Evaluational Equipment for Biological Weathering.

摘要：金属吸附和生物矿化在很大程度上反映了水圈系统中溶解金属的有效性。这种携带金属的细菌对金属从水圈到沉积物的转移有着深远的影响。在各种温度条件下，微生物将在金属沉积过程中发挥重要作用。在生命周期中，微生物将溶解在水中的金属浓缩到细胞壁和细胞内的位置，并在早期成岩过程中强烈结合金属。观察到了一个序列，在这个序列中，集中在细胞壁的无定形阳离子逐渐转化为碳酸盐、硅酸盐、锰铁氧化物和粘土矿物的微晶聚集体。生物沉淀氧化物和氢氧化物在水中有毒金属分散环境中对重金属如铜、铅、锌、镉、锶和铀具有清除作用。通过电子显微镜和能量色散X射线光谱仪在实验室模拟中跟踪了细菌细胞的生物矿化过程。对几种细菌去除溶液中重金属的能力进行了检测。扫描电子显微镜、透射电子显微镜、X射线荧光光谱和X射线衍射仪结果表明，老化几天后，大部分金属以晶态析出物的形式聚集在细胞表面。

Abstract : Metal sorption and biomineralization largely reflect the availability of dissolved metals in hydrosphere systems. The metal-loaded bacteria has profound implications for the transfer of metals from the hydrosphere to the sediments. Microorganisms will have playd an important role in metal deposition under various temperature conditions. The microorganisms concentrate aqueous dissolved metals onto cell walls and at intracellular sites, during the life cycle, and strongly bind metals during early diagenesis. A sequence is observed in which amorphous cations concentrated at cell walls are progressively transformed to microcrystalline aggregates of carbonate, silicate, Mn-Fe oxides, and clay minerals. The bioprecipitated oxides and oxyhydroxides act as scavengers for heavy metals such as Cu, Pb, Zn, Cd, Sr, and U,in the aqueous toxic-metal dispersion environment. The biomineralization of bacterial cells has been followed in a laboratory simulation by electron microscopy and energy-dispersive X-ray spectroscopy. Several kinds of bacteria were examined for the ability to remove heavy metals from solution. SEM-EDX,TEM,XRF and XRD results indicated that most of metals accumulated at the cell surface as crystalline precipitates after several days of aging.