China has something of a reputation as a copier rather than a developer of new technologies, so it is encouraging to read that researchers at Hunan Normal University (one wonders if they also have an Un-normal University?) have pioneered a technique to remove chrome as a polutant from waste waters. None would argue that chrome is a highly useful metal, mainly of course as an alloying element in stainless steels where it’s environmental problems are low but it’s use in chrome plating, dye production, battery manufacture and so on often results in the developing world in large scale pollution in the form of leaching into water sources of chromate or hexavalent chrome. The research team is developing a low cost method of absorbing the chrome onto magnetic nano-particle beads and then recycling the metal. The contaminated particles are removed from the water via an external magnetic field where the metal is extracted before the particles are returned for the waste water to be used again.
The technique would be of use anywhere. Heavy metals are present in waste water and could reduce the need for alternative and more expensive environmental safeguards associated with use of heavy metals in manufacturing.