Riverine iron survives salty exit to sea

Iron organic complexes in Sweden’s boreal rivers significantly contribute to increased iron concentration in open marine waters, X-ray spectroscopy data shows. A Lund University study in Biogeosciences characterizes the role of salinity for iron-loading in estuarine zones, a factor which underpins intensifying seasonal algal blooms in the Baltic Sea.

The study ties in with a reported trend of increased riverine iron concentrations over the last decade in North America, northern Europe and in particular, Swedish and Finnish rivers. This, in conjunction with a predicted rise in extreme weather events in Scandinavia due to climate change, provides momentum for more bioavailable iron to enter marine environments such as the Baltic Sea.

“The consequences of increasing riverine iron for the receiving [marine] system depend first and foremost on the fate of iron in the estuarine salinity gradient. We had questions on what factors determine the movement and transport capacity of iron in these boreal rivers,” said Simon Herzog, postdoctoral researcher at Lund University.

The research group investigated the iron discharge in eight boreal rivers in Sweden which drain into the Baltic Sea, a brackish marine system. Water samples were taken upstream and at the river mouths, the latter just before estuarine mixing and stronger saline conditions occur. Spring and autumn specimens enabled the comparative analysis of flow conditions. To determine the type and amounts of iron species, measurements with X-ray absorbance spectroscopy (XAS) were taken at beamline I811 at Max-lab in Lund, Sweden and X-ray Absorption Near-Edge Structure (XANES) spectra at beamline ID26 at the European Synchrotron Radiation Facility (ESRF) in Grenoble, France.

Read more on the MAX IV website

Image: A view of the Ore River in northern Sweden

Credit: Simon Herzog

Building knowledge of changes in uranium chemistry

ANSTO’s considerable expertise in characterising uranium-containing compounds has contributed to a new systematic investigation of the origins of atomic structural distortions in a family of actinide compounds.

These compounds are known as rutile-related mixed metal ternary (three-part) uranium oxides. Rutile refers to mineral compounds composed primarily of titanium dioxide.

In research published in Inorganic Chemistry, a large team of researchers used both neutron and synchrotron radiation and theoretical calculations to establish systematically precise and accurate crystal structures and uranium oxidation states in the rutile-related mixed metal ternary uranium oxide systems.

Read more on the ANSTO website

Image:  Dr Zhaoming Zhang, Principal Research Scientist, Nuclear Fuel Cycle, ANSTO

Credit: ANSTO

Out of the blue: X-rays shed light on on ultramarine blue in masterpieces

According to a survey led by Nature in 2016, 70% of scientists admitted they could not reproduce another scientist’s experiments and more than half could not reproduce their own. In order to improve sharing and, in turn, enhancing innovation, the European Union is working on implementing the European Open Science Cloud (EOSC), a kind of “library” of all experimental raw data and methods, available to everyone.

The ESRF is doing its bit by leading the PaNOSC (Photon and Neutron Open Science Cloud) project: “We are in the process of implementing the ESRF Data Policy to organise the data from experiments in an archive, which ultimately everyone will be able to access. The scientific teams will have three years to keep their data closed to the public, and after that any other scientist can try to repeat or do new data analysis of the very same experiment if he or she wishes to”, explains Andy Götz, coordinator of the project. The final goal of PaNOSC and the EOSC is to make data from publicly funded research in Europe Findable, Accessible, Interoperable and Reusable (FAIR).

>Read more on the ESRF website

Image: Alessa Gambardella at a stereomicroscope looking at ultramarine blue in Hendrick per Brugghen’s The Adoration of the Kings (1619)

Credit: Courtesy of Department of Conservation & Science, Rijksmuseum.

Plant roots police toxic pollutants

X-ray studies reveal details of how P. juliflora shrub roots scavenge and immobilize arsenic from toxic mine tailings.

Working in collaboration with scientists at the U.S. Department of Energy’s Brookhaven National Laboratory and SLAC National Accelerator Laboratory, researchers at the University of Arizona have identified details of how certain plants scavenge and accumulate pollutants in contaminated soil. Their work revealed that plant roots effectively “lock up” toxic arsenic found loose in mine tailings—piles of crushed rock, fluid, and soil left behind after the extraction of minerals and metals. The research shows that this strategy of using plants to stabilize pollutants, called phytostabilization, could even be used in arid areas where plants require more watering, because the plant root activity alters the pollutants to forms that are unlikely to leach into groundwater.

The Arizona based researchers were particularly concerned with exploring phytostabilization strategies for mining regions in the southwestern U.S., where tailings can contain high levels of arsenic, a contaminant that has toxic effects on humans and animals. In the arid environment with low levels of vegetation, wind and water erosion can carry arsenic and other metal pollutants to neighboring communities.

>Read more on the National Synchrotron Light Source II (NSLS-II) website

Image: Scientists from the University of Arizona collect plant samples from the mine tailings at the Iron King Mine and Humboldt Smelter Superfund site in central Arizona. X-ray studies at Brookhaven Lab helped reveal how these plants’ roots lock up toxic forms of arsenic in the soil.
Credit: Jon Chorover