Ibese watershed has been experiencing lower water quality due to industrialization. Polyethylene terephthalate (PET)-graphene oxide (GO) nanocomposite membranes (M1, M2 and M3) synthesized by non-solvent-induced phase separation on polyester nonwoven support using polyethylene glycol (PEG) as additive was reported. The membranes (M1, M2 and M3) were respectively synthesized with 1wt%, 2wt% and 3wt% GO. The morphology of the membranes was characterized by scanning electron microscopy (SEM). ImageJ software was used to study the pore size distribution of the membranes. Python was use for the statistical study using the uniform distribution curve and mean and the results show that the radius data distribution is tightly clustered around the mean. The adsorption performance of composite membranes was examined for the removal of ions from the river water. The membranes were assessed through flux, adsorption capacity and the rejection of iron and anions found in Ibese river water. M3 membrane gave higher rejection rate for the three anions and iron. The % rejection of nitrate ion with M3 membrane is 96%, 85%%, 72% and 60% respectively for NO3−, Cl−, HCO3− and Fe. Increase in the quantity of GO increased water flux and the maximum water flux was attained with 3wt% GO.