Collaborative Research: Electrodialysis/Reverse Osmosis - Development of an Improved Method to Concentrate Dissolved Organic Matter from Seawater

合作研究：电渗析/反渗透 - 开发浓缩海水中溶解有机物的改进方法

• 批准号: 0425624
• 负责人: Ellery Ingall
• 金额: $ 28.15万
• 依托单位: Georgia Tech Research Corporation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-08-01 至 2007-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0425624&HistoricalAwards=false
• 关键词: Collaborative; Research; Electrodialysis; Reverse; Osmosis

ABSTRACTOCE-0425624The large size and dynamics of the ocean dissolved organic matter (DOM) pool have made it an important focus of many studies of global elemental cycles. These studies are motivated by the direct and indirect influences of DOM cycling on processes such as global warming and marine productivity. Over the last three decades, numerous compositional studies of various size fractions and chemical extracts have significantly increased our understanding of the origin and cycling of marine DOM. A large fraction of marine DOM, however, still remains compositionally uncharacterized. A major obstacle in the study of marine DOM has been isolating from seawater sufficient quantities for analysis of this highly dilute and chemically complex material. In this project researchers at the Georgia Institute of Technology and Kansas State University will develop, test, and apply a process using reverse osmosis (RO) in combination with electrodialysis (ED) for the concentration and practical retrieval of significant quantities of essentially unaltered DOM from seawater. RO methods have been shown to recover a significant fraction (90%) of DOM from fresh waters with little physical or chemical alteration. Unfortunately, the extent to which a DOM sample can be concentrated by RO in saline waters is very limited because RO membranes co-concentrate inorganic salts with DOM. Salt accumulation during RO leads to solutions requiring very high pressures during processing to overcome osmotic forces and to formation of membrane-fouling inorganic precipitates. To achieve the same high DOM recoveries from saline waters that are achieved when RO is used to process fresh waters, an independent method for removal of inorganic salts is required. Electrodialysis, a well-established process for removal of inorganic salts from aqueous solutions, is such a method. Preliminary experiments by the co-investigators indicate that ED can significantly reduce salt concentrations in natural waters with little or no loss of DOM. Thus, the proposed process will use ED to reduce the salt concentrations, so that RO techniques can be used to recover DOM.A series of laboratory experiments using artificial and natural seawater solutions will be used to evaluate and optimize the coupled RO/ED process. During the final stage of this research, the combined technique will be applied to seawater samples. The PIs already have two laboratory-scale ED systems and a portable RO unit capable of processing large volumes of water (hundreds of liters), which represents a significant cost savings to NSF for this work.Broader Impacts: The expected result from this work is an enabling tool for environmental research that is far superior to the best current techniques (i.e., ultrafiltration) for recovery of marine DOM. Research involving the recovery of complex organic molecules in natural water sources (rivers, lakes, seawater) will be greatly facilitated by a field-deployable method for pre-concentration. In terms of broader educational impacts, this investigation will allow the PIs to train and mentor a diverse group of students and researchers, including several minorities and women.

ABSTRACTOCE-0425624海洋溶解有机物 (DOM) 池的大尺寸和动态使其成为许多全球元素循环研究的重要焦点。 这些研究的动机是 DOM 循环对全球变暖和海洋生产力等过程的直接和间接影响。 在过去的三十年中，对各种尺寸分数和化学提取物的大量成分研究显着增加了我们对海洋 DOM 的起源和循环的了解。 然而，很大一部分海洋 DOM 在成分上仍然没有特征。海洋 DOM 研究的一个主要障碍是从海水中分离出足够数量的物质来分析这种高度稀释且化学复杂的材料。在该项目中，佐治亚理工学院和堪萨斯州立大学的研究人员将开发、测试和应用一种将反渗透 (RO) 与电渗析 (ED) 相结合的工艺，用于从海水中浓缩和实际回收大量基本未改变的 DOM。 RO 方法已被证明可以从淡水中回收大部分 (90%) 的 DOM，几乎没有物理或化学变化。 不幸的是，由于 RO 膜与 DOM 共同浓缩无机盐，因此在盐水中通过 RO 浓缩 DOM 样品的程度非常有限。 反渗透过程中的盐积累导致溶液在处理过程中需要非常高的压力来克服渗透力并形成膜污染的无机沉淀物。为了从盐水中获得与使用反渗透处理淡水时相同的高 DOM 回收率，需要一种独立的无机盐去除方法。 电渗析是一种成熟的从水溶液中去除无机盐的方法。共同研究人员的初步实验表明，ED 可以显着降低天然水中的盐浓度，而 DOM 损失很少或没有。 因此，所提出的工艺将使用 ED 来降低盐浓度，以便 RO 技术可用于回收 DOM。将使用人造和天然海水溶液进行一系列实验室实验来评估和优化 RO/ED 耦合工艺。在这项研究的最后阶段，组合技术将应用于海水样本。 PI 已经拥有两个实验室规模的 ED 系统和一个能够处理大量水（数百升）的便携式 RO 装置，这对 NSF 的这项工作来说意味着显着的成本节省。 更广泛的影响：这项工作的预期结果是环境研究的一个有利工具，其远远优于目前回收海洋 DOM 的最佳技术（即超滤）。 可现场部署的预浓缩方法将极大地促进涉及天然水源（河流、湖泊、海水）中复杂有机分子回收的研究。 就更广泛的教育影响而言，这项调查将使 PI 能够培训和指导不同群体的学生和研究人员，包括一些少数族裔和女性。