CAREER: Reactivity of Green Rust Compounds in Natural and Engineered Systems

9983719谢勒据估计，美国有300,000至400,000个地点受到各种有毒化学物质的高度污染。事实证明，传统的清理做法相对无效，成本高得令人望而却步，促使人们转向依赖自然过程的就地清理技术，这些过程很少或根本不需要人为干预，以减少土壤或地下水中污染物的质量、毒性或移动性。最近，铁矿物表面在这些系统中的潜在作用已经被认识到。具体地说，绿色铁锈(一组还原的铁化合物)已被证明可以降解各种优先污染物，并可能有助于自然和工程系统中污染物的降解。这一研究项目的目标是通过评估绿色锈病的潜在作用来改进现场修复技术的评估和性能。这将通过：(1)量化绿色锈菌与一系列环境污染物的反应性，(2)研究绿色锈菌转化污染物的机制，以及(3)确定土壤和地下水中绿色锈菌的流行程度。将使用间接(间歇和柱式反应器)和直接(电化学和光谱)方法相结合的方法来评估绿色锈病的流行和反应性。从这项工作中得出的动力学数据将提供绿色锈菌减少这些污染物的第一组速率系数。将对一些地下环境进行采样和分析，并对柱状实验中形成的氧化物进行表征。从这些调查中得出的见解将为预测污染物的自然衰减和评估绿色锈病在铁基修复技术性能中的重要性提供更好的基础。这项研究的多面性为本科生介绍环境工程领域提供了良好的环境。将启动一项涉及环境工程研究的本科生女性参与的试点计划，以改善工程领域女性的留住、招聘和晋升。通过将女本科生置于积极的研究环境中，并为女研究生和教职员工提供榜样，PI希望在目前她们所在的领域留住和招聘聪明、有智力能力的女性。***

9983719 Scherer It is estimated that there are between 300,000 and 400,000 sites in the USA highly contaminated with a wide variety of toxic chemicals. Conventional cleanup practices have proved relatively ineffective and prohibitively costly, spurring a paradigm shift towards in situ cleanup technologies that rely on natural processes that act with little or no human intervention to reduce the mass, toxicity or mobility of contaminants in soil or groundwater. Recently the potential role of iron mineral surfaces in these systems has been recognized. Specifically, green rusts (a group of reduced iron compounds) has been shown to degrade a wide variety of priority pollutants and may be contributing to the degradation of pollutants in natural and engineered systems. The goal of this research project is to improve the assessment and performance of in situ remediation technologies by evaluating the potential role of green rusts. This will be accomplished by: (1) quantifying the reactivity of green rusts with a series of environmental contaminants, (2) investigating the mechanism by which green rusts transform contaminants and (3) determining the prevalence of green rusts in soil and groundwater. The prevalence and reactivity of green rusts will be evaluated using a combination of indirect (batch and column reactors) and direct (electrochemical and spectroscopic) methods. The kinetic data derived from this work will provide the first set of rate coefficients for reduction of these contaminants by green rusts. A number of subsurface environments will be sampled and analyzed and the oxides that form in column experiments will be characterized. The insights derived from these investigations will provide an improved basis for predicting the natural attenuation of contaminants and assessing the significance of green rusts in the performance of iron-based remediation technologies.The multifaceted nature of this research provides an excellent environment to introduce undergraduate students to the field of Environmental Engineering. A pilot program involving Undergraduate Women in Environmental Engineering Research will be launched to improve the retention, recruitment and advancement of women in engineering. By exposing women undergraduates to an active research environment and providing female graduate student and faculty role models, the PI hopes to retain and recruit bright, intellectually capable women in a field in which they are currently under-represented. ***