Patterned-MOF-Functionalized Nanofiltration Membranes for Selective Removal of Selenium and Arsenic from Fracking Wastewater

用于选择性去除水力压裂废水中硒和砷的图案化 MOF 功能化纳滤膜

基本信息

批准号：
1941700
负责人：
Steven Weinman
金额：
$ 35.71万
依托单位：
University of Alabama Tuscaloosa
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：
2020-05-01 至 2025-04-30
项目状态：
未结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1941700&HistoricalAwards=false
关键词：
Patterned MOF Functionalized Nanofiltration Membranes

项目摘要

Hydraulic fracturing or "fracking" of rock layers to release the oil and gas trapped within produces a substantial amount of wastewater that is typically disposed of by pumping it back underground. This process has the unfortunate side-effect of increasing seismic activity in disposal areas. The ability to remove any hazardous components returned in the wastewater, so that it can be reused in the fracking process or for other purposes such as irrigation, would minimize the detrimental impact of fracking in local communities. Toxic heavy metals, such as selenium and arsenic, are among the hazardous materials found in fracking wastewater. This project will develop a new approach to remove selenium and arsenic from fracking wastewater using nanofiltration (NF) membranes. NF membranes are semi-permeable, meaning certain small molecules or ions (i.e., sodium chloride) pass through the membrane while other components are trapped behind the membrane. NF membranes are susceptible to oil-fouling when treating fracking wastewater, or in other words, oil contaminants remaining in the wastewater collects at the membrane surface until water and small molecules can no longer pass through. Therefore, this project will utilize surface patterns and anti-fouling metal organics frameworks (MOFs) to prevent membrane oil-fouling. MOFs are a class of highly porous crystalline materials formed from metal ions and organic linkers. MOFs are an attractive modifier in membrane synthesis since they can selectively capture dissolved molecules and ions from large volumes of fluid. The effectiveness of this separation arises from the affinity of the MOF for the molecule or ion, the extraordinarily high porosity of the material, and the ability to tune the sorbent properties of the material to the molecule of interest. Engineering surface patterns on the MOF is expected to create localized mixing such that foulant materials are less likely to stick to a membrane surface. The overall research effort aims to enable sustainable treatment schemes for fracking wastewater by removing toxic heavy metals. The proposed research will be carried out by graduate and undergraduate students, who will collaboratively develop research plans, mentor other students, and perform STEM outreach to local K-12 students from underrepresented groups. Additionally, water treatment and membrane design concepts will be incorporated into the research team’s classes to expose undergraduate and graduate students to current topics and challenges in water treatment.This project aims to mitigate oil-fouling and adsorption capacity reduction using surface patterns and anti-fouling metal-organic frameworks to maintain MOF selectivity for selenium and arsenic while incorporated in an NF membrane to treat fracking wastewater. The investigators hypothesize that surface micro-patterning and anti-fouling graphene oxide (GO)-decorated MOFs will mitigate oil-induced membrane fouling, thereby preventing capacity and selectivity loss of thin-film nanocomposite membranes in produced water service. The approach will examine three different sized micro-patterns and two types of GO-decorated MOFs to tailor anti-fouling ability, selectivity, and permeance. The project will yield fundamental understanding of how pattern size and synthesis procedure affect the MOF capacity, selectivity, and oil-fouling resistance. This project will generate new knowledge on whether GO-decorated MOFs, specifically GO-Cu- and GO-Fe-MOFs, improve anti-fouling performance over non-GO-decorated MOFs. Ultimately, the proposed research is expected to enable sustainable produced water treatment schemes through the removal of toxic heavy metals.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.

对岩层进行水力压裂或“压裂”以释放其中的石油和天然气会产生大量废水，这些废水通常通过将其泵回地下进行处理，该过程具有增加处置区域地震活动的不幸副作用。如果能够去除废水中返回的任何有害成分，以便将其重新用于水力压裂过程或用于灌溉等其他目的，则可以最大限度地减少水力压裂对当地社区造成的痛苦影响，例如有毒重金属。硒和砷是水力压裂废水中发现的有害物质，该项目将开发一种使用纳滤（NF）膜去除水力压裂废水中的硒和砷的新方法，纳滤膜是半渗透性的，这意味着某些小分子或离子（在处理压裂废水时，纳滤膜容易产生油垢，例如氯化钠）穿过膜，而其他成分则被截留在膜后面。或者换句话说，残留在废水中的油类污染物会聚集在膜表面，直到水和小分子不再通过。因此，该项目将利用表面图案和防污金属有机框架（MOF）来防止膜油污染。 MOF 是一类由金属离子和有机连接体形成的高度多孔的晶体材料，因为它们可以选择性地捕获大量流体中溶解的分子和离子，因此是膜合成中极具吸引力的改性剂。这种分离的原因在于 MOF 对分子或离子的亲和力、材料的极高孔隙率以及根据目标分子调整材料的吸附剂特性的能力。创建局部混合，使污染物不太可能粘附在膜表面。总体研究工作旨在通过去除有毒重金属来实现水力压裂废水的可持续处理方案。拟议的研究将由研究生和本科生进行。他们将合作制定研究计划，指导其他学生，并向来自弱势群体的当地 K-12 学生进行 STEM 推广。此外，水处理和膜设计概念将纳入研究团队的课程中，让本科生和研究生了解当前的主题。该项目旨在利用表面图案和防污金属有机框架来减轻油污和吸附能力降低，以保持 MOF 对硒和砷的选择性，同时将其纳入 NF 膜中进行处理研究人员发现，表面微图案以及防污氧化石墨烯（GO）装饰的 MOF 将减轻石油引起的膜污染，防止采出水服务中薄膜纳米复合膜的容量和选择性损失。三种不同尺寸的微图案和两种类型的 GO 修饰的 MOF 来定制防污能力、选择性和渗透性。该项目将产生对图案如何形成的基本了解。尺寸和合成程序会影响 MOF 的容量、选择性和抗油污性，该项目将产生关于 GO 修饰的 MOF（特别是 GO-Cu- 和 GO-Fe-MOF）是否比非 MOF 提高防污性能的新知识。最终，拟议的研究有望通过去除有毒重金属来实现可持续的采出水处理方案。该奖项反映了 NSF 的法定使命，并通过使用基金会的知识进行评估，被认为值得支持。优点和更广泛的影响审查标准。