铁还原菌作用下施氏矿物的还原溶解和相转化

施氏矿物的产生及转化对于酸性矿山排水（acid mine drainage，AMD）中元素迁移转化具有重要影响，文章以安徽省马鞍山市某酸性矿山坑湖沉积物中分离得到的铁还原菌 Clostridium sp. Z5480 菌株为代表，开展生物还原实验，研究其对施氏矿物的还原溶解及其相转化行为。结果表明：在厌氧条件下，Clostridium sp. Z5480 能够促进施氏矿物向磁铁矿和针铁矿的转化；随着施氏矿物表面吸附态 Fe（Ⅱ）的形成，促进了次生铁矿物的生成；pH 值的变化、氧化还原电位（oxidation-reduction potential，ORP）降低及 Fe（Ⅱ）质量浓度的增加均证实了该过程的发生。该研究结果为铁还原菌在施氏矿物上的还原过程提供了理论依据，有助于认识 AMD 污染环境中铁硫元素的地球化学循环及相关污染物的迁移转化行为。

The generation and transformation of schwertmannite have a significant impact on the migration and transformation of elements in acid mine drainage (AMD). This study took Clostridium sp. Z5480, an iron-reducing bacterium isolated from the sediment of a pit lake in an acid mine in Ma'anshan City, Anhui Province, as a representative to conduct a biological reduction experiment, aiming to investigate its reductive dissolution and phase transformation behavior of schwertmannite. The experimental results indicated that under anaerobic conditions, Clostridium sp. Z5480 could promote the transformation of schwertmannite into magnetite and goethite. Additionally, the formation of surface adsorbed Fe(II) on schwertmannite facilitated the generation of secondary iron minerals. The changes in pH value, the decrease in oxidation-reduction potential (ORP), and the increase in Fe(II) concentration all confirmed the occurrence of this process. This study provides a theoretical basis for understanding the reduction process of iron-reducing bacteria on schwertmannite and is helpful for recognizing the geochemical cycle of iron and sulfur elements and the migration and transformation behavior of related pollutants in AMD-contaminated environments.