Spiess Sabine, Kucera Jiri, Vaculovic Tomas, Birklbauer Ludwig, Habermaier Clemens, Conde Amaia Sasiain, Mandl Martin, Haberbauer Marianne
K1-MET GmbH, Linz, Austria.
Department of Biochemistry, Faculty of Science, Masaryk University, Brno, Czechia.
Front Microbiol. 2023 Aug 17;14:1238853. doi: 10.3389/fmicb.2023.1238853. eCollection 2023.
Metal recycling is essential for strengthening a circular economy. Microbial leaching (bioleaching) is an economical and environmentally friendly technology widely used to extract metals from insoluble ores or secondary resources such as dust, ashes, and slags. On the other hand, microbial electrolysis cells (MECs) would offer an energy-efficient application for recovering valuable metals from an aqueous solution. In this study, we investigated a MEC for Zn recovery from metal-laden bioleachate for the first time by applying a constant potential of -100 mV vs. Ag/AgCl (3 M NaCl) on a synthetic wastewater-treating bioanode. Zn was deposited onto the cathode surface with a recovery efficiency of 41 ± 13% and an energy consumption of 2.55 kWh kg. For comparison, Zn recovery from zinc sulfate solution resulted in a Zn recovery efficiency of 100 ± 0% and an energy consumption of 0.70 kWh kg. Furthermore, selective metal precipitation of the bioleachate was performed. Individual metals were almost completely precipitated from the bioleachate at pH 5 (Al), pH 7 (Zn and Fe), and pH 9 (Mg and Mn).
金属回收对于强化循环经济至关重要。微生物浸出（生物浸出）是一种经济且环保的技术，广泛用于从难溶矿石或诸如粉尘、灰烬和炉渣等二次资源中提取金属。另一方面，微生物电解池（MECs）可为从水溶液中回收有价金属提供一种节能应用。在本研究中，我们首次通过在处理合成废水的生物阳极上施加相对于Ag/AgCl（3M NaCl）为 -100 mV的恒定电位，研究了用于从含金属生物浸出液中回收锌的MEC。锌沉积在阴极表面，回收效率为41±13%，能耗为2.55 kWh/kg。作为对比，从硫酸锌溶液中回收锌的效率为100±0%，能耗为0.70 kWh/kg。此外，还对生物浸出液进行了选择性金属沉淀。在pH值为5（铝）、pH值为7（锌和铁）以及pH值为9（镁和锰）时，生物浸出液中的各种金属几乎完全沉淀。
