Development of sustainable and low cost nitrate selective anion exchange polymers from agricultural wastes

利用农业废物开发可持续且低成本的硝酸盐选择性阴离子交换聚合物

• 批准号: 2007049
• 负责人: Elizabeth Butler
• 金额: $ 33万
• 依托单位: University of Oklahoma Norman Campus
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-08-01 至 2024-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2007049&HistoricalAwards=false
• 关键词: Development; sustainable; low; cost; nitrate

Groundwater is the most important source of freshwater in the world. In the United States, groundwater provides nearly half of the drinking water supply. Nitrate contamination of groundwater is a significant global problem. Consumption of nitrate-contaminated water can cause cancers, neural defects, and thyroid disease. Consequently, the US EPA has set the maximum contaminant level (MCL) for nitrate in drinking water at 10 mg/L nitrate-nitrogen. At present, anion exchange resins are the best commercially available technology for removing nitrate from contaminated groundwater. However, this technology is often too expensive for many public and private systems that rely on groundwater. The goal of this project is to address the need for lower cost materials and technologies for the removal of nitrate from drinking groundwater sources. To achieve this goal, the investigator will synthesize, characterize, and optimize the performance of a new family of low-cost nitrate-selective anion exchange polymers using cellulose extracted from agricultural wastes as building blocks. The successful completion of this project will benefit society through the development of more cost effective and sustainable technologies for nitrate removal to achieve US EPA regulations. Further benefits to society will be achieved through student education and training via the integration of the project findings into undergraduate and graduate course modules on adsorption, groundwater quality, and life cycle assessment. Groundwater contamination by nitrate has become a major problem worldwide. Commercial and selective anion exchange resins used to extract nitrate from contaminated groundwater are expensive. Moreover, their synthesis requires the use of hazardous chemicals including petroleum-derived polymers such as styrene and divinylbenzene. The goal of this research is to develop new and lower cost nitrate-selective anion exchange polymers using cellulose from agricultural wastes. To achieve this goal, the PI will conduct an experimental program structured around four tasks. Task I will investigate the extraction of cellulose from corn cobs and wheat stalks using sodium periodate, a low-cost inorganic salt as oxidant. In Task II, the oxidized functional groups of the extracted cellulose will be converted to amine linkages to enable subsequent polymer crosslinking and functionalization for selective nitrate removal. Functional groups that will be evaluated include quaternary ammonium compounds and tertiary amines with structures and properties optimized for nitrate selectivity. In Task III, batch and column experiments will be conducted to evaluate the nitrate selectivity of the new anion exchange polymers in water matrices containing high concentration of competing sulfate divalent anions. In Task IV, life cycle analysis (LCA) will be carried to assess the environmental impact and sustainability of the new nitrate-selective anion exchange polymers. The successful completion of this research has potential for transformative impact through the development of lower cost and more sustainable anion exchange polymers for the selective removal of nitrate from contaminated drinking groundwater sources.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.

地下水是世界上最重要的淡水资源。在美国，地下水提供了近一半的饮用水供应。地下水硝酸盐污染是一个重大的全球性问题。饮用被硝酸盐污染的水会导致癌症、神经缺陷和甲状腺疾病。因此，美国环保署将饮用水中硝酸盐的最大污染物水平（MCL）设定为10毫克/升的硝酸盐氮。目前，阴离子交换树脂是去除受污染地下水中硝酸盐的最佳商业技术。然而，对于许多依赖地下水的公共和私人系统来说，这项技术往往过于昂贵。该项目的目标是解决从饮用地下水中去除硝酸盐的低成本材料和技术的需求。为了实现这一目标，研究者将合成、表征和优化一个新的低成本硝酸盐选择性阴离子交换聚合物家族，该聚合物使用从农业废物中提取的纤维素作为构建块。该项目的成功完成将通过开发更具成本效益和可持续的硝酸盐去除技术来造福社会，以达到美国环保署的规定。通过将项目成果纳入有关吸附、地下水质量和生命周期评估的本科和研究生课程模块，对学生进行教育和培训，将进一步造福社会。地下水硝酸盐污染已成为世界性的重大问题。用于从污染地下水中提取硝酸盐的商业和选择性阴离子交换树脂价格昂贵。此外，它们的合成需要使用危险化学品，包括苯乙烯和二乙烯基苯等石油衍生聚合物。本研究的目的是利用农业废弃物中的纤维素开发新的低成本的硝酸盐选择性阴离子交换聚合物。为了实现这一目标，PI将围绕四个任务进行一个实验计划。任务一将研究使用低成本无机盐高碘酸钠作为氧化剂从玉米芯和小麦秸秆中提取纤维素。在任务II中，提取的纤维素的氧化官能团将转化为胺键，从而使随后的聚合物交联和功能化能够选择性地去除硝酸盐。将评估的官能团包括结构和性能为硝酸盐选择性优化的季铵化合物和叔胺。在任务III中，将进行批和柱实验，以评估新型阴离子交换聚合物在含有高浓度竞争硫酸盐二价阴离子的水基质中的硝酸盐选择性。在任务四中，将进行生命周期分析（LCA），以评估新的硝酸盐选择性阴离子交换聚合物的环境影响和可持续性。这项研究的成功完成有可能通过开发更低成本和更可持续的阴离子交换聚合物来选择性去除受污染的饮用地下水中的硝酸盐，从而产生变革性的影响。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。