Fabrication and filtration of gum arabic doped electrospun PLA membrane for rejection of gray water pollutants

Water scarcity, which is increasing with global warming and climate change, is one of the environmental problems that require urgent solutions. Gray water treatment is one of the effective methods to address this problem. Gray water from washing machines can contain organic and inorganic pollutants. Electrospun nanofibers show promise in the removal of these pollutants owing to their high surface area and tunable properties. In this study, gum arabic (GA) doped polylactic acid (PLA) nanofiber membrane was produced by an electrospinning method for gray water filtration. GA is a functional and economical additive that complements the deficiencies of PLA and improves the hydrophilicity, mechanical strength, flexibility, and separation performance of the membrane. GA was added to the PLA membranes at 1-5%. The characterization tests revealed that GA doped membranes were successfully produced. In methylene blue filtration, the pure PLA membrane provided over 93% rejection, while this rate increased to 99% with GA additive. Emulsified oil removal was measured as 87% in the membrane with 2% GA additive. Approximately 50% rejection was achieved in linear alkyl benzene sulfonate (LAS) filtration and 100% in microplastic filtration. With GA additive, the surface contact angle decreased from 127° to 118° and hydrophilicity increased. In mechanical tests, the tensile strength of the PLA membrane without additives increased from 7 MPa to 11.8 MPa with 4% AG additive and the mechanical strength and flexibility increased significantly. In conclusion, GA doped PLA membranes are considered as an effective and sustainable option for gray water treatment. © 2025 Bulgarian Academy of Sciences, Union of Chemists in Bulgaria.