. Scientific Frontline

Tuesday, December 13, 2022

Methane from manholes and historic landfills: significant sources of gas go unrecognized

Montreal’s municipal greenhouse gas inventory presents an incomplete picture of methane emissions
Photo Credit: Mohammad Rezaie

Cities are responsible for almost 1/5th of the global methane emissions caused by human activities. But most cities don’t capture information about the full range of sources of this powerful greenhouse gas. In 2020, a team led by McGill University, measured methane emissions from various sources across the city of Montreal. The researchers found that two of the four most important sources of methane emissions in the city (historic landfills and manholes) are not included in the city’s municipal greenhouse gas inventories, making it difficult to tackle the problem fully, or reach the city’s goal of being carbon neutral by 2050.

The study provides the first set of direct measurements of methane emissions in Montreal and in the province of Quebec.

The study provides detailed and specific measurements of methane emissions by source – such as the type of manhole or the type of natural gas infrastructure. The results, which highlight the importance of gathering information about the specific sources of methane emissions to set in place mitigation strategies that are adapted to each specific situation should be of interest not only to researchers across Canada and around the world but also to policy makers.

Pollution cleanup method destroys toxic “forever chemicals”

Ultraviolet light used for water treatment 
Photo Credit: UCR/Liu Lab

An insidious category of carcinogenic pollutants known as “forever chemicals” may not be so permanent after all.

University of California, Riverside, chemical engineering and environmental scientists recently published new methods to chemically break up these harmful substances found in drinking water into smaller compounds that are essentially harmless.

The patent-pending process infuses contaminated water with hydrogen, then blasts the water with high-energy, short-wavelength ultraviolet light. The hydrogen polarizes water molecules to make them more reactive, while the light catalyzes chemical reactions that destroy the pollutants, known as PFAS or poly- and per-fluoroalkyl substances.

This one-two punch breaks the strong fluorine-to-carbon chemicals bonds that make these pollutants so persistent and accumulative in the environment. In fact, the molecular destruction of PFAS increased from 10% to nearly 100% when compared to other ultraviolet water-treatment methods, while no other undesirable byproducts or impurities are generated, the UCR scientists reported in a paper recently published in the Journal of Hazardous Materials Letters.

Surveilling carbon sequestration: A smart collar to sense leaks

Sandia National Laboratories’ smart collar detecting a leak from a carbon dioxide storage reservoir.
 Animation Credit: Max Schwaber

Sandia National Laboratories engineers are working on a device that would help ensure captured carbon dioxide stays deep underground — a critical component of carbon sequestration as part of a climate solution.

Carbon sequestration is the process of capturing CO2 — a greenhouse gas that traps heat in the Earth’s atmosphere — from the air or where it is produced and storing it underground. However, there are some technical challenges with carbon sequestration, including making sure that the CO2 remains underground long term. Sandia’s wireless device pairs with tiny sensors to monitor for CO2 leaks and tell above-ground operators if one happens — and it lasts for decades.

“The world is trying a whole lot of different ways to reduce the production of CO2 to mitigate climate change,” said Andrew Wright, Sandia electrical engineer and project lead. “A complementary approach is to reduce the high levels of CO2 in the atmosphere by collecting a good chunk of it and storing it deep underground. The technology we’re developing with the University of Texas at Austin aims to determine whether the CO2 stays down there. What is special about this technology is that we’ll be monitoring it wirelessly and thus won’t create another potential path for leakage like a wire or fiber.”

Good vibrations turbo charge green hydrogen production

PhD researcher Yemima Ehrnst holding the acoustic device the research team used to boost hydrogen production, through electrolysis to split water.
Photo Credit: RMIT University

They say their invention offers a promising way to tap into a plentiful supply of cheap hydrogen fuel for transportation and other sectors, which could radically reduce carbon emissions and help fight climate change.

By using high-frequency vibrations to “divide and conquer” individual water molecules during electrolysis, the team managed to split the water molecules to release 14 times more hydrogen compared with standard electrolysis techniques.

Electrolysis involves electricity running through water with two electrodes to split water molecules into oxygen and hydrogen gases, which appear as bubbles. This process produces green hydrogen, which represents just a small fraction of hydrogen production globally due to the high energy required.

Most hydrogen is produced from splitting natural gas, known as blue hydrogen, which emits greenhouse gases into the atmosphere.

UH lab produces building blocks to DNA and RNA in deep space

Conceptualization of the role of methanediamine in the galactic cosmic ray mediated synthesis of DNA and RNA bases in deep space.
Illustration Credit: University of Hawaiʻi

The synthetic production of a critical building block called methanediamine for the first time by researchers in University of Hawaiʻi at Mānoa’s Department of Chemistry could lead to key insights into the origins of life. The researchers have discovered a method to produce it in a lab under conditions that mimic icy interstellar nanoparticles in cold molecular clouds in space.

Nitrogen is the most abundant element in Earth’s atmosphere. It is also incorporated into nearly one-third of some 300 molecules identified in the interstellar medium, which is the material that exists in the space between the stars in a galaxy.

Most nitrogen-containing molecules in deep space carry exclusively the nitrile moiety (organic compound that has a carbon, nitrogen functional group), while amines (a member of a family of nitrogen-containing organic compounds that is derived from ammonia) and imines (compounds containing a carbon-nitrogen double bond) are relatively rare. According to experts, an understanding of the origin of these less common molecule parts in deep space is central to the hypothesis for the origin of life because all nucleobases (nitrogen-containing compounds) found in contemporary RNA and DNA contain amines and imines.

Monday, December 12, 2022

Princeton chemists create quantum dots at room temp using lab-designed protein


Nature uses 20 canonical amino acids as building blocks to make proteins, combining their sequences to create complex molecules that perform biological functions.

But what happens with the sequences not selected by nature? And what possibilities lie in constructing entirely new sequences to make novel, or de novo, proteins bearing little resemblance to anything in nature?

That’s the terrain where Michael Hecht, professor of chemistry, works with his research group. And recently, their curiosity for designing their own sequences paid off.

They discovered the first known de novo (newly created) protein that catalyzes, or drives, the synthesis of quantum dots. Quantum dots are fluorescent nanocrystals used in electronic applications from LED screens to solar panels.

Their work opens the door to making nanomaterials in a more sustainable way by demonstrating that protein sequences not derived from nature can be used to synthesize functional materials — with pronounced benefits to the environment.

True giant wombat gives Diprotodon podium a wobble

Ramsayia reconstruction (r) next to a modern wombat.
Illustration Credit: Eleanor Pease, CC BY-NC

If you thought Australia was home to only one ancient ‘giant wombat’, think again.

While the Diprotodon – the extinct megafauna species that is distantly related to wombats but was the size of a small car – is commonly (but incorrectly) thought of as Australia’s ‘giant wombat’, researchers from Griffith University have shed light on a large species that does belong in the modern-day wombat family.

The complete skull of this true fossil giant wombat, found in a Rockhampton cave in Queensland and estimated to be around 80,000 years old, has been described for the first time by a team led by Associate Professor Julien Louys from Griffith’s Australian Research Centre for Human Evolution.

Precise solar observations fed millions in ancient Mexico

Rising sun Mount Tlaloc in Mexico.
Photo Credit: Ben Meissner

Without clocks or modern tools, ancient Mexicans watched the sun to maintain a farming calendar that precisely tracked seasons and even adjusted for leap years.

Before the Spanish arrival in 1519, the Basin of Mexico’s agricultural system fed a population that was extraordinarily large for the time. Whereas Seville, the largest urban center in Spain, had a population of fewer than 50,000, the Basin, now known as Mexico City, was home to as many as 3 million people.

To feed so many people in a region with a dry spring and summer monsoons required advanced understanding of when seasonal variations in weather would arrive. Planting too early, or too late, could have proved disastrous. The failure of any calendar to adjust for leap-year fluctuations could also have led to crop failure.

Though colonial chroniclers documented the use of a calendar, it was not previously understood how the Mexica, or Aztecs, were able to achieve such accuracy. New UC Riverside research, published in the Proceedings of the National Academy of Sciences, demonstrates how they did it. They used the mountains of the Basin as a solar observatory, keeping track of the sunrise against the peaks of the Sierra Nevada mountains.

“We concluded they must have stood at a single spot, looking eastwards from one day to another, to tell the time of year by watching the rising sun,” said Exequiel Ezcurra, distinguished UCR professor of ecology who led the research.

SwRI Study Describes First Ultraviolet Imaging of Sun's Middle Corona

Video Credit: Courtesy of SwRI/NOAA A

A team of researchers from Southwest Research Institute (SwRI), NASA and the Max Planck Institute for Solar System Research (MPS) have discovered web-like plasma structures in the Sun’s middle corona. The researchers describe their innovative new observation method, imaging the middled corona in ultraviolet (UV) wavelength, in a new study published in Nature Astronomy. The findings could lead to a better understanding of the solar wind’s origins and its interactions with the rest of the solar system.

Since 1995, the U.S. National Oceanic and Atmospheric Administration has observed the Sun’s corona with the Large Angle and Spectrometric Coronagraph (LASCO) stationed aboard the NASA and European Space Agency Solar and Heliospheric Observatory (SOHO) spacecraft to monitor space weather that could affect the Earth. But LASCO has a gap in observations that obscures our view of the middle solar corona, where the solar wind originates.

Researcher takes aim at turning yellow into green by recycling urine

Urine recycling is the goal of WVU researcher Kevin Orner’s study of a wastewater treatment system that can attach directly to a toilet, extracting valuable nutrients used as fertilizers.
Illustration Credit: Sheree Wentz / West Virginia University

The waste flushed down toilets could be a valuable source of resources and profits — and easier on the environment, according to a West Virginia University engineer’s research.

Kevin Orner, a Benjamin M. Statler College of Engineering and Mineral Resources assistant professor is developing a technology that can treat urine on site rather than at a remote, centralized wastewater treatment facility. The technology could reside underneath a toilet, enabling urine treatment to happen quickly and promoting the recovery of nitrogen, a nutrient that can be sold as a fertilizer.

Orner’s findings, published in the journal Environmental Technology, make urine recycling more feasible in terms of integration into existing infrastructure and could reduce the amount of nutrients that enter lakes and rivers. Excessive nutrient discharge can put aquatic ecosystems at risk by promoting the growth of algae that consume dissolved oxygen in the water.

The goal is to transform waste collection and treatment from an environmentally harmful service that costs money to an environmentally beneficial service that makes money.

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