Thin film nanocomposite loose nanofiltration membranes with graphene oxide interlayer for textile wastewater treatment

As a sustainable approach towards textile wastewater treatment, aimed at mitigating water pollution and recovering valuable resources, the development of loose nanofiltration (LNF) membranes is crucial. In this research, we fabricated a high-performance thin film nanocomposite (TFN) LNF membrane by utilizing graphene oxide (GO) - a 2D nanomaterial with favorable attributes, as an intermediate layer between the substrate and the polyamide (PA) layer that formed through the interfacial polymerization reaction between polyethyleneimine (PEI) and trimesoyl chloride (TMC). Characterization results revealed that employing GO brought about an alteration in the formed PA's physicochemical properties including its morphology, surface chemistry, and surface charge. The resulting GO-TFN membrane exhibits excellent pure water permeance at approximately 40 L m-2h- 1 bar- 1, along with exceptional salt/dye separation efficiency. It demonstrated a high rejection rate for various dyes such as the low-molecular-weight Disperse Blue 1 dye (MW=296.32 Da), exceeding 99 %, and low Na2SO4 salt retention of less than 10%. This high dye/salt fractionation capability renders the GO-TFN a suitable material for pollution control and resource recovery.