Biologically-mediated Manganese Oxide Deposition and its Effects on Trace Metal Cycling in Aquatic Environments

环境地球化学和生物地球化学项目的这个奖项 支持环境中微量金属循环的研究。 伦纳德W. Lion，Michael L. Shelter，and William C.第一次世界大战 康奈尔大学土木与环境工程系。 这项研究得到了化学和地球分部的支持 科学和多学科活动的MPS办公室。 长 长期目标是开发一个精确的机械模型， 生物介导的表面涂层的形成及其随后的 天然和工程中过渡金属分布影响 环境. 该项目的重点是确定锰的作用 氧化物在控制过渡金属循环和发展 过程的定量模型。 特别是， 细菌过程和生物膜形成对锰氧化和 锰氧化物的金属结合将包括在模型中。 锰氧化和氧化锰沉积将在 在生物膜反应器系统中培养细菌，其中pH，温度， 溶解氧浓度、流体剪切和光强度可以 控制。 锰氧化物表面性质与铅的吸附 生物氧化样品的镉含量将与结果进行比较 用于非生物化学氧化还原过程。 其结果将是一个 综合计算模型预测锰氧化和 氧化锰痕量金属结合，包括细胞生长，生物膜 积累，锰氧化还原反应，和微量金属形态， 吸附作用 铁和锰氧化物颗粒对铅和镉的吸附作用， 被认为是运输这些有毒金属的重要手段， 自然环境 本研究旨在了解 氧化锰的吸附作用，包括作用 生物介导的锰氧化和循环，在运输 过程 结果也将与补救措施的发展有关 有毒金属的战略。

This award in the Environmental Geochemistry and Biogeochemistry program supports research on trace metal cycling in the environment by Drs. Leonard W. Lion, Michael L. Shuler, and William C. Ghiorse of the Department of Civil and Environmental Engineering, Cornell University. The research is supported by the Divisions of Chemistry and Earth Sciences and the MPS Office of Multidisciplinary Activities. The long term goal is to develop an accurate mechanistic model for predicting formation of biologically-mediated surface coatings and their subsequent influence on transition metal distribution in natural and engineered environments. This project focuses on identifying the role of manganese oxides in controlling transition metal cycling and on developing a quantitative model for the process. In particular, the influence of bacterial processes and biofilm formation on both manganese oxidation and metal binding by manganese oxides will be included in the model. Manganese oxidation and manganese oxide deposition will be measured in cultures of bacteria in a bioflim reactor system where pH, temperature, dissolved oxygen concentration, fluid shear and light intensity can be controlled. Manganese oxide surface properties and adsorption of lead and cadmium for biologically oxidized samples will be compared to results obtained for abiotic chemical redox processes. The result will be an integrated computational model to predict manganese oxidation and manganese oxide trace metal binding, including cellular growth, biofilm accumulation, manganese redox reations, and trace metal speciation and adsorption. Adsoprtion of lead and cadmium to iron and manganese oxide particles is thought to be an important means of transport of these toxic metals in the natural environment. This study is directed toward understanding the role of manganese oxide adsorption, including the role of biologically-mediated manganese oxidation and cycling, in the transport process. The results will also be relevant to development of remediation strategies for toxic metals.