Abstract Bioleaching ability of two acidophiles, viz. Acidithiobacillus ferrooxidans, a gammaproteobacteria, and Acidiphilium acidophilum, an alphaproteobacteria in pure and mixed strains was comparatively evaluated for the recovery of metals from waste printed circuit boards (WPCBs) of computer at pulp density in the range of 7.5−15 g/L. Results indicated a variation in metal leachability, showing improved bioleaching by the mixed strain. Mixed strain demonstrated the highest bioleaching of 96% Cu, 94.5% Zn, 75% Ni, and 74.5% Pb from the pulverized particles ranging from 0.075–1 mm size with a pulp density of 7.5 g/L at 18 days with asymptoticity from 12 days onward. Further, the corresponding maximum bioleaching efficiency by the mixed culture for precious and rare earth metals achieved was 46% Ag, 38% Au, and 31% Sc, 27% each of Ce and La, and 24% Nd. Improved bioleaching by the mixed culture may be due to the synergistic growth of the bacterial strains producing a collective effect leading to efficient metal solubilization. Higher production of exopolymeric substances (EPS) by the mixed culture demonstrated their remarkable role in metal bioleaching. A yield of greater than 99% of base metals by fractional chemical precipitation of bioleachate served as a concluding step in metal recovery.

中文翻译：

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使用氧化亚铁硫杆菌和嗜酸嗜酸杆菌的纯菌株和混合菌株从废印刷电路板中生物冶金回收金属

摘要 两种嗜酸菌的生物浸出能力，即。氧化亚铁酸硫杆菌（一种γ变形菌）和嗜酸嗜酸菌（一种纯菌株和混合菌株中的α变形菌）在纸浆密度范围为 7.5-15 g/L 的情况下，对从废旧印刷电路板 (WPCB) 中回收金属的计算机进行了比较评估。结果表明金属浸出性的变化，表明混合菌株的生物浸出得到改善。混合菌株表现出最高的生物浸出率：96% Cu、94.5% Zn、75% Ni 和 74.5% Pb 从 0.075-1 mm 大小的粉碎颗粒中浸出，18 天时纸浆密度为 7.5 g/L，渐近性为 12几天后。此外，贵金属和稀土金属的混合培养相应的最大生物浸出效率为 46% Ag、38% Au 和 31% Sc，Ce 和 La 各 27%，和 24% Nd。通过混合培养改进的生物浸出可能是由于细菌菌株的协同生长产生了导致有效金属溶解的集体效应。混合培养产生的外聚合物质 (EPS) 的更高产量证明了它们在金属生物浸出中的显着作用。通过生物浸出液的分级化学沉淀，贱金属的产率超过 99%，这是金属回收的最后一步。