Ferrate (Fe(VI))-Coated Sand Media for Simultaneous Oxidation of Organic Contaminants and Adsorption of Trace Metals in Water

高铁酸盐 (Fe(VI)) 包覆砂介质可同时氧化有机污染物并吸附水中的痕量金属

• 批准号: 2242483
• 负责人: Jessica Ray
• 金额: $ 35.96万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-10-01 至 2026-09-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2242483&HistoricalAwards=false
• 关键词: Ferrate; Fe; VI; Coated; Sand

Chemical oxidants such as chlorine and ozone are widely utilized as disinfectants and reactants to degrade harmful trace organic compounds in conventional water treatment processes. However, chlorination and ozonation can also lead to the formation of toxic byproducts during water treatment. Ferrate, Fe(VI) iron oxide, has emerged as a promising multifunctional reagent for water treatment due to its high redox potential, benign nature and demonstrated ability to serve as an oxidant, disinfectant, coagulant, and sorbent. However, ferrate rapidly decomposes in aqueous solutions at environmentally relevant pHs, which limits its reactivity and effectiveness as oxidant and functional reagent for water treatment. Previous studies have shown that silica gels can delay the decomposition of ferrate and catalyze the production of highly reactive ferrate iron oxyanion intermediate species. Building upon these promising findings, the Principal Investigator (PI) of this project proposes to test the hypothesis that sand, which is primarily composed of silica, can stabilize ferrate decomposition in aqueous solutions at environmentally relevant pH and enhance its reactivity and deployment as multifunctional reagent for water treatment. To test this hypothesis, the PI and project research team propose to 1) design, synthesize, and characterize ferrate-coated sand composite materials and 2) evaluate their performance as chemical oxidants and sorbents for non-selective water treatment. The successful completion of this project will benefit society through the generation of fundamental knowledge to advance the development and deployment of efficient and low-cost ferrate-based multifunctional materials for water treatment. Additional benefits to society will be achieved through student education and training including the mentoring of one graduate student at the University of Washington. Ferrate [Fe(VI)], an environmentally benign iron oxyanion, can oxidize organic pollutants in aqueous solutions while its reduced, non-toxic ferric [Fe(III)] phase can sorb heavy metals in water. However, at environmentally relevant pHs, ferrate rapidly decays thus limiting its treatment effectiveness. Previous studies have demonstrated that silica (SiO2) gels can slow down the charge transfer kinetics of ferrate to enhance its reactivity and efficiency as oxidant. However, these previous studies relied on the non-covalent coating and physical mixing of silica gels with ferrate. To harness the dual benefits of SiO2-stabilized ferrate for oxidation and sorption, the Principal Investigator (PI) and project research team will explore the covalent attachment of ferrate onto sand, a widely used silica-based water filtration media, with the goal of creating novel and low-cost multifunctional materials for water treatment. The specific objectives of the research are to 1) synthesize and characterize covalent composite ferrate-sand media; 2) probe the media stability in aqueous solutions and investigate iron (Fe) speciation during media reactions with organic and inorganic contaminants; 3) investigate and elucidate the interactions between the composite ferrate-sand media with relevant environmental compounds and species (e.g., dissolved organic matter and inorganic ions) that are known to impact redox reactions and sorption processes in aqueous solutions; and 4) investigate opportunities for in-situ regeneration and reuse of the composite ferrate-sand media. The successful completion of this project has the potential for transformative impact through the generation of new fundamental knowledge and materials to guide the design and deployment of more efficient and cost-effective multifunctional media for water treatment. To implement the education, training, and outreach goals of the project, the PI proposes to leverage existing programs at the University of Washington (UW) such as Engineering Days to engage 4th -8th students from the greater Seattle metropolitan area to perform lab demonstration experiments with the goal of exciting them about opportunities in STEM careers. In addition, the PI plans to lead an educational outreach activity in partnership with the “Hip Hop is Green” nonprofit organization to recruit and mentor high school students to gain research experience while working on ferrate treatment media in the PI’s lab at UW.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.

化学氧化物（例如氯和臭氧）被广泛用作消毒剂和反应物，以降解常规水处理过程中有害的有机有机化合物。但是，氯化和臭氧化也会导致水处理期间有毒副产品的形成。 Ferrate，Fe（VI）氧化铁，由于其高氧化还原潜力，良性性质以及作为氧化剂，毒性，毒剂，凝结剂和味道的能力而出现了用于水处理的多功能试剂。然而，在环境相关的pHS上，铁酸酯在水溶液中迅速分解，这限制了其作为水处理的氧化剂和功能试剂的反应性和有效性。先前的研究表明，硅胶可以延迟铁酸酯的分解，并催化高反应性铁酸铁氧中间物种的产生。在这些有希望的发现的基础上，该项目的主要研究者（PI）测试了主要由二氧化硅组成的沙子可以在水性溶液中稳定在环境相关的pH值中的铁酸酯分解并增强其反应性和部署为水处理的多功能试剂。为了检验这一假设，PI和项目研究团队的建议提案为1）设计，合成和表征富铁岩涂层的沙子复合材料，2）评估其作为非选择性水处理的化学氧化物和吸附剂的性能。该项目的成功完成将通过产生基本知识来使社会受益，从而促进高效和低成本的基于高成本的多功能材料进行水处理。通过学生的教育和培训将为社会带来其他好处，包括华盛顿大学一名研究生的心理。 Ferrate [Fe（VI）]是一种环境良性的铁氧，可以在水溶液中氧化有机污染物，而其降低，无毒的铁[Fe（iii）]相可以在水中进行重金属。但是，在与环境相关的pHS上，铁酸盐迅速衰减，从而限制了其治疗效果。先前的研究表明，二氧化硅（SIO2）凝胶可以减慢铁酸酯的电荷转移动力学，从而增强其作为氧化剂的反应性和效率。然而，这些先前的研究已减轻了二氧化硅凝胶与铁酸酯的非共价涂层和物理混合。为了利用SIO2稳定的铁ate对氧化和焊接的双重好处，首席研究员（PI）和项目研究团队将探索铁甲酸铁酸酯在Sand上的共价附件，这是一种基于二氧化硅的广泛水过滤介质，目的是创建新颖的和低成本的多功能材料，以进行水处理。研究的具体目标是1）合成并表征共价复合铁甲晶体培养基； 2）在水溶液中探测培养基的稳定性，并研究有机和无机污染物的培养基反应期间的铁（FE）规格； 3）研究并阐明了复合富甲酸酯培养基与相关的环境化合物和物种（例如，溶解的有机物和无机离子）之间的相互作用，这些化合物已知会影响水溶液中的氧化还原反应和焊料过程； 4）调查现场再生的机会和复合铁矿媒体的再利用。该项目的成功完成，通过产生新的基本知识和材料来指导设计和部署更有效，更具成本效益的多功能媒体进行水处理，从而有可能产生变革性的影响。为了实施该项目的教育，培训和外展目标，PI提案旨在利用华盛顿大学（UW）的现有计划，例如工程学日，以吸引来自大西雅图大都会地区的第4-8名学生，以执行实验室示范实验，以使他们激发他们在STEM职业生涯中激发他们的目标。此外，PI计划与“ Hip Hop Is Green”非营利组织合作领导教育外展活动，以招募和指导高中生在UW的PI实验室中从事Ferrate治疗媒体的工作，这一奖项反映了NSF的法定任务，反映了NSF的法定任务，并通过使用基础的智力效果和宽阔的评估来进行评估，并以评估为您提供了支持。