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.

海洋溶解有机质（DOM）池的巨大规模和动态变化使其成为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，许多组成的研究，各种尺寸的馏分和化学提取物显着增加了我们的理解的起源和循环的海洋DOM。 然而，海洋DOM的很大一部分在组成上仍然没有特征。研究海洋DOM的一个主要障碍是从海水中分离出足够的量来分析这种高度稀释和化学复杂的物质。在该项目中，格鲁吉亚理工学院和堪萨斯州立大学的研究人员将开发、测试和应用一种利用反渗透（RO）结合电渗析（艾德）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。反渗透方法已被证明可以从新鲜沃茨中回收相当大一部分（90%）的DOM，而几乎没有物理或化学变化。 不幸的是，DOM样品可以通过RO在盐水沃茨中浓缩的程度非常有限，因为RO膜共浓缩无机盐和DOM。 反渗透过程中的盐积累导致溶液在加工过程中需要非常高的压力来克服渗透力并形成膜污染无机沉淀物。为了从盐水沃茨中获得与使用RO处理淡水沃茨时相同的高DOM回收率，需要一种用于去除无机盐的独立方法。 电渗析，一种从水溶液中去除无机盐的成熟方法，就是这样一种方法。合作研究人员的初步实验表明，艾德可以显着降低天然沃茨中的盐浓度，而DOM的损失很少或没有。 因此，该工艺将利用艾德去除海水中的盐分，从而利用反渗透技术回收DOM。通过一系列人工海水和天然海水溶液的实验室实验，对反渗透/艾德耦合工艺进行了评价和优化。在本研究的最后阶段，将对海水样品应用该组合技术。 PI已经有两个实验室规模的艾德系统和一个便携式RO单元，能够处理大量的水（数百升），这代表了NSF这项工作的显着成本节省。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，远远上级目前最好的技术（即，超滤）用于回收海洋DOM。 可在实地部署的预浓缩方法将大大促进涉及从自然水源（河流、湖泊、海水）中回收复杂有机分子的研究。 就更广泛的教育影响而言，这项调查将使PI能够培训和指导各种学生和研究人员，包括一些少数民族和妇女。