TY - JOUR
T1 - Reduction and accumulation of gold(III) by Medicago sativa alfalfa biomass
T2 - X-ray absorption spectroscopy, pH, and temperature dependence
AU - Gardea-Torresdey, J. L.
AU - Tiemann, K. J.
AU - Gamez, G.
AU - Dokken, K.
AU - Cano-Aguilera, Irene
AU - Furenlid, Lars R.
AU - Renner, Mark W.
PY - 2000/10/15
Y1 - 2000/10/15
N2 - We report herein the use of Medicago sativa alfalfa shoot biomass for the removal of gold from aqueous solutions. The accumulation process involves the reduction of Au(Ill) to colloidal Au(O) and is shown to increase at elevated temperatures and at lower pH. X-ray absorption spectroscopy (XAS) was used to determine that gold(Ill) was reduced to form gold(0) colloids, which varied in size depending on the pH of the initial solution. The gold cluster radius was 6.2±1 angstroms at pH 5 and 9.0±1 angstroms at pH 2. Our findings indicate that essentially another layer of gold atoms was deposited onto the colloid surface at pH 2. Possible mechanisms of bioreduction and accumulation are discussed.
AB - We report herein the use of Medicago sativa alfalfa shoot biomass for the removal of gold from aqueous solutions. The accumulation process involves the reduction of Au(Ill) to colloidal Au(O) and is shown to increase at elevated temperatures and at lower pH. X-ray absorption spectroscopy (XAS) was used to determine that gold(Ill) was reduced to form gold(0) colloids, which varied in size depending on the pH of the initial solution. The gold cluster radius was 6.2±1 angstroms at pH 5 and 9.0±1 angstroms at pH 2. Our findings indicate that essentially another layer of gold atoms was deposited onto the colloid surface at pH 2. Possible mechanisms of bioreduction and accumulation are discussed.
UR - http://www.scopus.com/inward/record.url?scp=0034667712&partnerID=8YFLogxK
U2 - 10.1021/es991325m
DO - 10.1021/es991325m
M3 - Article
AN - SCOPUS:0034667712
VL - 34
SP - 4392
EP - 4396
JO - Environmental Science and Technology
JF - Environmental Science and Technology
SN - 0013-936X
IS - 20
ER -