Nitrate-selective Anion-Exchange Membranes: development and application in electrodialysis

Summary

Nitrogen fertilizers are essential in agriculture but pose environmental challenges, such as water pollution from nitrate runoff. Electrodialysis (ED) using ion-exchange membranes (IEMs) offers a solution to recover valuable resources like nitrate. However, separating nitrate from chloride, due to their similar properties, remains challenging. This thesis aims to develop anion-exchange membranes (AEMs) with enhanced nitrate selectivity, focusing on increasing membrane hydrophobicity to favour nitrate transport.
Experimental results demonstrate that polyvinylidene fluoride (PVDF)-based membranes show superior nitrate selectivity compared to commercial alternatives. Further research explores the impact of different polymers like polyvinyl chloride (PVC) and polyacrylonitrile (PAN), revealing that PVC-based membranes exhibit the best nitrate/chloride selectivity. This study offers insights into membrane design for more efficient nitrate recovery, contributing to a circular economy in fertilizer production. Future research directions are also discussed, emphasizing the development of even more selective AEMs for agricultural applications.