Excellence in Research: A Novel High Throughput Forward Osmosis Membrane for Produced Water Treatment

卓越的研究：用于采出水处理的新型高通量正向渗透膜

• 批准号: 1900787
• 负责人: Raghava Kommalapati
• 金额: $ 50万
• 依托单位: Prairie View A & M University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-08-01 至 2025-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1900787&HistoricalAwards=false
• 关键词: Excellence; Research; Novel; Throughput; Forward

Hydraulic fracturing operations for shale gas and oil production consume high volumes of fresh water eventually generating flowback water and produced water as byproducts. Much of this water is disposed of through deep-well injection which, if handled improperly, can cause environmental hazards. Ideally, produced water would instead be treated and discharged to the environment. Due to high levels of organic contaminants and various salts present in produced water, there is a lack of efficient and mature technologies for this application. Reverse osmosis is ineffective for treating produced water because the osmotic pressure caused by the high salinity repels the hydraulic pressure used in reverse osmosis. Forward osmosis is an emerging technology that is suitable for treating produced water since it is a naturally osmotic process. Forward osmosis membranes have shown promising performance for separating organic pollutants and salt from some wastewater and for treating produced water at high salinity. However, to apply forward osmosis technologies to produced water treatment at the industrial scale, there are technical challenges that must be addressed, including: (1) relatively low flux of commercially available forward osmosis membranes, (2) membrane fouling caused by deposition of organic matter during forward osmosis, and (3) ammonia loss from the water feeding side of the membrane when ammonia-carbon dioxide is used as draw solute in the forward osmosis process. The project will develop a unique dual-skinned forward osmosis membrane designed to overcome these challenges. Computational modeling will be applied to describe the mechanisms by which flux is improved and fouling is mitigated. Research and education will be integrated through educational activities and training of undergraduate and graduate students. These activities will prepare students to become community-engaged scholars as well as future policymakers through a service-learning pedagogy.The goal of this research is to make it possible to efficiently treat shale oil and gas produced water at the industrial level. Toward this goal, the project will investigate a novel high throughput forward osmosis membrane design that is optimized for treating high-salinity produced water. The forward osmosis membrane will consist of an intermediate nanofibrous support layer and double ultrathin skins on both sides of the support layer. The support layer will be a porous nanofiber textile containing polyetherimide and graphene oxide. To reduce membrane fouling and to repel ammonia loss from the feeding produced water side, the membrane skins will be coated with zwitterionic polymers, which are highly hydrophilic. Membrane synthesis, characterization, and performance evaluation is integrated with molecular dynamics simulation to fabricate and optimize a membrane for produced water treatment using the forward osmosis process. The performance and stability of the developed membrane for treating produced water will be examined over the long-term, and the environmental and economic impacts of the new produced water treatment process will be evaluated through a life cycle assessment.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.

页岩气和页岩油的水力压裂作业消耗大量淡水，最终产生的副产品是返排水和采出水。这些水大部分是通过深井注入处理的，如果处理不当，可能会造成环境危害。理想情况下，采出水将被处理并排放到环境中。由于采出水中存在高浓度的有机污染物和各种盐类，因此缺乏有效和成熟的技术。反渗透处理采出水是无效的，因为高盐度引起的渗透压排斥了反渗透所使用的水压。正渗透是一种新兴的技术，由于它是一种自然渗透过程，因此适用于处理采出水。正向渗透膜在分离废水中的有机污染物和盐分以及处理高盐度采出水方面表现出了良好的性能。然而，要将正向渗透技术应用于工业规模的采出水处理，必须解决的技术挑战包括：(1)市售正向渗透膜的通量相对较低；(2)正向渗透过程中有机物沉积造成的膜污染；(3)正向渗透过程中氨-二氧化碳作为吸取溶质时膜给水侧的氨损失。该项目将开发一种独特的双层正向渗透膜，旨在克服这些挑战。计算模型将用于描述提高通量和减轻污染的机制。研究和教育将通过教育活动和本科生和研究生的培训相结合。这些活动将通过服务学习教学法使学生成为参与社区的学者以及未来的政策制定者。本研究的目的是使页岩油气采出水在工业水平上的有效处理成为可能。为了实现这一目标，该项目将研究一种新型的高通量正向渗透膜设计，该膜设计经过优化，可用于处理高盐度采出水。正向渗透膜由中间的纳米纤维支撑层和支撑层两侧的双层超薄表皮组成。支撑层将是含有聚醚酰亚胺和氧化石墨烯的多孔纳米纤维纺织品。为了减少膜污染和防止进料产水侧的氨损失，膜表面将被涂覆一层两性离子聚合物，这是一种高度亲水的聚合物。膜的合成、表征和性能评估与分子动力学模拟相结合，利用正向渗透工艺制造和优化用于采出水处理的膜。将对所开发的用于处理采出水的膜的性能和稳定性进行长期测试，并通过生命周期评估来评估新采出水处理工艺的环境和经济影响。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。