A Joint Research Effort between UMCP and UNAM: "Environmental Risk of Arsenic: Geochemical Processes and Speciation"

9613706条洪流了解环境中重金属的来源和汇，对于开发防止这些元素污染的技术至关重要。这项拟议的研究解决了砷在最终进入地下水或地表水之前与土壤和沉积物的物理和化学相互作用。这一专题在所有拉丁美洲国家特别是墨西哥具有特别重要的意义。地下水和地表水的砷污染会导致癌症等人类健康问题，在复杂的地球化学反应决定其命运的矿区尤为严重。为了帮助了解各种矿物在自然条件下的反应如何相互作用，以及场地地球化学如何影响As金属和类金属的迁移，该研究将研究As的形态和吸附作为土壤矿物组成、pH、Eh和溶解的有机和无机离子的存在的函数。主要目标是量化不同进程对AS移动性的相对重要性。具体目标包括：开发有意义的实验室淋溶测试，以评估砷和富砷尾矿的不稳定程度；开发分析和提取技术，以确定土壤中砷的形态；量化铁和锰氧化物在砷保留中的重要性；量化控制溶解的因素。了解砷的地球化学可以带来更好的污染预防手段，特别是来自采矿来源的污染。这项拟议的工作是马里兰大学园区学院(UMCP)和墨西哥自治大学(UNAM)之间正在进行的合作协议的一部分，该协议旨在建立一个环境工程项目，该项目将为学生/研究人员的访问提供便利，开发基础设施，以促进“三明治”学位(来自马里兰大学园区的学生在墨西哥开展实地工作，来自墨西哥的学生参加墨西哥大学的课程)，就本国感兴趣的主题培训墨西哥学生，并发现和建立两所大学之间新的共同感兴趣的领域。拟议的研究将使用在不同pH值和氧化还原条件下添加不同水平砷的替代污染土壤，以及真实的富砷尾矿，并将包括实验室和实地工作的混合物。将设计良好的受控实验室研究来阐明机制。在墨西哥进行的实地研究将从动力学和热力学两个角度阐明不同机制的相对重要性。该提案所采取的办法和所获得的知识不仅将有利于采矿社区周围的环境，而且还将惠及砷浓度往往较高的广大地热和农业区。所获得的知识将为建立污染控制技术提供基础。

9613706 Torrents Understanding the sources and sinks of heavy metals in the environment is critical to developing technologies to prevent pollution from these elements. The proposed research addresses the physical and chemical interactions of arsenic with soils and sediments before it ultimately finds its way into ground or surface water. This topic is of particular importance in all Latin American countries and especially Mexico. Arsenic pollution of groundwater and surface waters leads to human health problems such as cancer, and is particularly problematic in mining areas where complex geochemistries determine its fate. To help understand how the reactions of various minerals interact under natural conditions and how the site geochemistry influences the migration of As metals and metalloids, the research will study As speciation and sorption as a function of soil mineral composition, pH, Eh, and the presence of dissolved organic and inorganic ions. The major objective is to quantify the relative importance of the different processes on As mobility. Specific objectives include: developing meaningful laboratory leaching tests to assess how labile As and As-rich-tailings are; developing analytical and extraction techniques to determine As- speciation in soils; quantifying the importance of Fe and Mn oxides in As retention; quantifying factors controlling As dissolution. An understanding of As geochemistry can lead to better means of pollution prevention, especially from mining sources. The proposed work is part of an ongoing collaboration agreement between University of Maryland College Park (UMCP) and Universidad Autonoma de Mexico (UNAM) to build a program in Environmental Engineering which will facilitate the visits by students/researchers, develop an infrastructure to facilitate "sandwich' degrees (students from UMCP to conduct field work in Mexico and students from Mexico to participate in courses at UMCP), train Mexican students in topics of interest to their own country, and identify and establish new areas of common interest between the two universities. The proposed research will use both surrogate contaminated soils spiked with different levels of As under different pH and redox conditions, and real As-rich tailings and will include a mixture of laboratory and field work. Well controlled laboratory studies will be designed to elucidate mechanisms. The field studies, conducted in Mexico, will elucidate the relative importance of the different mechanisms from both a kinetic and a thermodynamic approach. The approach taken in this proposal and the knowledge gained will not only benefit the environment surrounding mining communities but also extensive geothermal and agricultural areas where arsenic concentrations are often high. Knowledge gained will provide a basis upon which pollution control technologies may be established.***