Study describes new method to remove nickel from contaminated seawater

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The same deposit that builds up in many tea kettles or water pipes in areas where calcium-rich water is the norm might be just the (cheap) ticket to rid contaminated seawater of toxic metals. This is according to a study by a research group led by Charlotte Carré of the University of New Caledonia in the French Pacific territory of New Caledonia and published today in Springer’s journal Environmental Chemistry Letters. The researchers dipped electrodes made from galvanized steel into contaminated seawater and ran a weak current through it. Within seven days, up to 24 percent of the nickel it initially contained was trapped in a calcareous build-up of limestone.

The same deposit that builds up in many tea kettles or water pipes in areas where calcium-rich water is the norm might be just the (cheap) ticket to rid contaminated seawater of toxic metals. This is according to a study by a research group led by Charlotte Carré of the University of New Caledonia in the French Pacific territory of New Caledonia and published today in Springer’s journal Environmental Chemistry Letters. The researchers dipped electrodes made from galvanized steel into contaminated seawater and ran a weak current through it. Within seven days, up to 24 percent of the nickel it initially contained was trapped in a calcareous build-up of limestone.

Nickel mining activities in New Caledonia itself are causing the subsequent pollution of local coastal waters. The remediation of metals brings considerable challenges since these elements, given their chemical properties, can never be degraded but only stabilized. Therefore Carré’s research team set out to find an efficient, rapid and inexpensive method by which to remove such toxic metals from the contaminated waters.

The research team dipped cheap and commercially available galvanized steel electrodes into nickel-enriched seawater, and allowed a fairly weak electric current to run through it for seven days.

According to Carré, the method is relatively inexpensive and easy to use and requires no regular monitoring. “Metal contaminants are attracted and trapped inside a calcareous deposit as long as the structure is connected to a power source,” she explains. 

Read more at Springer

Photo credit: George Louis via Wikimedia Commons