater plant is ticking over, and over the top. Figures from UNESCO in 2015 estimate that electricity accounts for 40% of all operational costs in wastewater treatment.
As the price of electricity climbs and the need to reduce carbon emissions grows, Australia’s more than 700 community sewage treatment plants have begun seriously paddling towards energy neutrality—a state of operations in which they produce as much energy as they use.
And yes, our wastewater utilities, do have a paddle in this endeavour—an oarsome set of options—in the form of rapidly developing technologies that will both reduce electricity requirements and capture the energy generated through breaking down biosolids.
In fact, watch this space as new technologies transform water-treatment utilities from energy consumers to energy producers.
If energy neutrality is the buzz phrase of the moment, the core concept in turning the wastewater tide towards productivity is to view treatment plants not as waste-disposal facilities, but as resource-recovery plants, says Jeff Peeters, senior product manager at GE Water & Process Technologies. Based in Canada, Peeters is widely considered a thought leader in the field of water processing, and has turned a masters of engineering toward commercialising innovative water-treatment systems.
In a recent guest column, The future of energy-neutral wastewater treatment is here, for Water Online, he writes: “We all need water and energy, and we all need to take part in the efforts to secure them for generations to come. Water reuse, policies and partnerships, and emerging disruptive technology solutions are vital to the cause.”
One strategy used by wastewater facilities to achieve neutrality in their energy consumption is to produce energy onsite by harnessing renewables such as wind, solar and hydro power. But the real disruptor here is increasingly efficient technology for capturing and using energy generated by the very breakdown of biosolids (sewage sludge) and biowastes (household and commercial food wastes, fats, oils and grease) that treatment plants are contracted to carry out.
Advanced anaerobic digestion processes, such as that developed by GE’s Monsal, maximise biogas yields from waste and/or wastewater solids, delivering more energy than previous digestion systems, which were often deemed uneconomical. Peeters explains anaerobic digestion, in simple terms, as using “bacteria in the absence of oxygen to break down organic matter to create biogas. The biogas can then be combusted or oxidised and used for heating or with a gas engine to produce electricity and heat. It can also be compressed and used as fuel for vehicles or sold for use in a natural-gas grid.
“Consider this,” he continues: “A city of 500,000 people produces roughly 75,000 tons of household and commercial food waste and more than 14,000 tons of sewage sludge. By treating that waste with advanced anaerobic digestion, the value of the methane byproduct used in one of GE’s Jenbacher gas engines would produce about 5MWe of electricity alone—enough to power 10,000 homes.”
Smart city! One of the key themes of this month’s Ozwater conference has been Liveable and sustainable cities of the future, with speakers from Flinders University, Beca (engineering and project management), Sydney Water and Veolia (water, energy and waste management) posing recent findings and solutions to the wastewater-energy equation.
New technologies can transform treatment plants from energy customers to energy producers.
The infrastructure and logistical change required to swing a small city to processing combined biowaste and sewage sludge does require some capital outlay. But GE also has a focus on low-hanging-fruit approaches that can help utilities burdened with older infrastructure simultaneously switch down their power usage and switch up processing to meet increased demand.
In partnership with the Metro Water Reclamation District of Greater Chicago, Peeters is leading a GE team in carrying out large-scale testing of ZeeLung, GE’s latest water-treatment membrane technology.
Chicago’s Metro Water operates the Terrence J. O’Brien Water Reclamation Plant, one of the largest sewage-treatment plants in the US, which processes almost a billion litres of sewage each day. Says plant manager Sanjay Patel, “It takes a lot of energy to do what we do. My electric bill is about US$5 million a year. So anything we can do to cut back on that bill would not only help us, but also help the citizens who pay the taxes.”
ZeeLung membrane-aerated biofilm reactor (MABR) technology uses a quarter of the energy required by fine-bubble aeration, which is widely used to provide oxygen in activated sludge processing. ZeeLung improves on the process by transferring atmospheric air down the lumen of hollow fibre membranes; oxygen is then diffused through the membrane walls to a biofilm that grows on their outer surface. Microorganisms in the biofilm break down, or metabolise, the organic compounds in the sewage. Says Peeters, “ZeeLung addresses the largest energy consumer in wastewater-treatment plants: the aeration process, which is responsible for approximately 60% of energy used.”
In an interview with Treatment Plant Operator magazine last month, Peeters explained, “Until now, the game in aeration has been how to make smaller and smaller bubbles, because that increases the surface area of air in contact with the liquid. That has limitations in transfer efficiency, as typically 60% to 70% of the oxygen that goes into the basin comes out at the surface and isn’t used. With ZeeLung MABR, we use a membrane to diffuse oxygen directly into a biofilm.”
Unlike GE’s ZeeWeed membrane filtration systems, which famously protect Australia’s Great Barrier Reef from dirty-water outfalls, ZeeLung does not filter the water. Although it looks identical to ZeeWeed, its bundles of membrane fibres, deployed in cassettes and installed in the aeration tank are made of material “that has an affinity for diffusing oxygen”, says Peeters—“it’s a gas-transfer membrane”.
Importantly, ZeeLung cassettes can be installed in new plants or retrofitted to existing aeration tanks. In this way, it can upgrade space-constrained facilities to meet new regulatory requirements or expand their capacity without increasing their footprint.
For Sanjay Patel at the Terrence J. O’Brien plant, “The promise is that it would cut back on our aeration energy by about 40%. That’s a lot of money to gain!” And it will take the Chicago plant one large step closer to energy neutrality.
Enabling great leaps in energy reduction for utilities is at the heart of GE’s Energy Neutral water portfolio, which also includes LEAPprimary. This advanced primary wastewater treatment system combines separation, thickening and dewatering of primary solids in a compact unit that reduces the energy used in conventional biological treatment by 25%.
For wastewater-processing facilities, “energy efficiency has not historically been at the top of the list of priorities,” writes Peeters in Water Online. But, “Energy conservation, on-site generation and renewable energy are becoming increasingly important to wastewater utilities as energy policy, energy economics and actions to mitigate climate change converge with the need to meet higher standards of wastewater treatment… Emerging disruptive innovations in technology combined with operational best practices are bringing into focus the opportunity to achieve energy-neutral wastewater treatment.”
Something to spout about: QGC’s Northern Water Treatment Plant can take up to 100 million litres of brine a day, piped from the coal-seam-gas fields of Queensland and turn it into water that’s suitable for irrigation or industrial purposes in this rainfall-challenged region. Now the 2016 Global Water Awards has recognised the performance and innovative excellence of QGC’s water-recycling efforts in naming the Northern plant Industrial Water Project of the Year.
Water flowed freely to celebrate the win announced by Felipe Calderón, chairman of the Global Commission on the Economy and Climate, in the doubly dry city of Abu Dhabi this April. The prestigious awards, inaugurated in 2006, recognise initiatives that “are moving the industry forward through improved operating performance, innovative technology adoption and sustainable financial models”.
Commissioned in May 2015, the $550 million Northern Water Treatment project was delivered by an alliance between GE and Laing O’Rourke Australia. To satisfy the most stringent environmental regulations, it pumps the effluent of thousands of coal-seam-gas wells through four phases of GE advanced water-treatment technologies; the water running ever sweeter and clearer from its saline beginnings as it passes through ZeeWeed submerged ultrafiltration, ion-exchange, three-stage reverse osmosis (RO) and brine concentration.
“The reverse osmosis produces clean water, or permeate, but in order to maximise the recovery of water, the QGC plant includes brine concentrators,” says Mike Rees, regional commercial leader, GE Power & Water. Reverse osmosis results in some 90% recovery of clean water from the original brine; the concentrators increase that flow to around 97%.
“This is certainly water that would not otherwise be available,” says Rees of the output of three variously sized plants in the region, all constructed by QGC (part of the BG Group which was recently acquired by Royal Dutch Shell). “There are a number of agricultural enterprises which are taking full advantage of a more certain, constant supply of water.”
While the processes were designed to maximise water delivery, construction of the plant components was planned to minimise disruption to roads and communities in this remote region—it was largely carried out offsite. The pipe racks were designed to enable a “plug and play” installation sequence before being brought to the site by truck in carefully timed transport envelopes. The 120-tonne concentrators were manufactured in New Zealand, shipped “across the ditch” to Queensland, trucked overland, and installed using one of the largest mobile cranes in Australia.
QGC and other coal-seam-gas companies in the region supply the three massive liquefied natural gas (LNG) processing plants on Curtis Island just off Gladstone on the Queensland coast. This multibillion-dollar venture to produce LNG from coal-seam gas is a world first. Similarly, says Rees, “The treatment of coal-seam-gas-produced water on this large a scale is, we’re proud to say, also a world first.”
He says one of the major challenges in processing water produced in wells by CSG drilling is that unlike seawater or brackish water which is characterised by relatively consistent salt content, CSG water varies widely. “Over the life of the whole CSG-to-LNG project, they’ll be drilling thousands of wells in different gas fields, and from well to well the water volume and water quality can vary significantly. This plant needed to be capable of handling a wide range of of potential raw water quality and flow rates—it had to have enough flexibility to produce water of the required standard, no matter what the input, day in, day out.”
The Global Water Awards 2016 acknowledged public debate in Australia over coal-seam-gas produced water and concluded: “A practical, pragmatic solution such as this cuts through the rhetoric to the heart of the problem, enhancing QGC’s social licence to operate through its emphasis on responsible treatment and reuse.”
Top photo: QGC’s $550 million commitment to providing clean water from coal-seam gas mining has scored a 2016 Global Water Award: Industrial Water Project of the Year.
Climate-KIC, a European-union climate innovation initiative, recently selected a jury of entrepreneurs, financiers and business people to award funding to what they felt were Europe’s best clean-tech innovations of 2014. Taking first place was Dutch startup aQysta, a Delft University of Technology spin-off company that manufactures what’s known as the Barsha irrigation pump. It can reportedly boost crop yields in developing nations by up to five times, yet requires no fuel or electricity to operate.
Although the Barsha pump (Nepalese for “rain pump”) is a new product, it’s based on a very old design – it has its origins in ancient Egypt.
The pump itself is essentially a water wheel on a floating platform, that’s moored in a nearby flowing river. The moving water rotates the wheel, that in turn utilizes a spiral mechanism to compress air. That air drives water through an attached hose and up to the fields.
It’s claimed to be capable of pumping water up to a height of 25 meters (82 ft), at a maximum rate of one liter (0.26 US gal) per second. According to its designers, it has zero operating costs, only one moving part, can be built from locally-available materials, and should provide a return on investment within one year of use – for diesel-powered pumps, they claim that the figure is closer to 10 years.
Of course, it also creates no emissions.
The first Barsha pump was set up in Nepal this July, and a business is now being established there to manufacture and market the devices. Plans call for similar developments in Asia, Latin America, and Africa.
A sample of beryl and an illustration that shows the strange shape water molecules take when found in the mineral’s cage-like channels (Credit: ORNL/Jeff Scovil).
You already know that water can have three states of matter: solid, liquid and gas. But scientists at the Oak Ridge National Lab (ORNL) have discovered that when it’s put under extreme pressure in small spaces, the life-giving liquid can exhibit a strange fourth state known as tunneling.
The water under question was found in super-small six-sided channels in the mineral beryl, which forms the basis for the gems aquamarine and emerald. The channels measure only about five atoms across and function basically as cages that can each trap one water molecule. What the researchers found was that in this incredibly tight space, the water molecule exhibited a characteristic usually only seen at the much smaller quantum level, called tunneling.
Basically, quantum tunneling means that a particle, or in this case a molecule, can overcome a barrier and be on both sides of it at once – or anywhere between. Think of rolling a ball down one side of a hill and up another. The second hill is the barrier and the ball would only have enough energy to climb it to the height from which it was originally dropped. If the second hill was taller, the ball wouldn’t be able to roll over it. That’s classical physics. Quantum physics and the concept of tunneling means the ball could jump to the other side of the hill with ease or even be found inside the hill – or on both sides of the hill at once.
“In classical physics the atom cannot jump over a barrier if it does not have enough energy for this,” ORNL instrument scientist Alexander Kolesnikov tells Gizmag – Kolesnikov is lead author on a paper detailing the discovery published in the April 22 issue of the journal Physical Review Letters. But in the case of the beryl-trapped water his team studied, the water molecules acted according to quantum – not classical – laws of physics.
“This means that the oxygen and hydrogen atoms of the water molecule are ‘delocalized’ and therefore simultaneously present in all six symmetrically equivalent positions in the channel at the same time,” says Kolesnikov. “It’s one of those phenomena that only occur in quantum mechanics and has no parallel in our everyday experience.”
By using neutron-scattering experiments, the researchers were able to see that the water molecules spread themselves into two corrugated rings, one inside the other. At the center of the ring, the hydrogen atom, which is one third of the water molecule, took on six different orientations at one time. “Tunneling among these orientations means the hydrogen atom is not located at one position, but smeared out in a ring shape,” says a report in the online news journal Physics.
“This discovery represents a new fundamental understanding of the behavior of water and the way water utilizes energy,” says ORNL co-author Lawrence Anovitz. “It’s also interesting to think that those water molecules in your aquamarine or emerald ring – blue and green varieties of beryl – are undergoing the same quantum tunneling we’ve seen in our experiments.”
Because the ORNL team discovered this new property of water but not exactly why and how it works, Anovitz also says that the finding is sure to get scientists working to uncover the mechanism that leads to the phenomenon.
Kolesnikov adds that the discovery could have implications wherever water is found in extremely tight spaces such as in cell membranes or inside carbon nanotubes. The following video from ORNL provides more details on the discovery.
Polluted water can at times make swimming in the sea or a pool risky, on the other hand aquatic organisms such as water boatman need the nutrients in dirty water to feed on. Taking inspiration from water beetles and other swimming insects, academics at the Bristol Robotics Laboratory (BRL) have developed the Row-bot, a robot that thrives in dirty water. The Row-bot mimics the way that the water boatman moves and the way that it feeds on rich organic matter in the dirty water it swims in.
The Row-bot project aims to develop an autonomous swimming robot able to operate indefinitely in remote unstructured locations by scavenging its energy from the environment. When it is hungry the Row-bot opens its soft robotic mouth and rows forward to fill its microbial fuel cell (MFC) stomach with nutrient-rich dirty water. It then closes its mouth and slowly digests the nutrients. The MFC stomach uses the bio-degradation of organic matter to generate electricity using bio-inspired mechanisms. When it has recharged its electrical energy stores the Row-bot rows off to a new location, ready for another gulp of dirty water.
Jonathan Rossiter, Professor of Robotics at the University of Bristol and BRL, said: “The work shows a crucial step in the development of autonomous robots capable of long-term self-power. Most robots require re-charging or refuelling, often requiring human involvement.”
Hemma Philamore, PhD student, added: “We anticipate that the Row-bot will be used in environmental clean-up operations of contaminants, such as oil spills and harmful algal bloom, and in long term autonomous environmental monitoring of hazardous environments, for example those hit by natural and man-made disasters.”
The prototype robot combines two subsystems; a bioinspired energy source and bio-inspired actuation. The first subsystem shows the power generation capability of the robot. A second duplicate system starts the refuelling process and moves the robot with an energy requirement that is less than the energy generated by the first system. This is achieved by feeding on chemical energy contained in its surrounding fluid to support microbial metabolism inside the MFC.
Mimicking the water boatman’s feeding mechanism, which employs a broad beaklike mouth to sweep in both fluid and suspended particulate matter, the Row-bot feeds its MFC stomach by opening and closing the mouth-like orifice at each end of the MFC through the bending of a flexible acetate envelope structure. By using both these systems the robot can be totally independent in water providing enough energy is available in the fluid.
The Row-bot was developed at the Bristol Robotics Laboratory, a collaboration between the University of Bristol and UWE Bristol, by PhD student, Hemma Philamore and her PhD supervisors; Professor Jonathan Rossiter from the University of Bristol’s Department of Engineering Mathematics and Professor Ioannis Ieropoulos from the Bristol BioEnergy Centre at the University of the West of England.
Using specially synthesized crystalline materials, scientists from the University of Southern Denmark have created a substance that is able to absorb and store oxygen in such high concentrations that just one bucketful is enough to remove all of the oxygen in a room. The substance is also able to release the stored oxygen in a controlled manner when it is needed, so just a few grains could replace the need for divers to carry bulky scuba tanks.
The key component of the new material is the element cobalt, which is bound in a specially designed organic molecule. In standard form – and depending on the available oxygen content, the ambient temperature, and the barometric pressure – the absorption of oxygen by the material from its surroundings may take anything from seconds to days.
“An important aspect of this new material is that it does not react irreversibly with oxygen – even though it absorbs oxygen in a so-called selective chemisorptive process,” said Professor Christine McKenzie from the University of Southern Denmark. “The material is both a sensor, and a container for oxygen – we can use it to bind, store, and transport oxygen – like a solid artificial hemoglobin.”
The crystalline material changes color when absorbing or releasing oxygen: black when saturated, pink when oxygen released (Photo: University of Denmark)
Varying the constituent structure of the material can also bind and release oxygen at different rates. This means it could be used to regulate oxygen supply in fuel cells or create devices like face masks that use layers of the material to provide pure oxygen to a person directly from the air, without the need of other equipment.
Even more interestingly, the material may also be configured in a device that could absorb oxygen directly from water and allow a diver to stay submerged for long periods of time, without the need for bulky air tanks.
“This could be valuable for lung patients who today must carry heavy oxygen tanks with them,” explains Professor McKenzie. “But also divers may one day be able to leave the oxygen tanks at home and instead get oxygen from this material as it ‘filters’ and concentrates oxygen from surrounding air or water. A few grains contain enough oxygen for one breath, and as the material can absorb oxygen from the water around the diver and supply the diver with it, the diver will not need to bring more than these few grains.”
Using x-ray diffraction techniques to peer inside the atomic arrangement of the material when it had been filled with oxygen, the scientists realized that once the oxygen has been absorbed it can be stored in the material until it is released by heating the material gently or subjecting it to a vacuum.
“We see release of oxygen when we heat up the material, and we have also seen it when we apply vacuum,” said Professor McKenzie. “We are now wondering if light can also be used as a trigger for the material to release oxygen – this has prospects in the growing field of artificial photosynthesis.”
There’s no word as yet on any possible commercial production or public availability of the material.
The research was published in the journal of the Royal Society of Chemistry, Chemical Science.
After a day spent hiking, biking, climbing or otherwise exerting yourself outdoors, a shower sure feels nice. Climbing into your car and driving home all sweaty in order to take said shower, however, can be quite a drag. That’s why Colorado native Joel Cotton created the Road Shower. It’s a pressurized water tank that mounts on your roof rack, allowing you to grab a quick shower beside your car – just look out for Peeping Toms.
The tank is made from powder-coated aluminum, holds 5 gallons/19 liters of water (which Cotton says should be good for two to three showers), and can be mounted on Yakima, Thule and “most other” rack systems. While it sits up in the sunlight as you drive, its black paint job helps heat up the water contained within. Should that water get too hot, however, its radiator-style fill cap contains a release valve that allows steam to escape.
To use it, users first pressurize the tank by hooking a CO2 canister or a bike pump up to its air input valve. They they take the hose down from its clamps, and set the nozzle to one of its seven settings – these include shower, jet and mist. From there, they just take a shower. Presumably they start by placing an experimental fingertip in front of the nozzle, to check that the water isn’t too hot or too cold.
Because both the food-grade hose and the inside of the tank are non-toxic, Cotton points out that it could additionally be used for hauling drinking water. It could also be used for things like spraying the mud off gear before putting it back in the car, or hosing off dirty dishes when camping.
Lots of people already use solar bag showers for the same purpose, although Joel states that those can be easily punctured, need to be hung up, don’t have particularly high pressure, and can’t be heated while you’re in transit.
He has reportedly already sold 100 of his Road Showers, but has now turned to Kickstarter in order to raise funds for going into commercial-scale production. A pledge of US$210 will get you one, when and if the funding goal is met. If not, you can still buy one for $299.95 from his existing website.
The device can be seen in use in the pitch video below.
Recently, showers like the Nebia and the Hamwell’s e-Shower have launched to help us save water when showering. The WaterDrop foldable watering can, however, takes a much simpler approach. It is designed to collect the average 3.5 l (0.8 gal) of water we waste waiting for the shower to warm up.
Designed by Spanish startup Esferic, saving water is only part of the WaterDrop’s aim. It is also hoped that it will help to “promote a societal shift in water consumption habits” by increasing people’s awareness about the need to be frugal with water.
Nonetheless, Esferic says daily use of the Waterdrop will save users more than 1,000 l (220 gal) of water a year. It is made of recyclable thermoplastic polyurethane and takes the form of a tote bag with a reinforced handle so as to allow for the easy collection, storage and transportation of water.
To use the WaterDrop, users simply need to hold it under a shower head until the water runs warm. They can then continue with their shower, while the water collected can then be used for other domestic purposes, such as filling a mop bucket, watering plants or even flushing the toilet.
Esferic says it plans to develop a mobile app to accompany the WaterDrop so that users can measure the water savings they are making. A Kickstarter crowdfunding campaign for the WaterDrop was successfully completed today. If all goes to plan, shipping to backers is estimated to start in March.
The video below provides an introduction to the WaterDrop.
Users can create individual profiles on the smartphone app to log showers and track overall water usage
It can be pretty easy to lose sight of your water usage when taking a shower. Indeed standing under that powerful stream is a perfect way to churn through a lot of both water and energy. The team behind Hydrao is aiming to build awareness around these important resources, with an LED-equipped shower head that changes color when you’re overstaying your welcome.
Over the years we have seen a number of tech-inspired solutions to cutting water usage in the bathroom. Showers that purify and reuse the water that goes down the drain, designs that atomize water into tiny droplets rather than pushing out larger ones, and illuminated shower heads that go from green to red when it’s time to get out are just a few examples.
Hydrao follows the lead of this final approach, but does look to be particularly well executed. The shower head can designed to be screwed into a standard shower hose and is fitted with an LED light that’s powered by the water flowing through it, so there’s no batteries involved. It starts out as green when you first hop in, then morphs to blue once 10 L (2.64 gal) is used, orange once you hit 30 L (8 gal) and flashes red when you’ve used 50 L (13.2 gal).
It also connects with a smartphone app over Bluetooth, where users can create individual profiles to log showers and track overall water usage, customize the color configurations and set water savings targets.
After showcasing the device at CES earlier this month, Hydrao plans to start shipping the US$100 shower head this year with pre orders available via the source link. You can check out the promo video below.
New analysis of data collected by ESA’s Rosetta orbiter has revealed significant quantities of water ice on the comet 67P/Churyumov–Gerasimenko (67P). While the presence of water had previously been observed on 67P both in the comet’s coma, and as frost on the surface, this discovery represents the first time that a surface deposit of water ice has ever been definitively confirmed on the comet.
The discovery was made using data from Rosetta’s Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) collected between September and November 2014. The instrument focused on two bright deposits present on the comet’s Imhotep region.
Vast quantities of water vapor had previously been detected in the 67P’s coma, with scientists theorizing the source of the water to be located beneath the dust shrouded crust of the comet. Therefore, the newly confirmed surface deposit may be the result of some form of erosion process.
Image of 67P highlighting the positions of the two ice deposits
Pixel sampling of the bright deposits via the VIRTIS instr
ument revealed a yield of roughly 5 percent pure water ice. Rosetta scientists were also able to define two separate sizes of grains present in the samples – one tens of micrometers in diameter, and a second much larger population around 2 mm in diameter.
There are two theories as to how the larger grains may have come to form. The first involves a process known as sintering, by which many smaller particles are compacted together to form secondary ice crystals. The second possibility is that the grains could have formed as a result of sublimation.
Sublimation occurs when heat emanating from the Sun warms the comet, evaporating the water ice deposits buried beneath its crust. It is possible that, in very cold conditions such as those prevailing within 67P, the sublimation process could be aided by extra energy created as amorphous ice deposits transform into crystalline ice on a molecular level.
ESA graphic detailing the presence of water ice present in the Imhotep region of 67P
However, the majority of the water vapor created via the process fails to escape the surface. ESA has carried out laboratory tests simulating the sublimation process believed to be taking place on 67P. The results indicated that only a relatively small percentage would escape the surface, roughly 80 percent of the vapor could remain near the surface, potentially forming an ice layer several meters thick.
Looking forward, Rosetta’s science team intend to analyze data collected mid-way through 2015 as the comet made its approach to perihelion in order to determine the extent to which the exposed deposits of water ice were affected by close proximity to the Sun.
A paper on the study has been published online in the journal Nature.