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New Electrochemical Method Eliminates Mercury From Water

In the laboratory of Wickman and Tunsu at the Chalmers University of Technology, when mercury ions (light purple) in a liquid come near an electrode of platinum, they are attracted to the electrode's surface where they get reduced to metallic mercury. On the electrode, mercury atoms (dark purple) and platinum atoms (grey) develop into a very strong alloy, and so the mercury is removed from the water. 2018 (Photo by Björn Wickman and Adam Arvidsson / Chalmers University of Technology) Posted for media use.

In the laboratory of Wickman and Tunsu at the Chalmers University of Technology, when mercury ions (light purple) in a liquid come near an electrode of platinum, they are attracted to the electrode’s surface where they get reduced to metallic mercury. On the electrode, mercury atoms (dark purple) and platinum atoms (grey) develop into a very strong alloy, and so the mercury is removed from the water. 2018 (Photo by Björn Wickman and Adam Arvidsson / Chalmers University of Technology) Posted for media use.

By Sunny Lewis

GOTEBORG, Sweden, December 6, 2018 (Maximpact.com News) – Water contaminated with mercury and other toxic heavy metals is a major cause of environmental damage and health problems worldwide. Now, researchers at Sweden’s Chalmers University of Technology have devised a new way to clean contaminated water – through an electrochemical process.

“Our results have really exceeded the expectations we had when we started with the technique,” says the research leader Björn Wickman, from Chalmers’ Department of Physics. “Our new method makes it possible to reduce the mercury content in a liquid by more than 99 percent. This can bring the water well within the margins for safe human consumption.”

The World Health Organization says mercury is one the most harmful substances for human health. It accumulates in the body and can harm the brains, hearts, kidneys, lungs and immune systems of people of all ages. Mercury is especially harmful to unborn children and infants whose nervous systems are under development, and it can be transmitted from a mother to a child during pregnancy.

The toxic metal spreads easily through nature and can enter the food chain. Freshwater fish, for example, often contain high levels of mercury.

Mercury is a naturally occurring element that can be released to the environment from natural sources – the weathering of rocks containing mercury, forest fires, volcanic eruptions or geothermal activities – and also from human activities.

Humans use mercury in industrial processes that produce chlorine or polyvinyl chloride (PVC), and polyurethane elastomers. It is extensively used to extract gold from ore in artisanal and small-scale gold mining. It is in products such as electrical switches and thermostats, relays, measuring and control equipment, energy-efficient fluorescent light bulbs, batteries and dental amalgam.

It is also used in laboratories, cosmetics, pharmaceuticals, in vaccines as a preservative, in paints and jewelry. Discarded electronics often contain mercury and can end up being salvaged by unprotected workers in developing countries.

Mercury is also released from industrial processes, such as coal-fired power and heat generation, cement production, mining and other metallurgic activities such as non-ferrous metals production, as well as from incineration of many types of waste.

An estimated 5,500-8,900 tons of mercury is currently emitted and re-emitted each year to the atmosphere.

Today there are strict regulations concerning the management of toxic heavy metals to limit their spread in nature. But many places worldwide are already contaminated, and the metals can be transported in rain or in the air. This results in ecosystems where heavy metals can become abundant.

“Today, cleaning away the low, yet harmful, levels of mercury from large amounts of water is a major challenge. Industries need better methods to reduce the risk of mercury being released in nature,” says Wickman.

Björn Wickman and Cristian Tunsu are presenting a new and effective way of cleaning mercury from water. Their new technology cleans contaminated water so that it is well within the safe limits for drinkability. 2018 (Photo by Mia Halleröd Palmgren) Posted for media use.

Björn Wickman and Cristian Tunsu are presenting a new and effective way of cleaning mercury from water. Their new technology cleans contaminated water so that it is well within the safe limits for drinkability. 2018 (Photo by Mia Halleröd Palmgren) Posted for media use.

How the New Technique Works

Over the last two years, Wickman and Cristian Tunsu, a researcher at the Department of Chemistry and Chemical Engineering at Chalmers, have studied an electrochemical process for cleaning mercury from water.

Their method involves a metal plate – an electrode – that binds specific heavy metals to it. The electrode is made of platinum; through an electrochemical process it draws the toxic mercury out of the water to form an alloy of the two – a mercury-platinum alloy.

In this way, the water is cleaned of the mercury contamination. The alloy formed by the two metals is very stable, so there is no risk of the mercury re-entering the water.

“An alloy of this type has been made before, but with a totally different purpose in mind. This is the first time the technique with electrochemical alloying has been used for decontamination purposes,” says Tunsu.

One strength of the new energy efficient cleaning technique is that the electrode has a very high capacity. Each platinum atom can bond with four mercury atoms. The mercury atoms do not only bond on the surface, but also penetrate deeper into the material, creating thick layers, allowing the electrode to be used for a long time. After use, the electrode can be recycled, and the mercury disposed of safely.

“Another great thing with our technique is that it is very selective. Even though there may be many different types of substance in the water, it just removes the mercury. Therefore, the electrode doesn’t waste capacity by unnecessarily taking away other substances from the water,” says Wickman.

A patent for the new method is being sought, and in order to commercialize the discovery, a new company, Atium, has been established.

The  innovation has already received a number of prizes and awards, both in Sweden and internationally. The research has also attracted a strong response from industry.

Right now, the researchers are working on a prototype that can be tested outside the lab under real-world conditions.

The technique could be used to reduce the amount of waste and increase the purity of waste and process water in the chemical and mining industries, and in metal production.

It could contribute to better environmental cleaning of places with contaminated land and water sources.

The new method can even be used to clean drinking water in badly affected environments because, due to its low energy use, it can be powered entirely by solar cells. As a result, it can be developed into a mobile and reusable water cleaning technology.

Read the article, “Effective removal of mercury from aqueous streams via electrochemical alloy formation on platinum” in the scientific journal “Nature Communications.

The Minamata Convention

The Minamata Convention on Mercury  is an international treaty designed to protect human health and the environment from human emissions and releases of mercury and mercury compounds.

Signed by 128 countries and ratified by 101 countries and the European Union, the Convention takes its name from the most severe mercury poisoning disaster in history, which came to light in Minamata, Japan, in May 1956, after sustained dumping of industrial waste waters into Minamata Bay, beginning in the 1930s.

Local villagers who ate fish and shellfish from the bay started suffering convulsions, psychosis, loss of consciousness and coma. Thousands of people were certified as having suffered from mercury poisoning, now known as Minamata disease.

Almost 150 countries, 94 of them Parties to the Minamata Convention on Mercury, met in Geneva in late November to strengthen their efforts to reduce and eliminate the adverse effects of mercury as a new UN report revealed that global mercury emissions into the atmosphere rose by around 20 percent between 2010 and 2015.

East and Southeast Asia, Sub-Saharan Africa and South America account for the greatest increases in mercury emissions between 2010 and 2015, according to the assessment.

For centuries, mercury has been used in measuring devices such as thermometers and blood pressure devices. The Minamata Convention stipulates the phase-out of manufacturing, as well as the import and export of these and other mercury-added products by 2020.

Over the next few decades, the Minamata Convention on Mercury is expected to reduce mercury pollution from the activities responsible for major releases of the toxic metal into the environment.

Featured Source Image:  A worker handles mercury with his bare hands in a small-scale gold mine in the province of Camarines Norte in the Bicol Region, Philippines. December 5, 2016 (Photo by International Labor Organization) Creative Commons license via Flickr


Maxtraining

World Puts First Limits on Mercury Emissions

Stainless steel balls at the Minamata Memorial Museau commemmorate the mercury exposure that killed thousands. (Photo by quirkyjazz)

Stainless steel balls at the Minamata Memorial Museau commemmorate the mercury exposure that killed thousands. (Photo by quirkyjazz)

By Sunny Lewis

GENEVA, Switzerland, August 17, 2017 (Maximpact.com News) – From now on, for the first time, emissions of the neurotoxic element mercury will be controlled by 74 countries List of ratifying countries as a global treaty took effect on Wednesday, protecting millions of children and infants from neurological and health damage.

The Minamata Convention on Mercury commits governments, including the United States, China and most European countries, to specific measures to limit mercury. The treaty bans new mercury mines, phases out existing mines, regulates artisanal and small-scale gold mining, and reduces emissions and mercury use in medical devices by 2020.

Exposure to mercury can harm the brain, heart, kidneys, lungs, and immune system, particularly in unborn children and babies.

There is no safe level of exposure to mercury nor are there any cures for mercury poisoning, which at high levels causes irreversible neurological and health damage.

Since the element is indestructible, the Convention also stipulates conditions for interim storage and disposal of mercury waste.

Up to 8,900 metric tonnes of mercury are emitted every year, according to the UN Environment Programme (UNEP). It can be released naturally through the weathering of rocks containing mercury, forest fires and volcanic eruptions, but human processes such as generating electricity in coal-burning power plants also emits mercury.

Artisanal small scale mining is responsible for up to 35 percent of global emission of mercury into the environment. Mining alone in 70 different countries exposes up to 15 million workers, including child laborers, to mercury poisoning.

Other human-made sources of mercury pollution include the production of chlorine and some plastics, waste incineration and use of mercury in laboratories, pharmaceuticals, preservatives, paints and jewelry.

UNEP head Erik Solheim said, “The Minamata Convention shows that our global work to protect our planet and its people can continue to bring nations together. We did it for the ozone layer and now we’re doing it for mercury, just as we need to do it for climate change – a cause that the Minamata Convention will also serve.”

“Together, we can clean up our act,” said Solheim.

The Convention takes its name from the most severe mercury poisoning disaster in history.

Between 1932 and 1968, the Chisso chemical factory in Minamata, Japan released large quantities of industrial wastewater into Minamata Bay that was contaminated with highly toxic methylmercury.

In 1956, local villagers suffered convulsions, psychosis, loss of consciousness, coma and death from eating the poisoned fish in Minamata Bay. Thousands of people were certified as having directly suffered from mercury poisoning.

Rimiko Yoshinaga was born in Myojin, Minamata City and grew up in a fishing family. At a memorial ceremony for Minamata disease victims on May 1, 2010, she told how she became ill and how her grandfather died from the disease.

“When this place was a sea,” she said, “we swam and gathered shells and seaweed. Both adults and children loved the sea so much. Meanwhile, fishes in Minamata Gulf started to swim unsteadily and shells opened their mouths, and the area was pervaded by a rancid smell. This was the beginning of a strange disease. In the end, cats, birds and also healthy people suffered a convulsion, groaned with pain, then died.”

“I remember that I went fishing with my grandfather on his fishing boat when I was 4 years old and Emiko, my cousin, had just turned 2 years old. My grandfather set up a little fire and baked the fishes to let us eat. I can imagine that we little girls ate happily thinking these fishes were fresh and tasted so good. No one could tell us they were contaminated fish.”

“The disease started to affect me. I often fell and got up again and again. Gradually I lost my strength and I could not walk at all,” she said.

“My mother carried me on her back to bring me to hospital many times. At the hospital, I got an injection on my back and it was very painful. After that, when I had to go to the hospital, I cried every time so my mother would not know what to do,” she said. “I felt uncomfortable to be called a person with ‘strange disease.'”

Yoshinaga entered elementary school late, because her father worried that she might be bullied by other students. She now works with disabled people.

“The national and prefectural government, not to mention Chisso, did not deal with the damages for so long,” said Yoshinaga. “They did not fulfill their responsibility and it remains tremendous challenge to restore.”

“I want them to listen to each citizen’s opinion so the governments and Chisso can both understand what people really need in this area. Minamata disease happened in such a small town where there are mountains, rivers, and sea where all creatures live,” she said. “Many precious things were taken away.”

There is no safe level of exposure to mercury nor are there cures for mercury poisoning, which at high levels causes irreversible neurological and health damage.

Unborn children and babies are the most vulnerable, along with populations who eat fish contaminated with mercury, those who use mercury at work, and people who live near a source of mercury pollution or in colder climates, where the toxic heavy metal tends to accumulate.

In addition, new research from the University of Geneva reveals that exposure to methylmercury is altering gene expression in algae. Mercury first found at very low amounts in water is concentrated along the entire food chain, from algae via zooplankton to small fish and on to the largest fish – the ones we eat.

By employing molecular biology tools, the scientists measured the way mercury affects the gene expression of algae, even when its concentration in water is very low, comparable to European environmental protection standards.

Working with an algae whose genome has been fully sequenced, they found that mercury disrupted the metabolism of this algae.

Lead researcher Professor Vera Slaveykova points out, “Of the 5,493 genes specifically dysregulated by methylmercury, we don’t yet know the function of 3,569 of them, even though this alga is the most widely studied of all.”

Another new study comparing mercury levels among young women in Asia and the Pacific revealed high traces of mercury in 96 percent of the women tested from Pacific communities with high fish consumption.

The study, “Mercury monitoring in women of childbearing age in the Asia and the Pacific Region,” jointly conducted by the interim secretariat of the Minamata Convention in Geneva, the Biodiversity Research Institute , and the global NGO International Positive Education Network (IPEN).

Researchers examined hair samples from women aged 18-44 from Cook Islands, Marshall Islands, Tuvalu, and Kiribati, and two landlocked Asian countries, Tajikistan and Nepal.

The study found 96 percent of the women sampled from the Pacific Islands contained elevated hair mercury levels.

In contrast to the Pacific Islands, samples from Tajikistan, where fish consumption is very low, had the least amount of mercury overall. In Nepal, elevated mercury levels were found in women with a low fish diet, but who worked making gold-plated religious idols using mercury.

“This study underscores the importance of biomonitoring mercury pollution,” said David Evers, PhD, executive director and chief scientist at BRI and co-author of the study. “Although the subjects in this study represent small selected populations, the information gained contributes to overall global information on mercury concerns.”

“Mercury contamination is ubiquitous in marine and freshwater systems around the world. Biological mercury hotspots are globally common and are related to a variety of human activities,” said Evers. “For these reasons, it is critical that we continue biomonitoring efforts to track potential impacts on local communities and on the environment in order to evaluate the effectiveness of the Minamata Convention.”

“Mercury has been recognized as a substance of global concern, with impacts on vulnerable populations,” said Jacob Duer, principal coordinator of the Minamata Convention’s Interim Secretariat. “Our results show why global action to prevent mercury releases through the Minamata Convention is so important.”

Regardless of U.S. ratification of the Minamata Convention in 2013 under President Barack Obama, the Trump administration’s Environmental Protection Agency (EPA) is reconsidering a Obama-era EPA rule that set the first national limits to protect public health from mercury emissions.

Environmental and health organizations, concerned citizens and industry representatives from across the United States came to Washington, DC, July 31 to speak at an EPA public hearing on its proposal to indefinitely delay the requirements of the 2015 Steam Electric Effluent Limitation Guidelines.

The reconsideration is being carried out in response to the coal-fired power industry’s concerns.

In his testimony, Waterkeeper Alliance President Robert F. Kennedy Jr. countered the utilities’ claims that making these investments would cause harm, comparing the harm to industry profits to the lasting developmental harm that mercury has on children.

Kennedy, an attorney specializing in environmental law, questioned the basis for EPA’s hearing, saying, “This hearing is illegal. I know the Clean Water Act and Administrative Procedure Act backwards and forwards. Nothing in there gives you authority to suspend a rule. There has already been a rulemaking that gave us the limits that EPA is now trying to destroy.”

EPA is expected to finalize its decision on delaying the requirements of the ELG rule later in August.

The Waterkeeper Alliance says it is prepared to challenge EPA in court if the agency continues to roll back protections.

The first meeting of the Parties to the Minamata Convention on Mercury will be held September 24 to 29 in Geneva.


Maximpact+WASTEFeatured Image: There is no safe level of exposure to mercury, and young children are most at risk. Japan, 2007 (Photo by Jim Epler)