Mata Y N, Torres E, Blázquez M L, Ballester A, González F, Muñoz J A
Departamento de Ciencia de los Materiales e Ingeniería Metalúrgica, Facultad de Ciencias Químicas, Universidad Complutense de Madrid s/n, Madrid 28040, Spain.
J Hazard Mater. 2009 Jul 30;166(2-3):612-8. doi: 10.1016/j.jhazmat.2008.11.064. Epub 2008 Nov 27.
In this paper, the bioreduction of Au(III) to Au(0) using biomass of the brown alga Fucus vesiculosus was investigated. The recovery and reduction process took place in two stages with an optimum pH range of 4-9 with a maximum uptake obtained at pH 7. In the first stage, an induction period previous to gold reduction, the variation of pH, redox potential and gold concentration in solution was practically negligible and no color change was observed. In the second stage, the gold reduction was followed by a sharp decrease of gold concentration, pH and redox potential of solution and a color change from yellow to reddish purple. Hydroxyl groups present in the algal polysaccharides were involved in the gold bioreduction. Metallic gold was detected as microprecipitates on the biomass surface and in colloidal form as nanoparticles in the solution. Bioreduction with F. vesiculosus could be an alternative and environmentally friendly process that can be used for recovering gold from dilute hydrometallurgical solutions and leachates of electronic scraps, and for the synthesis of gold nanoparticles of different size and shape.
本文研究了利用褐藻墨角藻的生物质将Au(III)生物还原为Au(0)的过程。回收和还原过程分两个阶段进行，最佳pH范围为4 - 9，在pH 7时获得最大吸附量。在第一阶段，即金还原之前的诱导期，溶液中pH、氧化还原电位和金浓度的变化几乎可以忽略不计，且未观察到颜色变化。在第二阶段，金还原后溶液中的金浓度、pH和氧化还原电位急剧下降，颜色从黄色变为红紫色。藻类多糖中存在的羟基参与了金的生物还原过程。在生物质表面检测到金属金以微沉淀形式存在，在溶液中以纳米颗粒的胶体形式存在。利用墨角藻进行生物还原可能是一种替代的、环境友好的方法，可用于从稀湿法冶金溶液和电子废料浸出液中回收金，以及合成不同尺寸和形状的金纳米颗粒。
