Novel polymeric membranes based on green reduced graphene oxide for the nanofiltration of emerging contaminants from water in a ternary system

[Display omitted] •g-rGO was prepared by a green route using carrot extract;•hPAN@g-rGO can be applied to filtration and adsorption processes;•g-rGO constricted the finger-like sublayer and increased membrane roughness;•The increase of g-rGO improved the adsorption of contaminants by 50%-150%;•The removal mechanism was based on π-π interactions and hydrogen bonding. Polymeric membranes containing reduced graphene oxide (rGO) have demonstrated efficacy in the remediation of contaminated water. The objective of this study was to examine the impact of the morphological and physicochemical properties of polyacrylonitrile membranes (hPAN) containing rGO on their filtration and adsorption performance. The rGO was prepared via a green route (g-rGO), and the filtration experiments applied the removal of emerging contaminants in a ternary system that simulates real conditions. The incorporation of g-rGO into the membrane resulted in the formation of a thinner finger-like sublayer, an increased in the membrane’s roughness, and an enhancement in the pure water flux. The batch experiments revealed adsorption rates of 72%, 55%, 75%, 96%, and 80% for ciprofloxacin (CIP), moxifloxacin (MOX), and levofloxacin (LEV), Cu(II) and Zn(II), respectively. The adsorption rate for CIP and MOX increased by 151% and 87.5%, respectively, in comparison to the pristine hPAN membrane. In the filtration experiments conducted in a ternary system, the membrane hPAN@g-rGO5 exhibited a rejection rate of 62%, 59%, and 68% for acetaminophen, atrazine, and sulfamethoxazole, respectively. The density functional theory (DFT) study indicated that sulfamethoxazole was the most removed emerging contaminant of the ternary system, primarily due to its higher size and the presence of π-π interactions and hydrogen bonding.