The same process that causes crusts to form inside teapots could help clear nickel contamination from seawater, according to a new study from the South Pacific island of New Caledonia.
        Nickel mining is New Caledonia’s main industry, and the tiny island is one of the largest producers of the metal in the world. But the combination of large quarries and heavy rainfall means that large amounts of nickel, as well as lead and other metals, are ending up in the waters around the island. Nickel pollution can be detrimental to human health as its concentration in fish and shellfish increases as they move up the food chain.
       Marc Jeannin, an environmental engineer at the University of La Rochelle in France, and his colleagues at the University of New Caledonia in Noumea wondered if they could use the cathodic protection process, a technique used to control corrosion of marine metal structures, to pull some nickel out of the water. .
        When a weak electrical current is applied to metals in sea water, it causes calcium carbonate and magnesium hydroxide to precipitate out of the water and lime deposits form on the surface of the metal. This process has never been studied in the presence of metallic contaminants such as nickel, and the researchers wondered if some of the nickel ions could precipitate.
        The team threw a galvanized steel wire into a bucket of artificial seawater mixed with NiCl2 salt and ran a mild electric current through it for seven days. At the end of this short period, they found that as much as 24 percent of the nickel originally present was trapped in scale deposits.
        Jeannine says this can be a cheap and easy way to get rid of the nickel. “We can’t eliminate all pollution, but this could be a way to limit it,” he said.
        The results were somewhat unexpected, since the elimination of pollution was not among the goals of the original research program. Jeannin’s main research focuses on developing ways to combat coastal erosion—he explores how limestone deposits buried in a wire mesh on the ocean floor can act as natural cement, helping to stabilize sediments under dams or on sandy beaches.
        Jeannin started a project in New Caledonia to determine if the mesh could trap enough metal contaminants to help study the history of nickel contamination at the site. “But when we discovered that we could capture large amounts of nickel, we started thinking about possible industrial applications,” he recalls.
        Christine Orians, an environmental chemist at the University of British Columbia in Vancouver, says the method can remove not only nickel, but a host of other metals as well. “Co-precipitation is not very selective,” she told Chemistry World. “I don’t know if it would be effective in removing enough toxic metals without removing potentially useful metals like iron.”
        However, Jeannine is not concerned that the system, if deployed on a large scale, will deprive the oceans of vital minerals. Only 3% of calcium and 0.4% of magnesium have been removed from the water during the experiments, and he says the iron content in the ocean is high enough not to affect it much.
        In particular, Jeannin suggested that such a system could be deployed in places with high nickel runoff, such as the port of Nouméa, to reduce the amount ending up in the sea. It requires minimal supervision and can be connected to renewable energy sources such as solar panels. Nickel and other contaminants trapped in scale can be recovered and recycled.
       Jeannin said he and his colleagues are working with companies in France and New Caledonia to develop a pilot project to help determine whether the system can be rolled out commercially.
       The inexpensive molecule provides similar performance to existing expensive metal catalysts, but faces serious problems regarding its stability.
       $210 million donation from Moderna entrepreneur and investor Tim Springer to support ongoing research
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