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

SESAME light source brings second beamline into service

Allan, Jordan, 30 April 2018. At 11:21 pm local time (GMT +3) scientists at the SESAME light source brought the laboratory’s infrared (IR) spectromicroscopy beamline into service for the first time.

This beamline is a completely new beamline. It was designed and built in collaboration with the French Soleil Synchrotron. It is SESAME’s second operational beamline, and it joins an X-ray beamline that saw first light on 23 November 2017. The addition of the IR beamline will enable the application of infrared microspectroscopy and imaging in a wide range of fields, including surface and materials science (e.g. characterization of new nanomaterials for solar cell fabrication and for drug delivery mechanisms), biochemistry, archaeology, geology, cell biology, biomedical diagnostics and environmental science (e.g. air and water pollution)

“I’ve been waiting a long time for this moment,” said Gihan Kamel, SESAME’s IR beamline scientist. “It’s very satisfying to see light in the beamline, and to be able to start doing research here that we previously had to travel to Europe to carry out.”

In preparation for the SESAME research programme, a number of thematic schools are being held across the region in a collaboration involving SESAME and European partners including the European Union through its Open SESAME project. One of these was held at SESAME earlier this month, covering science on the IR beamline. Students came from across the region and learned techniques ranging from sample preparation to data analysis.

“The infrared beamline has a mouth-watering research programme lined up,” said SESAME Scientific Director Giorgio Paolucci, “and it is great to see so many young people from across the region preparing to embark on careers in science.”

>Read more on the SESAME website

Gold protein clusters could be used as environmental and health detectors

Peng Zhang and his collaborators study remarkable, tiny self-assembling clusters of gold and protein that glow a bold red. And they’re useful: protein-gold nanoclusters could be used to detect harmful metals in water or to identify cancer cells in the body.
“These structures are very exciting but are very, very hard to study. We tried many different tools, but none worked,” says Zhang, a Dalhousie University professor.

Peng Zhang and his collaborators study remarkable, tiny self-assembling clusters of gold and protein that glow a bold red. And they’re useful: protein-gold nanoclusters could be used to detect harmful metals in water or to identify cancer cells in the body.

“These structures are very exciting but are very, very hard to study. We tried many different tools, but none worked,” says Zhang, a Dalhousie University professor.

>Read more on the Canadian Light Source website

Image: The protein-gold structure. The protein, which both builds and holds in place the gold cluster, is shown in grey.

Cooking oil and clouds

The complex behaviour of atmospheric aerosols has implications for climate change researc

According to the Intergovernmental Panel on Climate Change (IPCC), the increase in atmospheric aerosols and clouds since pre-Industrial times is one of the largest sources of uncertainty in climate change. Aerosol emissions from cooking are not currently included in European emission figures, yet recent research1 suggests that they contribute nearly 10% of human-related emissions of small particulate matter (PM2.5) in the UK. Now research carried out at Diamond, MAX-lab in Sweden, the University of Bath and the University of Reading published in Nature Communications has demonstrated that atmospheric aerosols can form complex 3D structures, with important implications for their role in climate change.

The work is a collaboration between the atmospheric scientist Dr Christian Pfrang and the biophysical chemist Dr Adam Squires.

>Read more on the diamond website or the MAX-IV website

Image: A levitated droplet at MAX-lab.

Researchers explore ways to remove antibiotics polluting lakes and rivers

Pre-treated barley straw is showing promise as an environmentally-friendly material.

Pre-treated barley straw could be used to help soak up certain types of antibiotics polluting waterways. Pharmaceuticals, including antibiotics, are an increasingly common pollutant in water systems, says Catherine Hui Niu, associate professor in the Department of Chemical and Biological Engineering at the University of Saskatchewan.

After pharmaceuticals are used in humans and animals, traces are excreted and end up in sewage and, from there, into the environment. Their presence in waterways has raised concerns about potential risks to human health and ecosystems. To date there has been no effective way to remove them from water sources.

There are some materials that attract pharmaceutical pollutants to them in a process called adsorption, and could hypothetically be used to help remove them from water, says Niu. But their adsorption capacities need to be enhanced to make them useful for large scale clean-up efforts.

Improving the treatment of industrial waste

Research uncovers the mechanism of memory effect of lamellar double hydroxides (LDH).

Synthetic dyes are in constant use in a wide variety of industries, from textile to cosmetics. Both the production and use of these substances can lead to environmental problems if they are not properly degraded or removed from industrial effluents. Among the many physical, chemical or biological processes that can be used for the treatment of such wastes, the adsorption processes are noteworthy for combining low cost and high removal rates.

R. M. M. Santos et al. [1] used the LNLS facilities to investigate the properties of lamellar double hydroxides (LDH), a family of anionic clays with high adsorption capacity, for the removal of synthetic dyes.

Researchers develop technique to reuse carbon dioxide and methane, slowing climate change

Reusing carbon dioxide (CO2) and methane waste emissions from industrial sources is closer to reality.

And this  thanks to recent findings from a project conducted at the Canadian Light Source and the University of Saskatchewan. CO2 and methane are the most significant greenhouse gases resulting from human activity, says Dr. Hui Wang, professor in the Department of Chemical and Biological Engineering at the University of Saskatchewan.

Capturing CO2 and methane emissions from industrial sources and reusing them could reduce the threat on the world’s ecosystem by slowing climate change, says Dr. Wang, the principal researcher of a paper published in Catalyst Today.

CO2 and methane can be triggered to undergo chemical reactions with each other to create synthesis gas or syngas. Syngas is a mixture of carbon monoxide and hydrogen, which can be used to synthesize a variety of liquid fuels or ammonia.

This reaction between CO2 and methane, also called ‘dry reforming of methane’, has not been fully scaled-up for commercial use due to lack of an inexpensive and industrially viable catalyst. Catalysts are used to speed up chemical reactions.