Modification of PAN electrospun nanofiber membranes with g-C3N4 nanotubes/carbon dots to enhance MBR performance.

This study is dedicated to the enhancement of electrospun polyacrylonitrile (PAN) nanofiber membranes for their application in membrane bioreactor (MBR) processes. The improvement is achieved through the incorporation of graphitic carbon nitride nanotubes/carbon dots (g-C3N4 NT/CDs) and subsequent heat post-treatments at varying temperatures. Notably, the hot-pressing methodology effectively mitigates surface roughness and significantly reduces issues related to peeling during nanofiber experimentation. Our results demonstrate that the introduction of 0.5 wt% of g-C3N4 NT/CDs leads to a substantial enhancement in water flux. In particular, nanocomposite membranes subjected to hot-pressing at 90 °C for 10 min exhibited an impressive flux recovery ratio (FRR) of 70%. Furthermore, the heat-treated nanocomposite membranes exhibited remarkable antifouling properties and significantly reduced fouling rates when compared to their heat-treated bare counterparts. This study underscores the noteworthy potential of g-C3N4 NT/CDs-modified PAN nanofiber membranes to substantially elevate MBR performance, firmly positioning them as highly promising candidates for critical applications in the domains of water and wastewater treatment. However, it is imperative to underscore that the existing written material necessitates a comprehensive overhaul to align with the provided structural framework.

Development of Ti2AlN MAX phase/cellulose acetate nanocomposite membrane for removal of dye, protein and lead ions.

To our knowledge, this study was carried out because there is no other study using Ti2AlN MAX phase material as an inorganic additive to improve the performance of the cellulose acetate (CA) membrane. In this research, the effect of titanium aluminum nitride (Ti2AlN) MAX phase on the performance of CA polymeric membrane was investigated. In the first step, the Ti2AlN MAX phase was synthesized via the reactive sintering method and characterized. The Successful synthesis of the MAX phase with high purity in the hexagonal crystalline structure was confirmed with the XRD pattern. The prepared MAX phase was used as a hydrophilic inorganic additive to improve the performance of the CA membrane. An improvement in hydrophilicity of the CA membranes was observed by incorporating the MAX phase into the matrix of membranes. The nanocomposite membrane containing optimum content of MAX phase (0.75 wt%) showed a threefold increase in permeability during filtration of pure water and dye solutions. In addition, the optimum nanocomposite membrane exhibited an improved flux recovery ratio of 92.7 % with a high removal efficiency of 70.7 % for reactive black 5, 93.5 % for reactive red 120, and >98 % for bovine serum albumin. Finally, the rejection of different salts was investigated, and the optimum nanocomposite showed high rejection for lead ions (97 %) with moderate rejection for Na2SO4 (>55 %) and NaCl (>30 %). The results of this research demonstrated the high potential of MAX phase-based materials for improving polymeric membranes.