论文部分内容阅读
本文实验研究了希瓦氏奥奈达菌株(Shewanella oneidensis MR-1,以下简称MR-1)在pH为中性的厌氧条件下还原针铁矿的过程,探讨了MR-1菌异化还原针铁矿的动力学特征。采用邻菲罗啉分光光度法检测了反应前后溶液中铁含量的变化,利用扫描电子显微镜、粉晶X射线衍射和激光拉曼光谱分析了针铁矿及其还原产物的形貌特征和物相组成。结果表明,针铁矿在厌氧条件下可被MR-1还原,生成磁铁矿、菱铁矿等次生矿物。本文认为针铁矿的微生物异化还原过程以直接接触机制为主,同时存在间接还原机制;溶液中的Fe2+与CO32-、SO42-等沉淀生成菱铁矿等次生产物,同时部分Fe2+、Fe3+离子可吸附于矿物表面,甚至能引起矿物相的转化,两者共同构成了针铁矿的次生分解路径。
In this paper, the process of reducing goethite in Shepardnella oneidensis MR-1 (hereinafter referred to as MR-1) under anaerobic conditions at pH neutrality was studied in this paper. The dissimilatory reduction needle of MR-1 Kinetic characteristics of iron ore. The phenanthroline spectrophotometry was used to detect the change of iron content in the solution before and after the reaction. The morphology and phase composition of goethite and its reduction products were analyzed by scanning electron microscopy, powder X-ray diffraction and laser Raman spectroscopy . The results show that goethite can be reduced by MR-1 under anaerobic conditions to produce secondary minerals such as magnetite and siderite. In this paper, it is considered that the direct microbial contact mechanism of goethite is dominated by direct contact mechanism, and indirect reduction mechanism exists at the same time. Fe2 + and CO32- and SO42- precipitate in the solution generate secondary products such as siderite. At the same time, some Fe2 +, Fe3 + It can adsorb on the mineral surface and even cause the transformation of the mineral phase, which together constitute the secondary decomposition path of goethite.