Ordinary newspaper can be used to recover precious metals from industrial wastewater, say researchers in Japan.
Katsutoshi Inoue, and co-workers from Saga University, formed an active gel by treating newspaper with p-amino benzoic acid - a readily available compound used in sunscreen. Inoue shows that when water is passed through a column packed with this modified paper gold, palladium and platinum are filtered out in preference to other metals.
The modified newspaper is able to filter out gold, palladium and platinum in preference to other metals
Recovering valuable precious metals from industrial effluent is highly desirable, but not easy. Current methods suffer from incomplete metal removal, are expensive and have toxic waste products. Inoue's method overcomes these problems, whilst also providing a use for old newspapers.
Jarek Drelich an expert in materials science at Michigan Technological University, Houghton, US, agrees saying that the route 'opens the prospect of mass producing waste biomass-based sorbents that could benefit not only the hydrometallurgical industry but also the paper recycling industry'.
Inoue showed that a column packed with the gel could be used repeatedly, a good sign for industrial applications. Future challenges for the Japanese workers include separation and purification of the recovered metals.