This work aims at investigating Fe3O4-coated nanofibers based on cellulose acetate (CA) and chitosan (CS) for adsorption of Cr(VI), Ni(II), and phenol from aqueous solutions. The synthesized Fe3O4 nanoparticles (NPs), and the modified nanofibrous adsorbents are characterized by using FTIR and FE-SEM analyses. The optimum conditions for independent parameters such as adsorbent dosage, pH, contact time, and initial concentration of the adsorbates on the maximum removal of Cr(VI), Ni(II), and phenol are evaluated using the samples with and without Fe3O4 NPs. On the basis of kinetics and mechanism studies of the adsorption, pseudo second-order equation and Redlich-Peterson isotherm model show the best fitting on the experimental data. The obtained results revealed that the maximum monolayer adsorption capacities of Cr(VI), Ni(II), and phenol using Fe3O4-coated CA/CS nanofibers are 193.2 mgg(-1), 143.3 mgg(-1), and 163.5 mgg(-1), respectively. Also, the prepared adsorbents are reused and their performance is assessed for five adsorption-desorption cycles. Moreover, the adsorption of Cr(VI), Ni (II), and phenol in a ternary system is carried out. Finally, by comparing the adsorption outcomes, it is being found that the electrospun CA/CS hybrid nanofibrous sample coated with Fe3O4 NPs is a promising candidate for wastewater treatment potentially. (C) 2019 Published by Elsevier B.V.