? Gold binding by native and chemically modified hop biomasses ?

LÓPEZ, M.L., GARDEA-TORRESDEY, J.L., PERALTA-VIDEA, J.R., DE LA ROSA, G., ARMENDARIZ, V., JOSE-YACAMAN M AND TROIANI H.E.

BIOINORGANIC CHEMISTRY AND APPLICATIONS

HINDAWI PUBLISHING CORPORATION

Año: 2005 vol. 3 p. 29 - 41

1565-3633

Heavy metals from mining, smelting operations and other industrial processing facilities pollutewastewaters worldwide. Extraction of metals from industrial effluents has been widely studied due to theeconomic advantages and the relative ease of technical implementation. Consequently, the search for newand improved methodologies for the recovery of gold has increased. In this particular research, the use ofcone hops biomass (Humulus lupulus) was investigated as a new option for gold recovery. The resultsshowed that the gold binding to native hops biomass was pH dependent from pH 2 to pH 6, with a maximumpercentage binding at pH 3. Time dependency studies demonstrated that Au(III) binding to native andmodified cone hops biomasses was found to be time independent at pH 2 while at pH 5, it was timedependent. Capacity experiments demonstrated that at pH 2, esterified hops biomass bound 33.4 mg Au/g ofbiomass, while native and hydrolyzed hops biomasses bound 28.2 and 12.0 mg Au/g of biomass,respectively. However, at pH 5 the binding capacities were 38.9, 37.8 and 11.4 mg of Au per gram of native,esterified and hydrolyzed hops biomasses, respectively.