Proteins and protein-rich biomass as environmentally friendly adsorbents selective for precious metal ions.
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.
Maruyama
Tatsuo
T
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
Matsushita
Hironari
H
Shimada
Yukiko
Y
Kamata
Ichiro
I
Hanaki
Misa
M
Sonokawa
Saori
S
Kamiya
Noriho
N
Goto
Masahiro
M
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*
D007220:Industrial Waste; D008670:Metals; D011506:Proteins