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

对化肥的组成营养素(氮(N)、磷(P)和钾(K))的需求已经很高，预计将随着世界人口的增长而增长。生产这些营养素的传统技术是能源密集型的，而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资金。膜工艺可通过回收关键肥料成分并防止其排放到环境中，在解决这两个挑战方面发挥重要作用，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回收废水中两种关键常量营养素-氮(如铵离子，NH4+)和钾(K+)的关键分离机理。教育活动将通过暑期研讨会为低收入的第一代学生提供指导研究的机会，这些学生在STEM高等教育中的代表性传统上较低。此外，该项目还旨在通过引入一项新的体验式学习计划来改善工程专业学生的招聘和留住。研究人员的目标是确定和分析聚电解质改性膜中的关键分离机理，使其能够在中性pH条件下选择性地从废水中回收肥料常量营养素，以期指导先进膜的开发。PI的研究将分析聚电解质改性膜中的尺寸排斥、基于电荷的传输和基于水合的分离的作用，以促进有机/养分分配和以可调比例回收养分。PI旨在开发一个基本框架，将膜的形态特性与不同的分离机制联系起来，如尺寸排斥、基于电荷的传输和基于水合的离子分离，这些机制必须协同作用才能实现理想的有机/营养分离。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

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.