The purpose of this study was to explore the potential of factionalized cellulose nanofiber (f-CNF) membranes to remove dissolved ions from water. The electrospun cellulose nanofiber (CNF) membranes were of interest to achieve the goal owing to their unique surface chemistry, abundance, biocompatibility, and a high-surface-area. The CNF have been successfully fabricated via deacetylation of cellulose acetate nanofiber (CANF) membranes followed by electrospinning of cellulose acetate (CA). The CNF membranes were functionalized differently for the very purpose, i.e., water desalination. The quaternized/cationic cellulose nanofiber (c-CNF) membranes were used for the adsorptive removal of anionic entities from the water. Similarly, carboxymethylated/anionic cellulose nanofiber (aCNF) membranes were utilized for the adsorptive removal of cationic substances from the water. The experimental studies revealed an improved adsorption capacity in the result of surface functionalization of CNF membrane over native CNF. The degree of quaternization and carboxymethylation was found to be 0.134 and 1.25 mmol/g of CNF, respectively. The physicochemical features of synthesized membrane were examined using different instrumental and analytical methods. The success of reactions was confirmed through Fourier Transform Infrared Spectroscopy (FTIR). The Scanning electron microscopy (SEM) was used to analyze the surface morphology of membranes. The wide distribution in the nanofiber diameter was found as the nanofiber diameters, which were in the range between 70 to 700 nm. The BET surface area analysis revealed 15.40, 5.40, and 13.5 m2/g specific surface areas for the CNF, c-CNF, and aCNF, respectively. The thermogravimetric analysis (TGA) was used to examine the thermal stability of membranes, which revealed that the native and functionalized CNF could endure up to 220 ℃. The mechanical stability of CNF membranes remained a challenge to-date, in this regard, the ionic cross-linking of c-CNF and a-CNF was attempted successfully. It has been achieved a 2.0, and 2.5 MPa improvements in the tensile strength in case of a-CNF and c-CNF membranes respectively.Finally, zeta-potential measurements were utilized to investigate the surface-charge densities over nanofiber surfaces at a wide range of pH values. xx This research was further extended to examine the adsorption behavior of the resultant membranes in the batch and continuous adsorption modes. In the batch study, experiments were conducted as a function of pH, adsorbent-adsorbate contact time, and initial concentration of targeted ions. On the other hand, experiments were performed as a function of bed-height (membrane layers), an initial concentration of the targeted ions, and the flowrate of the feed-solution in the continuous mode. This study exhibited that the adsorption performance of a-CNF is highly dependent on pH values. However, the pH of the solution slightly influenced the adsorption through the c-CNF membranes. The kinetic and isotherms modeling revealed that the Pseudo-second-order (PSO) kinetic and Langmuir adsorption isotherm were explaining well to the experimental data. On the other hand, adsorption in the continuous mode, Yoon-Nelson model and Thomas model were used to determine the membrane saturation time and adsorption capacity respectively. Furthermore, the experiments revealed that the Ca2+ and Mg2+ ions could be easily desorbed from the saturated aCNF, and SO42- ions could be easily desorbed from contaminated c-CNF through a washing procedure with diluted acidic and alkali solutions respectively. The quantitative values for the adsorption capacities were described as 24-mg/g for SO42-, 59-mg/g for Ca2+, and 75-mg/g for Mg2+ ions using f-CNF membranes in the batch mode. In contrast to CNF, the improved binding efficiency of cationic and anionic f-CNF membranes was linked to the grafting of ammonium and carboxymethyl groups over CNF. Furthermore, the adsorption capacities of f-CNF membranes for the synthesized ionic solution in the continuous mode were calculated as 1237-mg/g. Similarly, real-groundwater was also treated to determine the adsorption capacity, which was found to be 668-mg/g. In the continuous mode, both membranes were reused up to three adsorption-desorption cycles. The specific arrangement of functionalized nanofiber membranes was also another cutting-edge feature of this study, which can not only lead to contribute to scientific research but also has the potential to provide business opportunities.