CAREER: Design of surface modified membranes for recovery of key fertilizer macronutrients from wastewater

随着世界人口的增长，对肥料的营养成分（氮（N），磷（P）和钾（K））的需求已经很高，预计还会增加。生产这些营养素的传统技术是能源密集型的，并且与大量的碳足迹有关。另一方面，这些营养物质大量存在于废水中，事实上，它们释放到湖泊和溪流中会导致环境问题，如藻类过度繁殖和富营养化，这需要数十亿美元的补救措施。膜工艺可以在解决这两个挑战方面发挥重要作用，回收关键的肥料成分，防止它们释放到环境中，同时减少对传统能源密集型工艺的依赖。在这项工作中，研究人员旨在确定和分析聚电解质改性膜中的关键分离机制，以从废水中回收两种关键的常量营养素-氮（铵离子，NH 4+）和钾（K+）。教育活动将通过夏季研讨会为低收入的第一代学生提供指导研究的机会，这些学生传统上在STEM高等教育中代表性不足。此外，该项目还旨在通过引入新的体验式学习举措来改善工程专业学生的招聘和保留。研究人员的目的是确定和分析关键的分离机制，在改性膜，使选择性回收肥料宏量营养素从废水中的中性pH值条件下，目标是指导先进的膜开发。PI的研究将分析聚电解质改性膜中的尺寸排阻，基于电荷的运输和基于水合的分离的作用，以促进有机/营养物的分配和可调比例的营养物的回收。PI旨在开发一个基本框架，将膜形态特性与不同的分离机制（如尺寸排阻、基于电荷的传输和基于水合作用的离子分离）联系起来，这些机制必须协同作用才能实现理想的有机物/营养物分离。该奖项反映了NSF的法定使命，并被认为值得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来支持。

The demand for the constituent nutrients of fertilizer (Nitrogen(N), Phosphorus (P) and Potassium(K)), which is already high, is expected to grow as the world population grows. The traditional technologies to produce these nutrients are energy intensive and are associated with large carbon footprints. On the other hand, these nutrients are abundantly present in wastewater and, in fact, their release into lakes and streams leads to environmental problems like excessive algal blooms and eutrophication, which requires billions of dollars for remediation. Membrane processes could play an important role in solving both of these challenges by recovering key fertilizer components and preventing their release into the environment while reducing the reliance on traditional energy-intensive processes. In this work, the investigator aims to identify and analyze the critical separation mechanisms in polyelectrolyte-modified membranes for the recovery of two key macronutrients - nitrogen (as ammonium ion, NH4+) and potassium (K+) from wastewater. The educational activities will provide mentored research opportunities to low- income, first-generation students, who are traditionally underrepresented in STEM higher education via summer workshops. Additionally, the project also aims to improve the recruitment and retention of students in engineering via introduction of a new experiential learning initiative. The investigator aims to identify and analyze the critical separation mechanisms in polyelectrolyte modified membranes that enable selective recovery of fertilizer macronutrients from wastewater under neutral pH conditions, with the goal to guide advanced membrane development. The PI’s research will analyze the role of size exclusion, charge based transport, and hydration-based separation in polyelectrolyte-modified membranes to facilitate organic/nutrient partitioning and recovery of nutrients in tunable proportions. The PI aims to develop a fundamental framework that relates membrane morphological properties to different separation mechanisms like size-exclusion, charge-based transport and hydration-based ion separation which must be synergized to achieve desirable organic/nutrient separation.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.