Mopping up heavy metals

Chinese chemists have shown that biofunctional magnetic nanoparticles based on mould can 'adsorb' toxic heavy metals on to their surface.¹ The nanoparticles are being developed as a remediation material for metals such as the toxic hexavalent chromium. 

Industrial waste streams are increasingly contaminated with metal ions. These pollutants are non-degradable and persist in Nature. Significant among them is chromium(VI), the chromate ion. Chromium(VI) compounds are increasingly used in the chemical industry of the developing world for chrome plating, dye production, battery manufacture and other applications, despite the regulation of their use elsewhere. Hexavalent chromium is more toxic than its trivalent form and is a known carcinogen by inhalation. Ingestion of Cr(VI) causes problems in the digestive tract and lungs, stomach pain and nausea.