title: Proteins and protein-rich biomass as environmentally friendly adsorbents selective for precious metal ions.
abstract: Proteins exhibit specific interactions with various metal ions, which play important roles in a living cell. Here, we found that various proteins selectively adsorbed precious metal ions at a wide range of pH values. Studies on protein sequences and on synthesized peptides revealed that a histidine-containing sequence had specific interactions with precious metal ions (Au3+ and Pd2+). We then investigated a few types of protein-rich biomass as adsorbents for precious metal ions. In the presence of various transition metal ions, Au3+ and Pd2+ were also selectively adsorbed onto the biomass tested. The bound precious metal ions were recovered by aqua regia after charring the metal-bound biomass. Finally, we demonstrated the successful recovery of Au3+ and Pd2+ from a metal refining solution and a metal plating waste using the biomass. We propose an environmentally friendly recycling system for precious metal ions using protein-rich biomass.
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering and Center for Future Chemistry, Kyushu University, 744 Moto-oka, Fukuoka 819-0395, Japan. tmarutcm@mbox.nc.kyushu-u.ac.jp
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Maruyama
authors.forename: Hironari
authors.initials: H
authors.lastname: Matsushita
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Shimada
authors.forename: Ichiro
authors.initials: I
authors.lastname: Kamata
authors.forename: Misa
authors.initials: M
authors.lastname: Hanaki
authors.forename: Saori
authors.initials: S
authors.lastname: Sonokawa
authors.forename: Noriho
authors.initials: N
authors.lastname: Kamiya
authors.forename: Masahiro
authors.initials: M
authors.lastname: Goto
mesh_terms: D000327:Adsorption; D018533:Biomass; D003247:Conservation of Natural Resources / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste; D008669:Metallurgy; D008670:Metals / Q000737:chemistry*; D011506:Proteins / Q000737:chemistry*; D018505:Waste Management / Q000379:methods*
chemical_list: D007220:Industrial Waste; D008670:Metals; D011506:Proteins