UNS: Engineered Nanomaterial Impact on Long-Term Stability of MSW Landfill and Leachate Treatment Pond Geomembrane Liners

1510869随着含有纳米材料的工程产品的使用寿命即将结束，它们很可能会被安置在城市固体废物填埋场。在南卡罗来纳大学首席研究员(PI)实验室进行的工作表明，碳纳米管的流动性，作为工程纳米材料的例子，在含有“成熟”渗滤液(主要由腐植酸组成)的废物环境中可能具有重要意义。这项研究的主要目标是进行实验和进行分子模拟，以了解城市垃圾填埋场中工程纳米材料-土工膜相互作用的影响。工程纳米材料的产量持续增加：因此，含有工程纳米材料的产品/废物将不可避免地进入垃圾填埋场。遗憾的是，目前还没有程序或研究来评估目前设计和运行的垃圾填埋场和渗滤液处理/储存池是否能够充分管理/容纳这些材料。尤其重要的是理解工程纳米材料如何与衬里中存在的土工合成材料相互作用。这项工作将阐明工程纳米材料对高密度聚乙烯土工膜的影响，以及重要的是，它们可能如何影响土工膜的耐久性/使用寿命。这项研究具有变革性，因为它是第一次探索工程纳米材料-高密度聚乙烯衬里相互作用的研究。结果将提供必要的信息，以评估目前的固体废物管理程序是否足以安全地管理/控制这类废物。研究成果将通过演示文稿和出版物广泛传播。该项目的指导假设是，工程纳米材料将通过增加抗氧化剂的释放/消耗来影响土工膜的长期稳定性。工程纳米材料对土工膜的影响性质取决于材料的应用(例如，垃圾填埋场底部衬垫或渗滤液储存池)和环境条件(例如，氧气的存在)。这项工作的具体目标是：(1)阐明选定的工程纳米材料如何影响高密度聚乙烯衬里的聚合物氧化、抗氧剂扩散和随后的力学行为变化；(2)了解纳米工程材料表面化学如何影响聚合物氧化和抗氧剂扩散；以及(3)进行分子水平模拟，以计算氧化反应的吸附/分配系数、量化扩散系数和计算反应动力学，并开发一个过程模型来量化工程纳米材料对高密度聚乙烯衬里抗氧剂消耗的影响。在进行这项研究的同时，国际和平研究所致力于促进教学、培训和学习。更广泛的影响计划由三个部分组成：(1)K-12外联；(2)为工程学中代表性不足的人群提供本科研究经验；以及(3)博士生指导。预计可以通过这些计划的活动接触到大量潜在的未来工程师和科学家。

1510869Berge As engineered nanomaterial-containing products reach the end of their useful life, they will likely reside in municipal solid waste landfills. Work conducted in the principal investigator's (PI's) laboratory at the University of South Carolina suggests that the mobility of carbon nanotubes, examples of engineered nanomaterials, may be significant in waste environments containing "mature" leachate (consisting primarily of humic acid). The main goal of this research is to conduct experiments and perform molecular modeling simulations to understand the implications associated with engineered nanomaterial-geomembrane interactions in municipal solid waste landfills.Engineered nanomaterial production continues to increase: therefore it is inevitable that engineered nanomaterial-containing products/wastes will end up in landfills. Unfortunately, there are no processes or research to evaluate whether currently designed and operating landfills and leachate treatment/storage ponds can adequately manage/contain these materials. Of particular importance is the understanding of how engineered nanomaterials may interact with the geosynthetics present in the liners. This work will elucidate the impact of engineered nanomaterials on high-density polyethylene geomembranes and importantly, how they may influence geomembrane durability/service lives. This research is transformative in that it is the first study in which engineered nanomaterial-high-density polyethylene liner interactions will be explored. Results will provide necessary information to assess whether current solid waste management processes are adequate to safely manage/contain such wastes. The research results will be widely disseminated via presentations and publications. This project is guided by the hypothesis that engineered nanomaterials will influence long-term stability of geomembranes by increasing antioxidant release/depletion. The nature of engineered nanomaterial influences on geomembranes are dependent on material application (e.g., landfill bottom liner or leachate storage pond) and environmental conditions (e.g., oxygen presence). The specific objectives of this work are: (1) Elucidate how selected engineered nanomaterials influence polymer oxidation, antioxidant diffusion, and subsequent changes in mechanical behavior of high-density polyethylene liners; (2) Understand how engineered nanomaterial surface chemistry influences polymer oxidation and antioxidant diffusion; and, (3) Perform molecular level simulations to calculate adsorption/partitioning coefficients, quantify diffusion coefficients, and calculate reaction kinetics for oxidation reactions, and develop a process model to quantify the effects of engineered nanomaterials on antioxidant depletion in high-density polyethylene liners. The PI is committed to promoting teaching, training, and learning while conducting this research. The broader impacts plan is comprised of three components: (1) K-12 outreach; (2) undergraduate research experiences for underrepresented populations in engineering; and, (3) doctoral student mentoring. It is anticipated that a large population of potential future engineers and scientists can be reached through these planned activities.