Synthesis of Amino-Functionalized Zeolite Frameworks for the Development of Advanced Nanofiltration Membranes: Desalination and Micropollutant Removal

The demand of water reclamation is rising globally with an increasing demand of clean water for various anthropogenic activities. The treated wastewater coming from domestic and industrial sources has many micropollutants that are harmful to human life and aquatic ecosystems[1]. Such micropollutants are becoming a part of marine life[2]. Removal of micropollutants alongside desalination is an emerging challenge of the current era. Therefore, the current project is aimed at fabrication of advanced zeolite decorated nanofiltration membranes that will reject both mono/di-valent ions and micropollutants to an appreciable extent[3, 4]. An advantage of crosslinking zeolites in membrane active layer lies in their salient features such as porosity, stability, and tunability of functional groups over the surface[5]. Hence, the current proposed project will be executed by synthesizing micro and meso porous zeolite called MCM-41. The zeolite material will be either in-situ functionalized during zeolite synthesis or through a post-synthesis strategy. Mostly in reported literature related to membrane fabrication, MCM-41 has been modified using post-synthetic strategies. To the best of our knowledge, these material synthesis strategies alongside comparison of their effectiveness will be the first of its kind. The as-synthesized material will be thoroughly characterized to establish the structure and chemistry of zeolites using Field emission scanning electron microscopy (FE-SEM), Fourier transform infra-red spectroscopy (FTIR), X-ray diffraction analysis (XRD) or other relevant advanced analytical techniques as and when applicable. The membranes will be fabricated by casting polysulfone by wet inversion method[6]. The interfacial polymerization will be done over the polysulfone surface using 2% diamine solution containing appropriate dispersion of the weight percent of amine terminated zeolite. The amine termination will allow the zeolite to have a chemical bond during polyamide formation and to avoid agglomeration. Later, in the presence of crosslinker, a polyamide active layer decorated with zeolite will be formed. The membranes will be characterized using atomic force microscopy (AFM), contact angle (CA), X-ray photoelectron spectroscopy (XPS), FE-SEM, FTIR and others as needed. The flux of the membrane at various pressure will be tested. Rejection experiments will be done for mono and/or divalent ions and micropollutants. The proposed project can produce international publication and/or patent.