Impact of Interactions between Metal Oxides to Redox Reactivity of Iron and Manganese Oxides

金属氧化物之间的相互作用对铁和锰氧化物氧化还原反应性的影响

• 批准号: 1762691
• 负责人: Huichun Zhang
• 金额: $ 0.6万
• 依托单位: Case Western Reserve University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-08-21 至 2018-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1762691&HistoricalAwards=false
• 关键词: Impact; Interactions; between; Metal; Oxides

1236517ZhangUnderstanding the fate of emerging contaminants in the environment is critical for assessing their potential risks to ecological systems. Yet, quantitative estimates of contaminant fate in complex environmental systems cannot be accurately obtained through experimentation and modeling with simple model systems. For this reason, this project will investigate complex model systems containing binary oxide mixtures to resemble soil-water environments: iron (Fe) or manganese (Mn) oxides as the redox active oxides and aluminum, silicon or other iron oxides as the second oxides. The main objective is to determine how the presence of a second metal oxide affects the redox activity of Fe/Mn oxides. Specifically, two model systems will be examined for their redox reactivity with respect to eight organic contaminants: an oxidizing environment containing either manganese dioxide or goethite as the dominant oxidant and a reducing environment containing soluble ferrous ions in the presence of goethite as the dominant reductant. Experimental and modeling work will be carried out to study the reaction kinetics of the target contaminants in the above systems. Potential particle interactions will be evaluated based on surface complexation, surface precipitation, heteroaggregation, and competitive adsorption. This study is the first to examine how the interactions between two different types of metal oxides affect the redox activity of iron and manganese oxides. This research will generate knowledge that is critical for predicting the fate of emerging contaminants in redox active soil-water environments. The intellectual merit of this project is based on: 1) a fundamental understanding of the nature of interactions within binary oxide mixtures and how these interactions are affected by solution chemistry including pH, oxide composition, and ionic strength; 2) a mechanistic understanding of how a second metal oxide affects the redox behavior of Fe/Mn oxides under oxic and anoxic conditions; and 3) quantitative modeling of the relative contribution of each type of interaction between metal oxides to the overall inhibitory effect of a second metal oxide on the redox activity of Fe/Mn oxides.This study will create a new body of knowledge available to aquatic chemists, environmental engineers, geochemists and microbiologists working with metal oxides in terms of either the activity of soil-water environments or contaminant removal. By developing complex model systems, results of this project can enable a more accurate risk analysis which could eventually be used by public health and environmental agencies for contaminant regulation and environmental clean-up. This project will also contribute to training, mentoring and overall development of graduate, undergraduate and high school students. Other planned outreach activities include participation of underrepresented minority and female students (particularly from the Society of Women Engineers), one-week summer workshops for female high school students, broad dissemination to over 30 industrial partners at the annual industrial advisory board meetings for the NSF Water and Environmental Technology (WET) Center, integration into the environmental curriculum at the Temple University, and presentation at Temple seminars that serve 1000+ Temple members and 3000+ working professionals from the great Philadelphia area.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

1236517zhangundercanders在环境中新兴污染物的命运对于评估其生态系统的潜在风险至关重要。 然而，在复杂环境系统中污染物命运的定量估计无法通过实验和使用简单模型系统进行建模来准确地获得。 因此，该项目将研究含有二元氧化物混合物的复杂模型系统，使其类似于土壤水环境：铁（Fe）或锰（MN）氧化物作为氧化还原活性氧化物和铝，硅或其他氧化物作为第二个氧化物。 主要目标是确定第二种金属氧化物的存在如何影响Fe/Mn氧化物的氧化还原活性。 具体而言，将检查两个模型系统，以相对于八种有机污染物的氧化还原反应性：一个含有二氧化锰或谷石的氧化环境，作为主要的氧化剂和含有可溶性铁矿离子的还原环境。 实验和建模工作将进行研究，以研究上述系统中靶污染物的反应动力学。 将根据表面络合，表面降水，杂聚集和竞争吸附来评估潜在的颗粒相互作用。 这项研究是第一个研究两种不同类型的金属氧化物之间的相互作用如何影响铁和锰氧化物的氧化还原活性。 这项研究将产生知识，这对于预测氧化还原活性土壤环境中新兴污染物的命运至关重要。 该项目的智力优点基于：1）对二元氧化物混合物中相互作用性质的基本理解，以及这些相互作用如何受到溶液化学影响，包括pH，氧化物组成和离子强度； 2）对第二种金属氧化物如何影响Fe/Mn氧化物在氧和缺氧条件下的氧化还原行为的理解； 3）金属氧化物之间每种相互作用对第二种金属氧化物对Fe/Mn氧化物氧化还原活性的总体抑制作用的相对贡献的定量建模。这项研究将创建一个可用于水生化学家的新知识体系，环境工程师，地球化学主义者和微生物学家就土壤水环境的活性或去除污染物而与金属氧化物一起工作。 通过开发复杂的模型系统，该项目的结果可以实现更准确的风险分析，最终可以被公共卫生和环境机构用于污染物法规和环境清理。 该项目还将有助于研究生，本科和高中生的培训，指导和整体发展。 其他计划的外展活动包括参加人数不足的少数群体和女学生（尤其是女性工程师协会），女性高中生的为期一周的夏季研讨会，在年度NSF的年度工业顾问委员会会议上进行了广泛的传播。水与环境技术（湿）中心，坦普尔大学的环境课程集成到寺庙研讨会上，为1000多个寺庙成员和3000多名来自大费城地区的职业专业人员提供服务。这奖反映了NSF的法定任务，并且一直是认为值得通过基金会的智力优点和更广泛影响的评论标准来评估值得支持。