Bio-inspired bleeding control: Synthesized platelet-like nanoparticles created

Artist's rendering of synthetic platelets. Credit: Peter Allen illustration

Stanching the free flow of blood from an injury remains a holy grail of clinical medicine. Controlling blood flow is a primary concern and first line of defense for patients and medical staff in many situations, from traumatic injury to illness to surgery. If control is not established within the first few minutes of a hemorrhage, further treatment and healing are impossible.

At UC Santa Barbara, researchers in the Department of Chemical Engineering and at Center for Bioengineering (CBE) have turned to the human body's own mechanisms for inspiration in dealing with the necessary and complicated process of coagulation. By creating nanoparticles that mimic the shape, flexibility and surface biology of the body's own platelets, they are able to accelerate natural healing processes while opening the door to therapies and treatments that can be customized to specific patient needs.

"This is a significant milestone in the development of synthetic platelets, as well as in targeted drug delivery," said Samir Mitragotri, CBE director, who specializes in targeted therapy technologies. Results of the researchers' findings appear in the current issue of the journal ACS Nano.

The process of coagulation is familiar to anyone who has suffered even the most minor of injuries, such as a scrape or paper cut. Blood rushes to the site of the injury, and within minutes the flow stops as a plug forms at the site. The tissue beneath and around the plug works to knit itself back together and eventually the plug disappears.

But what we don't see is the coagulation cascade, the series of signals and other factors that promote the clotting of blood and enable the transition between a free-flowing fluid at the site and a viscous substance that brings healing factors to the injury. Coagulation is actually a choreography of various substances, among the most important of which are platelets, the blood component that accumulates at the site of the wound to form the initial plug.

"While these platelets flow in our blood, they're relatively inert," said graduate student researcher Aaron Anselmo, lead author of the paper. As soon as an injury occurs, however, the platelets, because of the physics of their shape and their response to chemical stimuli, move from the main flow to the side of the blood vessel wall and congregate, binding to the site of the injury and to each other. As they do so, the platelets release chemicals that "call" other platelets to the site, eventually plugging the wound.

But what happens when the injury is too severe, or the patient is on anti-coagulation medication, or is otherwise impaired in his or her ability to form a clot, even for a modest or minor injury?

That's where platelet-like nanoparticles (PLNs) come in. These tiny, platelet-shaped 

particles that behave just like their human counterparts can be added to the blood flow to supply or augment the patient's own natural platelet supply, stemming the flow of blood and initiating the healing process, while allowing physicians and other caregivers to begin or continue the necessary treatment. Emergency situations can be brought under control faster, injuries can heal more quickly and patients can recover with fewer complications.

"We were actually able to render a 65 percent decrease in bleeding time compared to no treatment," said Anselmo.

According to Mitragotri, the key lies in the PLNs' mimicry of the real thing. By imitating the shape and flexibility of natural platelets, PLNs can also flow to the injury site and congregate there. With surfaces functionalized with the same biochemical motifs found in their human counterparts, these PLNs also can summon other platelets to the site and bind to them, increasing the chances of forming that essential plug. In addition, and very importantly, these platelets are engineered to dissolve into the blood after their usefulness has run out. This minimizes complications that can arise from emergency hemostatic procedures.

"The thing about hemostatic agents is that you have to intervene to the right extent," said Mitragotri. "If you do too much, you cause problems. If you do too little, you cause problems."

These synthetic platelets also let the researchers improve on nature. According to Anselmo's investigations, for the same surface properties and shape, nanoscale particles can perform even better than micron-size platelets. Additionally, this technology allows for customization of the particles with other therapeutic substances -- medications, therapies and such -- that patients with specific conditions might need.

"This technology could address a plethora of clinical challenges," said Dr. Scott Hammond, director of UCSB's Translational Medicine Research Laboratories. "One of the biggest challenges in clinical medicine right now -- which also costs a lot of money -- is that we're living longer and people are more likely to end up on blood thinners. When an elderly patient presents at a clinic, it's a huge challenge because you have no idea what their history is and you might need an intervention."

With optimizable PLNs, physicians would be able to strike a finer balance between anticoagulant therapy and wound healing in older patients, by using nanoparticles that can target where clots are forming without triggering unwanted bleeding. In other applications, bloodborne pathogens and other infectious agents could be minimized with antibiotic-carrying nanoparticles. Particles could be made to fulfill certain requirements to travel to certain parts of the body -- across the blood-brain barrier, for instance -- for better diagnostics and truly targeted therapies.

Additionally, according to the researchers, these synthetic platelets cost relatively less, and have a longer shelf life than do human platelets -- a benefit in times of widespread emergency or disaster, when the need for these blood components is at its highest and the ability to store them onsite is essential.

Further research into PLNs will involve investigations to see how well the technology and synthesis can scale up, as well as assessments into the more practical matters involved in translating the technology from the lab to the clinic, such as manufacturing, storage, sterility and stability as well as pre-clinical and clinical testing.

Source: University of California - Santa Barbara

Read More

Ultrasounds dance the 'moonwalk' in new metamaterial

Silicone beads embedded in a water-based gel (photograph is ~2 cm across). Credit: © CRPP

Metamaterials have extraordinary properties when it comes to diverting and controlling waves, especially sound and light: for instance, they can make an object invisible, or increase the resolving power of a lens. Now, researchers at the Centre de Recherche Paul Pascal (CNRS) and the Institut de Mécanique et d'Ingénierie de Bordeaux (CNRS/Université de Bordeaux/Bordeaux INP/Arts et Métiers ParisTech) have developed the first three-dimensional metamaterials by combining physico-chemical formulation and microfluidics technology. This is a new generation of soft metamaterials that are easier to shape. In their experiment, the researchers got ultrasonic oscillations to move backwards while the energy carried by the wave moved forwards. Their work opens up new prospects, especially for high-resolution imaging (ultrasonography). It is published on 15 December 2014 in the journal Nature Materials.

Since the 2000s, the international scientific community has seen interest in metamaterials and their extraordinary properties grow exponentially. A metamaterial is a medium in which the phase velocity of light or sound waves can be negative (the material is said to have a negative refractive index).. In such a medium, the phase of the wave (the successive oscillations) and the energy carried by this same wave move in opposite directions. This property is not found in any natural homogeneous medium.

To obtain a metamaterial, it is necessary to make a heterogeneous medium that contains a large number of inclusions (known as microresonators). The usual way is to use micromechanical methods (etching, deposition, etc) to machine solid supports that will have the properties of metamaterials in one or two dimensions. However, this method cannot be used to work with soft matter at the micrometer scales required for ultrasounds, and the materials obtained remain limited to one or two dimensions.

In this study, the researchers developed a new type of metamaterial, in the fluid phase, formed of porous silicone microbeads embedded in a water-based gel. This metafluid is the first three-dimensional metamaterial to work at ultrasonic frequencies. In addition, due to its fluid nature, it can be made using physico-chemical processes and microfluidics technologies, which are much easier to implement than micromechanical methods.

One of the properties of porous media is that sound travels through them at very low speed (a few tens of meters per second) compared to water (1500 meters per second). Due to this sharp contrast, the whole suspension has the properties of a metamaterial provided the bead concentration is sufficient: when the researchers studied the propagation of ultrasonic waves through this medium, they directly measured a negative refractive index. Within such a metafluid, the energy carried by the wave travels from the emitter to the receiver, as expected, whereas the oscillations appear to move backwards in the opposite direction, rather like a dancer doing the 'moonwalk'.

These results open the way to numerous applications ranging from high-resolution ultrasound imaging to sound insulation and stealth in underwater acoustics. In addition, the soft-matter physico-chemical techniques used to make this metamaterial makes it possible to produce fluid or flexible materials with adaptable shapes, potentially at the industrial scale.

Source: CNRS (Délégation Paris Michel-Ange)

Read More

Meteorology meets metrology: Climate research high up in the clouds

View along HALO's wing (with the aerosol instruments) above the Amazon rainforest.
Credit: Buchholz/PTB

Barely has the research aircraft HALO entered the kilometre-high clouds towering above the Brazilian rainforest than the researchers find themselves in a complete haze, but they can rely on the measuring instruments that are working at full capacity. HAI -- a new, highly accurate hygrometer of the Physikalisch-Technische Bundesanstalt (PTB) -- is aboard. The shooting star among hygrometers has been developed only recently by metrologists (metrology = the science of measurement) especially for use on board aircraft and in the clouds, but it has already been used in four research campaigns and has already clocked up more than 300 hours of active use. It is the only device worldwide that can determine precisely and simultaneously how much of the water present in the atmosphere is in the form of vapour, condensation, droplets or ice.

These data help us understand natural and anthropogenic cloud formation processes and how they influence the climate. HAI is robust enough for field use at strongly varying temperatures and pressures and it is also coupled to the international humidity scale. Furthermore, it requires no time-consuming calibration. Its unique features combine applied climate research with metrology's most demanding requirements.

HAI is an acronym that stands for Hygrometer for Atmospheric Investigations. Its latest assignment (within the scope of the ACRIDICON-CHUVA mission) took it on a large-scale expedition in which approx. 60 scientists from Germany, Israel and Brazil were involved. On board HALO, one of the most modern measurement aircraft for atmospheric research -- operated by the Deutsches Luft- und Raumfahrtzentrum (DLR -- the national aeronautics and space research centre of the Federal Republic of Germany) -- HAI again and again flew into the clouds rising above the Amazon rainforest to collect samples. The researchers wanted to find out, among other things, which influence air pollution above cities or slash-and-burn areas have on the formation of clouds.

Water is the most important greenhouse gas and plays various roles in climate development. Clouds shade and cool down the surface of Earth; at the same time, they act as an insulation layer, keeping the terrestrial thermal radiation from escaping into space. The total global water cycle is based on the humidity present in the air heating up and cooling down again. 

Furthermore, humidity values serve as a correction coefficient in many other atmospheric measurements. Water is the most influential greenhouse gas, this is a fact. But putting a figure on its influence in order to set up models on climate development is a very difficult task. Depending on how high the clouds are as well as on their exact composition (they can consist of vapour, droplets and ice in varying amounts), they can have very diverse effects. Also, the measurement of the different phases of water is a complex task as its state of matter may already be influenced decisively the moment the sample is taken: for example, water vapour can already condensate to droplets on its way to the measuring instrument due to cooling while the sample is being collected.

Scientists from PTB have solved this problem by means of the HAI multi-phase water sensor. HAI simultaneously determines how much water vapour and how much condensed water is present in the air; a robust, open and aerodynamic measuring cell located outside the aircraft body directly measures the gaseous water vapour content of the air flowing through it. Another two-channel measuring unit is located inside the aircraft, at the end of a heated sample collection tube where two sensors working independently of each other measure the total water content of the sample. The difference between the total water content measured and the result of the measurement carried out in the gaseous phase allow the content of condensed water to be determined simultaneously.

HAI is based on a special variant of TDLAS (Tunable Diode Laser Absorption Spectroscopy) which is self-calibrating. The previously required time-consuming calibration, which was excessively difficult to carry out accurately and frequently enough in the field, has, thus, become obsolete. In addition, HAI, in combination with HALO, is the first airborne fast hygrometer in use that is directly traced back to the metrological humidity scale. Contrary to most other hygrometers, it provides results with low and clearly defined measurement uncertainty, in accordance with strict metrological requirements.

Source: Physikalisch-Technische Bundesanstalt (PTB)

Read More

Better dam planning strategies

This is a map showing combined effect of current and future dams. Credit: McGill University

When dams are built they have an impact not only on the flow of water in the river, but also on the people who live downstream and on the surrounding ecosystems. By placing data from close to 6,500 existing large dams on a highly precise map of the world's rivers, an international team led by McGill University researchers has created a new method to estimate the global impacts of dams on river flow and fragmentation.

Among their findings, published online today in Environmental Research Letters: 48% of the world's river volume is moderately or severely affected by dams today -- and that figure would nearly double if all dams planned or under construction are completed in the future.

"Over the past 60 years, a myriad of dams have been built either to provide hydroelectric power, or for irrigation purposes, or as flood protection," says Bernhard Lehner, a professor in McGill University's Department of Geography and the research director of the project. "The construction of large dams then slowed down for the last 20 years as we became more aware of their negative effects on people and ecosystems. But now, with fears about how climate change may affect water flows in the future, the goal of creating reservoirs is once more appealing, and dam construction is on the rise."

The new research was made possible by the team's development of a global river map with unprecedented resolution and detail, showing all waterways of the world from small creeks to the largest of rivers, accounting for a cumulative river length of 48.3 million km -- and by a new map of future dam locations assembled by colleagues at the Leibniz-Institute of Freshwater Ecology and Inland Fisheries in Berlin.

The key components of the team's dam assessment method are two indices that describe river fragmentation and river regulation.

The river fragmentation index (RFI) is a measure of the way that a river's natural flow path (also known as its connectivity) has been disrupted by the creation of dams or by barriers that allow for the transfer of water between basins or towards irrigation areas, for example.

The river regulation index (RRI) is a measure of the proportion of the river water that can be stored in reservoirs, and thus affects the natural fluctuation and properties of river flow downstream.

By combining these two indices, the researchers have arrived at a way of assessing the impact of any existing or planned dam. So, for example, the Danube is severely impacted by fragmentation effects but is relatively weakly affected in terms of flow regulation due to many dams with relatively small reservoirs. The Murray-Darling basin in southern Australia, by contrast, is only weakly affected by fragmentation, but is heavily impacted by flow regulation, due to fewer but larger reservoirs.

"Not all dams are equal," says Günther Grill, a postdoctoral fellow in McGill University's Department of Geography and the lead author on the paper. "Our research assumes that it is not only the size of a dam but also where it is placed along the river that makes a difference. So depending on whether a dam is high up in the mountain headwaters or further down close to the delta, if it is on the main stem of the river or on a small tributary, all of these factors will have varying effects on the rivers and their surrounding ecosystems."

Researchers at the University of Minnesota's Institute on the Environment and the University of Wisconsin's Center for Limnology also contributed to the study.

Some dam and river facts:

There are 6,374 large dams already in existence and 3,377 planned or proposed large dams to be built by 2030.

Currently 48% of the world's river volume is moderately or severely affected by either flow regulation or fragmentation or both.

Assuming that all the dams that are planned or under construction are completed, this number would almost double to 93%, largely due to multiple dams being planned for major tributaries in the Amazon Basin.

Other large rivers that are currently rather free-flowing but on which large dams are planned are the Mekong River in Southeast Asia and the Amur River in Russia.

Source: McGill University

Read More

Robots take over inspection of ballast tanks on ships

Doctoral degree candidate Dian Borgerink of the Robotics and Mechatronics department at the University of Twente developed the build-on robotic arm for RoboShip, working together with the department's chairman, Stefano Stramigioli, and master's student Jop Huttenhuis.
Credit: Image courtesy of University of Twente

A new robot for inspecting ballast water tanks on board ships is being developed by a Dutch-German partnership including the University of Twente. The robot is able to move independently along rails built into the tanks. At the moment, people still carry out such inspections, with ships being brought into dry dock for the purpose. The costs can be as high as € 700,000 per inspection. The RoboShip project offers great advantages, not only in terms of cost but also in terms of safety.

RoboShip is an independent, intelligent robotic platform on rails for use within the shipping industry. The parties involved in the RoboShip project brought together a number of innovations in it. Imotect, for example, developed a smart, cost-efficient rail, while DFKI was responsible for an autonomous vehicle to run along the rails. Incas³ developed the sensors, Xsens developed the tank navigation system, and the University of Twente was responsible for ensuring that a thorough inspection of the ballast water tanks is carried out using the equipment. The Meyer Werft shipyard in Germany has now also joined the project and will be integrating RoboShip into the ships it builds.

Operators are able to determine the exact position of the robot within the ballast water tanks thanks to a magnetic field. Other developments include a simple way of building synthetic rails into ships, an improvement to the supply of energy through the rails and advanced communication and navigation systems.

Current inspections: dangerous and expensive

Ballast water tanks are either filled with seawater or are left empty. Seawater is extremely aggressive and attacks steel. This is why regular inspection from within is required. Current practice is for a group of six inspectors to carry out such inspections. In doing so, they run the risk of injury through falls or of breathing in noxious gases. The autonomous RoboShip inspection robot makes such risks a thing of the past. Using the robot also greatly improves the efficiency of inspections.

Inspectors evaluate the data transmitted on a screen outside of the ballast water tank, considerably reducing the overall time required for inspecting a ship. The time that liners need to spend in dock can also be considerably reduced as tank inspections can take place while the ship is still in operation. Any repairs required can then be scheduled in before the ship goes to dry dock. Having a ship in dock is, after all, an expensive business, with costs running into the hundreds of thousands of euros. In the future, when the energy supply through the rails has been further improved, the robot will be able to work on the ballast water tank's surfaces using a laser. It will then be able to remove paint residues, for example, and it will also become possible to clean and coat the tanks.

Robotic arm from Twente

Doctoral degree candidate Dian Borgerink of the Robotics and Mechatronics department at the University of Twente developed the build-on robotic arm for RoboShip, working together with the department's chairman, Stefano Stramigioli, and master's student Jop Huttenhuis. Borgerink also works for the INCAS³ research institute, which developed the sensor system on the arm.

"I have had the opportunity of seeing the inside of a freighter's ballast water tank," says Borgerink. "After a voyage, it is slippery with seaweed and is full of noxious gases. Tanks like these are almost inaccessible due to ribs, pipes and cables. Realising that people actually need to go into them to carry out inspection work was what motivated me to develop the robotic arm." While designing the robotic arm, Borgerink and his colleagues were presented with many challenges. The arm needed to be collapsible, lightweight and accurate. The research carried out has already been presented at IROS 2014 in Chicago, a leading conference for the robotics and automation sector.

The Roboship research is funded by the German-Dutch INTERREG IVA subsidy programme.

Source: University of Twente

Read More

Microplastics in the ocean: Biologists study effects on marine animals

A marine isopod of the genus Idotea with food pellets.
Credit: Photo Alfred Wegener Institute / Julia Hämer

Ingestion of microplastic particles does not mechanically affect marine isopods. This was the result of a study by biologists at the North Sea Office of the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) that was published recently in the journal Environmental Science and Technology. The study marks the launch of a series of investigations aimed at forming a risk matrix on the sensitivity of different marine species to microplastic pollution.

Uptake of large plastic items by birds and fish may cause blockage of the gastrointestinal tract and severe starvation of the animals. "We were wondering whether small plastic particles have a comparable effect on smaller animals," says Dr. Lars Gutow from AWI's North Sea Office. "Only very limited research has been done on the effects of microplastics on living beings. Accordingly, there is great uncertainty about the implications for marine animals," the biologist explains the motivation for the study.

Lars Gutow and his colleagues selected the isopod Idotea emarginata as their model organism for an initial case study. In feeding experiments the researchers offered the isopods artificial algal food supplemented with plastic particles. The food contained three different kinds of microplastics in varying concentrations. They used industrially produced polystyrene particles with a diameter of ten micrometers as well as self-made fragments and fibres made of polyethylene and polyacryl, respectively.

The researchers studied the fate of the different materials under a light microscope, with the help of a fluorescence microscope, and with an electron microscope. They were able to trace the path of the microplastic particles through the isopods and determine the concentrations of the particles in different sections of the digestive system. The study showed that the concentration of microplastics in the faecal material of the isopods was as high as in the food. The scientists found small amounts of microplastics both in the stomach and in the gut of the animals. However, they did not detect any microparticles in the digestive glands. "The isopods ingested and excreted the artificial food with the microplastic particles without absorbing or accumulating the particles," Gutow summarises the results. Thus, plastic particles in the specific size range studied do not represent a direct mechanical risk for isopods and probably not for other crustaceans either. "In the case of Idotea emarginata, the microplastic particles did not enter the digestive gland, which is the principle organ in crustaceans where digestion and resorption of nutrients takes place," states the biologist from AWI's North Sea Office.

In a long-term experiment the scientists could also show that isopods did not display any long-term effects even after feeding on microplastic enriched food for six to seven weeks. 

Fitness parameters such as survival rate and growth did not differ between animals that were fed with and without microplastics, respectively. In an earlier study, however, AWI biologist Prof. Dr. Angela Köhler demonstrated that mussels show inflammatory reactions if they take up and absorb high concentrations of microplastic in an experiment. This clearly shows that different animal species react differently to microplastics. "In contrast to filter feeding mussels, isopods of the genus Idotea probably take up more frequently indigestible particles with their food in their natural habitat and may, thus, have adapted accordingly," elucidates Gutow.

But the biologists are not only interested in the feeding type: "We want to study systematically how the life style, habitat, physiology and anatomy of different marine organisms influence the uptake and utilisation of microplastic particles in order to come up with a risk matrix for diverse types of organisms," says Lars Gutow. "Therefore, it will be necessary to also study the possible chemical (toxic) and biochemical effects in addition to the physical effects that we looked at," he outlines future tasks.

Source: Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research

Read More

Yellowstone's thermal springs: Their colors unveiled

This is a photograph of Morning Glory Pool from Aug. 23, 2012.
Credit: Joseph Shaw, Montana State University

Researchers at Montana State University and Brandenburg University of Applied Sciences in Germany have created a simple mathematical model based on optical measurements that explains the stunning colors of Yellowstone National Park's hot springs and can visually recreate how they appeared years ago, before decades of tourists contaminated the pools with make-a-wish coins and other detritus.

The model, and stunning pictures of the springs, appear today in the journal Applied Optics, which is published by The Optical Society (OSA).

If Yellowstone National Park is a geothermal wonderland, Grand Prismatic Spring and its neighbors are the ebullient envoys, steaming in front of the camera and gracing the Internet with their ethereal beauty. While the basic physical phenomena that render these colorful delights have long been scientifically understood -- they arise because of a complicated interplay of underwater vents and lawns of bacteria -- no mathematical model existed that showed empirically how the physical and chemical variables of a pool relate to their optical factors and coalesce in the unique, stunning fashion that they do.

"What we were able to show is that you really don't have to get terribly complex -- you can explain some very beautiful things with relatively simple models," said Joseph Shaw, a professor at Montana State University and director of the university's Optical Technology Center. Shaw, along with his Ph.D. student Paul Nugent and German colleague Michael Vollmer, co-authored the new paper.

Using a relatively simple one-dimensional model for light propagation, the group was able to reproduce the brilliant colors and optical characteristics of Yellowstone National Park's hot springs by accounting for each pool's spectral reflection due to microbial mats, their optical absorption and scattering of water and the incident solar and diffuse skylight conditions present when measurements were taken.

"When we started the study, it was clear we were just doing it for fun," Vollmer said. But they quickly discovered there was very little in the scientific literature on the subject. That's when things got interesting.

Montana State University, in Bozeman, Mont., is a short drive away from Yellowstone National Park. In the summer of 2012, Vollmer, on sabbatical from the Brandenburg University of Applied Sciences, travelled with Shaw and Nugent to the park. Using handheld spectrometers, digital SLR cameras for visible images and long wave infrared thermal imaging cameras for non-contact measurement of the water temperatures, the group took measurements at a number of pools in Yellowstone, including Morning Glory Pool, Sapphire Pool and Grand Prismatic Spring. Using these data, along with previously available information about the physical dimensions of the pools, they were able to create a simple model whose renderings of the pools were strikingly similar to actual photographs.

In the case of Morning Glory Pool, they were even able to simulate what the pool once looked like between the 1880s and 1940s, when its temperatures were significantly higher. 

During this time, its waters appeared a uniform deep blue. An accumulation of coins, trash and rocks over the intervening decades has partially obscured the underwater vent, lowering the pool's overall temperature and shifting its appearance to a terrace of orange-yellow-green. This change from blue was demonstrated to result from the change in composition of the microbial mats, as a result of the lower water temperature.

A general relationship between shallow water temperature (hence microbial mat composition) and observed colors was confirmed in this study. However, color patterns observed in deeper segments of the pool are caused more by absorption and scattering of light in the water. These characteristics -- mats having greater effect on color in shallow water, and absorption and scattering winning out in the deeper areas -- are consistent across all the measured pools.

"Our paper describes a very simple, one-dimensional model, that gives the first clue if you really want to do more," Vollmer said.

"We didn't start this project as experts on thermal pools," Shaw said. "We started this project as experts on optical phenomena and imaging, and so we had a lot to learn."

"There are people at my university who are world experts in the biological side of what's going on in the pools," Shaw said. "They're looking for ways to monitor changes in the biology -- when the biology changes, that causes color changes -- so we're actually looking at possibilities of collaborating in the future."

Future work for Nugent, Vollmer and Shaw includes delving further into infrared imaging at Yellowstone National Park.

Source:  American Institute of Physics (AIP)

Read More

Ancient, hydrogen-rich waters deep underground around the world: Waters could support isolated life

Energy-rich waters discharge kilometers below the surface in a South African mine.
Credit: G. Borgonie, 2014

A team of scientists, led by the University of Toronto's Barbara Sherwood Lollar, has mapped the location of hydrogen-rich waters found trapped kilometres beneath Earth's surface in rock fractures in Canada, South Africa and Scandinavia.

Common in Precambrian Shield rocks -- the oldest rocks on Earth -- the ancient waters have a chemistry similar to that found near deep sea vents, suggesting these waters can support microbes living in isolation from the surface.

The study, to be published in Nature on December 18, includes data from 19 different mine sites that were explored by Sherwood Lollar, a geoscientist at U of T's Department of Earth Sciences, U of T senior research associate Georges Lacrampe-Couloume, and colleagues at Oxford and Princeton universities.

The scientists also explain how two chemical reactions combine to produce substantial quantities of hydrogen, doubling estimates of global production from these processes which had previously been based only on hydrogen coming out of the ocean floor.

"This represents a quantum change in our understanding of the total volume of Earth's crust that may be habitable," said Sherwood Lollar.

"Until now, none of the estimates of global hydrogen production sustaining deep microbial populations had included a contribution from the ancient continents. Since Precambrian rocks make up more than 70 per cent of the surface of Earth's crust, Sherwood Lollar likens these terrains to a "sleeping giant," a huge area that has now been discovered to be a source of possible energy for life," she said.

One process, known as radiolytic decomposition of water, involves water undergoing a breakdown into hydrogen when exposed to radiation. The other is a chemical reaction called serpentization, a mineral alteration reaction that is common in such ancient rocks.
This study has important implications for the search for deep microbial life. Quantifying the global hydrogen budget is key to understanding the amount of Earth's biomass that is in the subsurface, as many deep ecosystems contain chemolithotrophic -- so-called "rock-eating" -- organisms that consume hydrogen. In the deep gold mines of South Africa, and under the sea, at hydrothermal vents where breaks in the fissure of Earth's surface that release geothermally heated waters -- hydrogen-rich fluids host complex microbial communities that are nurtured by the chemicals dissolved in the fluids. This study identifies a global network of sites with hydrogen-rich waters that will be targeted for exploration for deep life over the coming years.

Further, because Mars -- like the Precambrian crust -- consists of billions-of-year-old rocks with hydrogen-producing potential, this finding has ramifications for astrobiology. "If the ancient rocks of Earth are producing this much hydrogen, it may be that similar processes are taking place on Mars," said Sherwood Lollar.

Other key members of the research team are Chris Ballentine of Oxford University, Tulis Onstott at Princeton University and Georges Lacrampe-Couloume of the University of Toronto. The research was funded by the Canada Research Chairs program, the Natural Sciences & Engineering Research Council, the Sloan Foundation Deep Carbon Observatory, the Canadian Space Agency and the National Science Foundation.

Source: University of Toronto

Read More

Put a plastic bag in your tank: Converting polyethylene waste into liquid fuel

Researchers in India have developed a relatively low-temperature process to convert certain kinds of plastic waste into liquid fuel as a way to re-use discarded plastic bags and other products.

Researchers in India have developed a relatively low-temperature process to convert certain kinds of plastic waste into liquid fuel as a way to re-use discarded plastic bags and other products. They report full details next month in the International Journal of Environment and Waste Management.

Many pundits describe the present time as the "plastic age" for good reason and as such we generate a lot plastic waste. Among that waste is the common polymer, low-density polyethylene (LDPE), which is used to make many types of container, medical and laboratory equipment, computer components and, of course, plastic bags. Recycling initiatives are in place in many parts of the world, but much of the polyethylene waste ends up in landfill, dispersed in the environment or in the sea.

Chemist Achyut Kumar Panda of Centurion University of Technology and Management Odisha, India is working with chemical engineer Raghubansh Kumar Singh of the National Institute of Technology, Orissa, India, to develop a commercially viable technology for efficiently rendering LDPE into a liquid fuel. Given that most plastics are made from petrochemicals, this solution to plastic recycling brings the life-cycle full circle allowing a second use as an oil substitute. The process could, if implemented on a large enough scale, reduce pressures on landfill as well as ameliorating the effects of dwindling oil supplies in a world with increasing demands on petrochemicals for fuel.

In their approach, the team heats the plastic waste to between 400 and 500 Celsius over a kaolin catalyst. This causes the plastic's long chain polymer chains to break apart in a process known as thermo-catalytic degradation. This releases large quantities of much smaller, carbon-rich molecules. The team used the analytical technique of gas chromatography coupled mass spectrometry to characterize these product molecules and found the components of their liquid fuel to be mainly paraffins and olefins 10 to 16 carbon atoms long. This, they explain, makes the liquid fuel very similar chemically to conventional petrochemical fuels.

In terms of the catalyst, Kaolin is a clay mineral -- containing aluminum and silicon. It acts as a catalyst by providing a large reactive surface on which the polymer molecules can sit and so be exposed to high temperature inside the batch reactor, which breaks them apart. The team optimized the reaction at 450 Celsius a temperature with the lowest amount of kaolin at which more than 70% of the liquid fuel is produced. In other words, for every kilogram of waste plastic they could produce 700 grams of liquid fuel. The byproducts were combustible gases and wax. They could boost the yield to almost 80% and minimize reaction times, but this required a lot more catalyst 1 kg of kaolin for every 2 kg of plastic.

Source: Inderscience Publishers

Read More

Recovering metals and minerals from waste

When water and wastewater systems are developed in a comprehensive manner, it is possible to recover valuable metals and other materials and secure availability of clean water.

Scarcity of clean water is one of the most serious global challenges. In its spearhead programme, VTT Technical Research Centre of Finland developed energy-efficient methods for reuse of water in industrial processes and means for recovering valuable minerals and materials from waste for recycling. Rapid tools were also developed for identification of environmental pollutants.

When water and wastewater systems are developed in a comprehensive manner, it is possible to recover valuable metals and other materials and secure availability of clean water. Cleaning and treatment processes can also be linked to energy production, and the processes and urban structures designed in such a manner that wastewater treatment does not consume energy or cause extra costs.

"Wastewater treatment and waste treatment have mainly been implemented by legal necessity. Now we should modify our way of thinking so that we would be able to regard waste disposal sites and purification plants as sources or raw materials and energy. In the near future, technology has been refined far enough to allow such waste treatment plants to operate on their own," says Mona Arnold, Principal Researcher at VTT.

Recycling valuable minerals and materials

Demand has arisen for technologies capable of recovering even tiny amounts of minerals from waste flows. Recovering them from municipal or mining wastewaters requires better recovery methods than those available today. VTT has developed extraction methods for metals and minerals from waste materials. Biological extraction methods by which metals are recovered from mining, metal and recycling industry waste by utilising microbes and chemical reactions are under testing stages and they are forcasted for market uptake within the next few years.

Other valuable elements can also be found from waste flows. For example, the food industry by-product flows contain biochemicals and proteins that can be utilised better than is currently possible, if only they could be effectively recovered from waste. One possibility is to use enzymes. VTT researchers developed an enzyme-assisted method by which feed products can be produced from side streams deriving from turnip rape processing in food industry.

Reducing energy consumption in water treatment

Treatment of water in purification plants and industrial facilities consumes vast amounts of energy. Usually water recycling and seawater desalination are based on the use of filtration membranes that consume energy. VTT developed intelligent membrane materials, reducing the need of purification, for filtration purposes.

Membrane solutions using only small amounts of energy were developed for water treatment purposes. VTT has collaborated with a university in Singapore to develop a method based on forward osmosis technology, by which metals and biocomponents can be recovered and concentrated from industrial process waters.

The pumping and distribution of water to consumers and industry also consumes major amounts of energy. The need for pumping can be minimised if the process water can be recirculated within the plant, and the distribution network is made more effective by enhanced monitoring and location of leaks.

Sensors for identifying environmental hazards

The VTT spearhead programme also developed sensor technology for easy and rapid detection of pollutants. VTT indicators facilitate rapid identification of, for example, small but hazardous cyanobacterial toxin levels and phenolic, hormone-like compounds. There is need for such indicators in developing countries, suffering from lack of trained personnel and laboratories. The technology will be ready for production use within the next few years.

Source: Technical Research Centre of Finland (VTT).

Read More

Maize and bacteria: A one-two punch knocks copper out of stamp sand

Maize plants grown in stamp sand inoculated with bacteria, left, were considerably more robust than those grown in stamp sand alone, right. This research could lead to new remediation techniques for soils contaminated by copper and other heavy metals.
Credit: Image courtesy of Michigan Technological University

Scientists have known for years that together, bacteria and plants can remediate contaminated sites. Ramakrishna Wusirika, of Michigan Technological University, has determined that how you add bacteria to the mix can make a big difference.

He has also shed light on the biochemical pathways that allow plants and bacteria to clean up some of the worst soils on the planet while increasing their fertility.

Wusirika, an associate professor of biological sciences, first collected stamp sands near the village of Gay, in Michigan's Upper Peninsula. For decades, copper mining companies crushed copper ore and dumped the remnants -- an estimated 500 million tons of stamp sand -- throughout the region. Almost nothing grows on these humanmade deserts, which are laced with high concentrations of copper, arsenic and other plant-unfriendly chemicals.

Then, Wusirika and his team planted maize in the stamp sand, incorporating bacteria in four different ways:
1. mixing it in the stamp sand before planting seed;
2. coating seed with bacteria and planting it;
3. germinating seeds and planting them in soil to which bacteria were added; and
4. the conventional method, immersing the roots of maize seedlings in bacteria and planting them in stamp sand.

After 45 days, the team uprooted the plants and measured their dry weight. All maize grown with bacteria was significantly more vigorous -- from two to five times larger -- than the maize grown in stamp sand alone. The biggest were those planted as seedlings or as germinated seeds.

However, when the researchers analyzed the dried maize, they made a surprising discovery: the seed-planted maize took up far more copper as a percentage of dry weight. In other words, the smaller plants pulled more copper, ounce per ounce, out of the stamp sands than the bigger ones.

That has implications for land managers trying to remediate contaminated sites, or even for farmers working with marginal soils, Wusirika said. The usual technique -- applying bacteria to seedlings' roots before transplanting -- works fine in the lab but would be impractical for large-scale projects. This could open the door to simple, practical remediation of copper-contaminated soils.

But the mere fact that all the plants grown with bacteria did so well also piqued his curiosity. "When we saw this, we wondered what the bacteria were doing to the soil," Wusirika said. "Based on our research, it looks like they are improving enzyme activity and increasing soil fertility," in part by freeing up phosphorus that had been locked in the rock.

The bacteria are also changing copper into a form that the plants can take up. "With bacteria, the exchangeable copper is increased three times," he said. "There's still a lot of copper that's not available, but it is moving in the right direction."

By analyzing metabolic compounds, the team was able to show that the bacteria enhance photosynthesis and help the plants make growth hormones. Bacteria also appear to affect the amount phenolics produced by the maize. Phenolics are antioxidants similar to those in grapes and red wine.
Compared to plants grown in normal soil without bacteria, plants grown in stamp sand alone showed a five-fold increase in phenolics. However, phenolics in plants grown in stamp sand with bacteria showed a lesser increase.

"Growing in stamp sand is very stressful for plants, and they respond by increasing their antioxidant production," Wusirika said. "Adding the metal-resistant bacteria enables the plants to cope with stress better, resulting in reduced levels of phenolics."

"There's still a lot to understand here," he added. "We'd like to do a study on stamp sands in the field, and we'd also like to work with plants besides maize. We think this work has applications in organic agriculture as well as remediation."

Source:  Michigan Technological University

Read More

Hydraulic fracturing linked to earthquakes in Ohio

Seismograph (stock image). Hydraulic fracturing triggered a series of small earthquakes in 2013 on a previously unmapped fault in Harrison County, Ohio, according to a study. Credit: © hakandogu / Fotolia

Hydraulic fracturing triggered a series of small earthquakes in 2013 on a previously unmapped fault in Harrison County, Ohio, according to a study published in the journal Seismological Research Letters (SRL).

Nearly 400 small earthquakes occurred between Oct. 1 and Dec. 13, 2013, including 10 "positive" magnitude earthquake, none of which were reported felt by the public. The 10 positive magnitude earthquakes, which ranged from magnitude 1.7 to 2.2, occurred between Oct. 2 and 19, coinciding with hydraulic fracturing operations at nearby wells.

This series of earthquakes is the first known instance of seismicity in the area.
Hydraulic fracturing, or fracking, is a method for extracting gas and oil from shale rock by injecting a high-pressure water mixture directed at the rock to release the gas inside. The process of hydraulic fracturing involves injecting water, sand and chemicals into the rock under high pressure to create cracks. The process of cracking rocks results in micro-earthquakes. Hydraulic fracturing usually creates only small earthquakes, ones that have magnitude in the range of negative 3 (−3) to negative 1 (-1).

"Hydraulic fracturing has the potential to trigger earthquakes, and in this case, small ones that could not be felt, however the earthquakes were three orders of magnitude larger than normally expected," said Paul Friberg, a seismologist with Instrumental Software Technologies, Inc. (ISTI) and a co-author of the study.

The earthquakes revealed an east-west trending fault that lies in the basement formation at approximately two miles deep and directly below the three horizontal gas wells. The EarthScope Transportable Array Network Facility identified the first earthquakes on Oct. 2, 2013, locating them south of Clendening Lake near the town of Uhrichsville, Ohio. A subsequent analysis identified 190 earthquakes during a 39-hour period on Oct. 1 and 2, just hours after hydraulic fracturing began on one of the wells.

The micro-seismicity varied, corresponding with the fracturing activity at the wells. The timing of the earthquakes, along with their tight linear clustering and similar waveform signals, suggest a unique source for the cause of the earthquakes -- the hydraulic fracturing operation. The fracturing likely triggered slip on a pre-existing fault, though one that is located below the formation expected to confine the fracturing, according to the authors.

"As hydraulic fracturing operations explore new regions, more seismic monitoring will be needed since many faults remain unmapped." Friberg co-authored the paper with Ilya Dricker, also with ISTI, and Glenda Besana-Ostman originally with Ohio Department of Natural Resources, and now with the Bureau of Reclamation at the U.S. Department of Interior.

Source: Seismological Society of America

Read More

Fracking: Gas leaks from faulty wells linked to contamination in some groundwater

As researchers study hydraulic fracturing, a team led by Thomas Darrah at The Ohio State University has identified a key source of groundwater contamination (labeled 5, center right) caused by faulty well casings.
Credit: Image courtesy of Thomas Darrah, The Ohio State University

A study has pinpointed the likely source of most natural gas contamination in drinking-water wells associated with hydraulic fracturing, and it's not the source many people may have feared.

What's more, the problem may be fixable: improved construction standards for cement well linings and casings at hydraulic fracturing sites.

A team led by a researcher at The Ohio State University and composed of researchers at Duke, Stanford, Dartmouth, and the University of Rochester devised a new method of geochemical forensics to trace how methane migrates under the earth. The study identified eight clusters of contaminated drinking-water wells in Pennsylvania and Texas.

Most important among their findings, published this week in the Proceedings of the National Academy of Sciences, is that neither horizontal drilling nor hydraulic fracturing of shale deposits seems to have caused any of the natural gas contamination.

"There is no question that in many instances elevated levels of natural gas are naturally occurring, but in a subset of cases, there is also clear evidence that there were human causes for the contamination," said study leader Thomas Darrah, assistant professor of earth sciences at Ohio State. "However our data suggests that where contamination occurs, it was caused by poor casing and cementing in the wells," Darrah said.

In hydraulic fracturing, water is pumped underground to break up shale at a depth far below the water table, he explained. The long vertical pipes that carry the resulting gas upward are encircled in cement to keep the natural gas from leaking out along the well. The study suggests that natural gas that has leaked into aquifers is the result of failures in the cement used in the well.

"Many of the leaks probably occur when natural gas travels up the outside of the borehole, potentially even thousands of feet, and is released directly into drinking-water aquifers" said Robert Poreda, professor of geochemistry at the University of Rochester.

"These results appear to rule out the migration of methane up into drinking water aquifers from depth because of horizontal drilling or hydraulic fracturing, as some people feared," said Avner Vengosh, professor of geochemistry and water quality at Duke.

"This is relatively good news because it means that most of the issues we have identified can potentially be avoided by future improvements in well integrity," Darrah said.

"In some cases homeowner's water has been harmed by drilling," said Robert B. Jackson, professor of environmental and earth sciences at Stanford and Duke. "In Texas, we even saw two homes go from clean to contaminated after our sampling began."

The method that the researchers used to track the source of methane contamination relies on the basic physics of the noble gases (which happen to leak out along with the methane). Noble gases such as helium and neon are so called because they don't react much with other chemicals, although they mix with natural gas and can be transported with it.

That means that when they are released underground, they can flow long distances without getting waylaid by microbial activity or chemical reactions along the way. The only important variable is the atomic mass, which determines how the ratios of noble gases change as they tag along with migrating natural gas. These properties allow the researchers to determine the source of fugitive methane and the mechanism by which it was transported into drinking water aquifers.

The researchers were able to distinguish between the signatures of naturally occurring methane and stray gas contamination from shale gas drill sites overlying the Marcellus shale in Pennsylvania and the Barnett shale in Texas.

The researchers sampled water from the sites in 2012 and 2013. Sampling sites included wells where contamination had been debated previously; wells known to have naturally high level of methane and salts, which tend to co-occur in areas overlying shale gas deposits; and wells located both within and beyond a one-kilometer distance from drill sites.

As hydraulic fracturing starts to develop around the globe, including countries South Africa, Argentina, China, Poland, Scotland, and Ireland, Darrah and his colleagues are continuing their work in the United States and internationally. And, since the method that the researchers employed relies on the basic physics of the noble gases, it can be employed anywhere. Their hope is that their findings can help highlight the necessity to improve well integrity.

Source: Ohio State University

Read More

Residual hydraulic fracturing water not a risk to groundwater

Sixty-one minutes of imbibition and evaporation of a 154 microliter bead of tap water on a 2.3 gram chip of the Union Springs Member of the Marcellus Formation. The drop disappeared in approximately 100 minutes. The photograph labeled 0 min was taken about 10 seconds after the bead was dropped on the Marcellus chip. Counter-current imbibition is indicated by methane bubbles floating up into the water bead from the Marcellus chip, starting on the left side of the bead at time = 0 min. This experiment was started 5 days after receiving fresh cuttings of the Union Springs from a horizontal well in PA.
Credit: Engelder, Penn State

Hydraulic fracturing -- fracking or hydrofracturing -- raises many concerns about potential environmental impacts, especially water contamination. Currently, data show that the majority of water injected into wells stays underground, triggering fears that it might find its way into groundwater. New research by a team of scientists should help allay those fears.

In a paper published in the current issue of the Journal of Unconventional Oil and Gas Resources, Terry Engelder, professor of geosciences, Penn State; Lawrence Cathles, professor of earth and atmospheric sciences, Cornell University; and Taras Bryndzia, geologist, Shell International Exploration and Production Inc., report that injected water that remains underground is sequestered in the rock formation and therefore does not pose a serious risk to water supplies.

Hydraulic fracturing is a drilling technique commonly used to extract gas from previously inaccessible "tight" gas reserves, including gas trapped in shale formations such as the Marcellus. During this technique between 1.2 and 5 million gallons of water mixed with sand and chemical additives are injected at high pressure into each well to fracture the rock and release the gas.

Typically less than half of the injected water returns to the surface as "flowback" or, later, production brine, and in many cases recovery is less than 30 percent. In addition to the chemical additives, flowback water contains natural components of the gas shale including salt, some metals, and radionuclides and could impair water quality if released without proper treatment. While flowback water can be managed and treated at the surface, the fate of the water left in place, called residual treatment water or RTW, was previously uncertain.

Some have suggested that RTW may be able to flow upward along natural pathways, mainly fractures and faults, and contaminate overlying groundwater. Others have proposed that natural leakage of the Marcellus is occurring without human assistance through high-permeability fractures connecting the Marcellus directly to the water table and that hydraulic fracturing could worsen this situation.

The researchers report that ground water contamination is not likely because contaminant delivery rate would be too small even if leakage were possible, but more importantly, upward migration of RTW is not plausible due to capillary and osmotic forces that propel RTW into, not out of, the shale. Their study indicates that RTW will be stably retained within the shale formation due to multiphase capillary phenomena.

"Capillary forces and coupled diffusion-osmosis processes are the reasons the brines and the RTW are not free to escape from gas shale," said Engelder. "The most direct evidence of these forces is the observation that more than half the treatment waters are not recovered. Introducing treatment water causes gas shale to act like a sponge based on the principles of imbibition.

"Imbibition into gas shale is made possible by the high capillary suction that a fine-grained, water-wet shale matrix can exert on water. As water is wicked into gas shale, the natural gas in the shale is pushed out. The capillary forces that suck the RTW into the gas shale keep it there."

Estimating imbibition is complicated, but simple experiments conducted by the researchers show that water can be readily imbibed into gas shale in quantities fully capable of sequestering RTW. The researchers demonstrated this process in a series of experiments on cuttings recovered from the Union Springs Member of the Marcellus gas shale in Pennsylvania and on core plugs of Haynesville gas shale from NW Louisiana.

"The hydraulic fracturing fluid consists mostly of very low-salinity surface water, while the shale contains high concentrations of water soluble inorganic cations and anions," said Engelder. "During hydraulic fracturing water is lost to the formation while inorganic cations and anions are transferred from the formation to the hydraulic fracture. Diffusion osmosis assists the rapid imbibition of water by the shale and diffusion of ions into the treatment water causing the high salinities observed in flowback fluids. The point to be emphasized here is that this osmotic pressure pushes the hydraulic fracture fluids into the shale matrix, expelling gas and cations to make high-salinity flowback in the process."

The researchers believe that in addition to there not being enough water in the shale to contaminate groundwater, the most important point of their work is that multiphase capillary phenomena must be considered in cases where a non-aqueous fluid is present in the subsurface pore space. The vadose zone -- the area from the surface to the groundwater -- and oil and gas migration cannot be understood using single-phase, porous-media flow methods, and any policy insights or prescriptions based on single-phase considerations will be fatally flawed, they argue.

"The practical implication is that hydrofracture fluids will be locked into the same 'permeability jail' that sequestered overpressured gas for over 200 million years," said Engelder. "If one wants to dispose of fracking waters, one could probably not choose a safer way to do so than to inject them into a gas shale."

Source: Penn State

Read More

A new look at what's in 'fracking' fluids raises red flags: Some compounds toxic to mammals

Scientists are getting to the bottom of what’s in fracking fluids — with some troubling results.
Credit: Doug Duncan/U.S. Geological Survey

As the and gas drilling technique called hydraulic fracturing (or "fracking") proliferates, a new study on the contents of the fluids involved in the process raises concerns about several ingredients. The scientists presenting the work today at the 248th National Meeting & Exposition of the American Chemical Society (ACS) say that out of nearly 200 commonly used compounds, there's very little known about the potential health risks of about one-third, and eight are toxic to mammals.

William Stringfellow, Ph.D., says he conducted the review of fracking contents to help resolve the public debate over the controversial drilling practice. Fracking involves injecting water with a mix of chemical additives into rock formations deep underground to promote the release of oil and gas. It has led to a natural gas boom in the U.S., but it has also stimulated major opposition and troubling reports of contaminated well water, as well as increased air pollution near drill sites.

"The industrial side was saying, 'We're just using food additives, basically making ice cream here,'" Stringfellow says. "On the other side, there's talk about the injection of thousands of toxic chemicals.

As scientists, we looked at the debate and asked, 'What's the real story?'"
To find out, Stringfellow's team at Lawrence Berkeley National Laboratory and University of the Pacific scoured databases and reports to compile a list of substances commonly used in fracking. They include gelling agents to thicken the fluids, biocides to keep microbes from growing, sand to prop open tiny cracks in the rocks and compounds to prevent pipe corrosion.

What their analysis revealed was a little truth to both sides' stories -- with big caveats. Fracking fluids do contain many nontoxic and food-grade materials, as the industry asserts. But if something is edible or biodegradable, it doesn't automatically mean it can be easily disposed of, Stringfellow notes.
"You can't take a truckload of ice cream and dump it down the storm drain," he says, building on the industry's analogy. "Even ice cream manufacturers have to treat dairy wastes, which are natural and biodegradable. They must break them down rather than releasing them directly into the environment."
His team found that most fracking compounds will require treatment before being released. And, although not in the thousands as some critics suggest, the scientists identified eight substances, including biocides, that raised red flags. These eight compounds were identified as being particularly toxic to mammals.

"There are a number of chemicals, like corrosion inhibitors and biocides in particular, that are being used in reasonably high concentrations that potentially could have adverse effects," Stringfellow says. "Biocides, for example, are designed to kill bacteria -- it's not a benign material."

They're also looking at the environmental impact of the fracking fluids, and they are finding that some have toxic effects on aquatic life.

In addition, for about one-third of the approximately 190 compounds the scientists identified as ingredients in various fracking formulas, the scientists found very little information about toxicity and physical and chemical properties.

"It should be a priority to try to close that data gap," Stringfellow says.
He acknowledges funding from the University of the Pacific, the Bureau of Land Management and the state of California.

Source: American Chemical Society (ACS)

Read More

Acid mine drainage reduces radioactivity in fracking waste

“Fracking wastewater and acid mine drainage each pose well-documented environmental and public health risks. But in laboratory tests, we found that by blending them in the right proportions we can bind some of the fracking contaminants into solids that can be removed before the water is discharged back into streams and rivers,” said Avner Vengosh.
 Credit: Duke University

Much of the naturally occurring radioactivity in fracking wastewater might be removed by blending it with another wastewater from acid mine drainage, according to a Duke University-led study.

"Fracking wastewater and acid mine drainage each pose well-documented environmental and public health risks. But in laboratory tests, we found that by blending them in the right proportions we can bind some of the fracking contaminants into solids that can be removed before the water is discharged back into streams and rivers," said Avner Vengosh, professor of geochemistry and water quality at Duke's Nicholas School of the Environment.

"This could be an effective way to treat Marcellus Shale hydraulic fracturing wastewater, while providing a beneficial use for acid mine drainage that currently is contaminating waterways in much of the northeastern United States," Vengosh said. "It's a win-win for the industry and the environment."
Blending fracking wastewater with acid mine drainage also could help reduce the depletion of local freshwater resources by giving drillers a source of usable recycled water for the hydraulic fracturing process, he added.

"Scarcity of fresh water in dry regions or during periods of drought can severely limit shale gas development in many areas of the United States and in other regions of the world where fracking is about to begin," Vengosh said. "Using acid mine drainage or other sources of recycled or marginal water may help solve this problem and prevent freshwater depletion."

The peer-reviewed study was published in late December 2013 in the journal Environmental Science & Technology.

In hydraulic fracturing -- or fracking, as it is sometimes called -- millions of tons of water are injected at high pressure down wells to crack open shale deposits buried deep underground and extract natural gas trapped within the rock. Some of the water flows back up through the well, along with natural brines and the natural gas. This "flowback fluid" typically contains high levels of salts, naturally occurring radioactive materials such as radium, and metals such as barium and strontium.

A study last year by the Duke team showed that standard treatment processes only partially remove these potentially harmful contaminants from Marcellus Shale wastewater before it is discharged back into streams and waterways, causing radioactivity to accumulate in stream sediments near the disposal site.

Acid mine drainage flows out of abandoned coal mines into many streams in the Appalachian Basin. It can be highly toxic to animals, plants and humans, and affects the quality of hundreds of waterways in Pennsylvania and West Virginia.

Because much of the current Marcellus shale gas development is taking place in regions where large amounts of historic coal mining occurred, some experts have suggested that acid mine drainage could be used to frack shale gas wells in place of fresh water.

To test that hypothesis, Vengosh and his team blended different mixtures of Marcellus Shale fracking wastewater and acid mine drainage, all of which were collected from sites in western Pennsylvania and provided to the scientists by the industry.

After 48 hours, the scientists examined the chemical and radiological contents of 26 different mixtures. Geochemical modeling was used to simulate the chemical and physical reactions that had occurred after the blending; the results of the modeling were then verified using x-ray diffraction and by measuring the radioactivity of the newly formed solids.

"Our analysis suggested that several ions, including sulfate, iron, barium and strontium, as well as between 60 and 100 percent of the radium, had precipitated within the first 10 hours into newly formed solids composed mainly of strontium barite," Vengosh said. These radioactive solids could be removed from the mixtures and safely disposed of at licensed hazardous-waste facilities, he said. The overall salinity of the blended fluids was also reduced, making the treated water suitable for re-use at fracking sites.

"The next step is to test this in the field. While our laboratory tests show that is it technically possible to generate recycled, treated water suitable for hydraulic fracturing, field-scale tests are still necessary to confirm its feasibility under operational conditions," Vengosh said.

Source: Duke University

Read More