 | Membrane-based RO desalination technology, like any other desalination technology, is not free from some serious challenges. The two major problems related to RO applications in desalination are membrane biofouling and Chlorine attack, which negatively affect the performance efficiency in RO industries. To promote the large-scale utilization of RO membrane technologies, it is crucial to overcome the challenges faced by current RO membranes. The present research was designed to investigate novel PVA RO membranes with various fillers and combinations and their effectiveness as active RO separation layers with improved biofouling and Chlorine resistance. The uniqueness of this work was that the PVA polymer matrix was utilized as an active RO layer without the use of any polymeric or ceramic substrate. |
The present research was designed to investigate novel PVA RO membranes with various fillers and combinations and their effectiveness as active RO separation layers with improved biofouling and Chlorine resistance. The uniqueness of this work was that the PVA polymer matrix was utilized as an active RO layer without the use of any polymeric or ceramic substrate. The utilization of the RO membranes without the use of a substrate reduces negative consequences, such as internal concentration polarization that causes an increase in the applied RO pressure. Although PVA possesses excellent separation and film-forming properties, researchers tend not to use PVA as an active layer in RO applications because of PVA swelling and its possible rupture under high pressure. Instead, they utilize PVA as a modifier. The results of this investigation showed that the fabricated RO membranes overcame those issues through appropriate crosslinking and through an appropriate selection of fillers.
The crosslinked PVA RO membranes incorporated with various fillers like MWCNTs, ZnO Nano-particles, Gum Arabic, Vanillin, and others were fabricated using the dissolution casting method. The fabricated membranes were then characterized and analyzed using various techniques like attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), contact angle measurements, X-ray diffraction (XRD), scanning electron microscope (SEM), atomic force microscope (AFM) and mechanical testing. The actual reverse osmosis performance of the membranes, including permeation testing, salt rejection, and Chlorine resistance was examined using a reverse osmosis permeation unit.
This study showed that the incorporation of Pluronic F127 and various fillers into the PVA polymer matrix improved the overall RO performance of the membrane in terms of hydrophilicity, surface roughness, water permeability, salt rejection, Chlorine resistance, and biofouling resistance. All membranes provided superior salt rejection, Water Permeability, Chlorine and biofouling resistance, and mechanical strength.
As a final conclusion, the outcomes of this study have shown great promise for the proposed crosslinked PVA membrane as an active RO separation layer without a substrate. The results of this investigation showed that the fabricated RO membrane overcame PVA drawbacks through appropriate crosslinking and through an appropriate selection of fillers. The synthesized membranes had an improved RO performance and enhanced Chlorine and biofouling resistance.