Ultra-cheap and ultra-stable adsorption materials based on nylon and removal performance of copper ion

•A novel adsorbent material, nylon@Fe3O4, was obtained by using nylon as substrate.•The optimum adsorption efficiency was 94.67 % and the optimum adsorption capacity was 11.57 mg/g.•The adsorption process of nylon@Fe3O4 on Cu(II) was spontaneous and favorable adsorption. A novel adsorbent material, nylon@Fe3O4, was prepared by co-precipitation of nylon and FeSO4/FeCl3/NaOH solution. The structure of the composite was characterized using FTIR and TG methods. The results of FTIR and TG indicated that nylon@Fe3O4 was successfully synthesized. The adsorption effect of nylon@Fe3O4 on Cu(II) was explored under different experimental conditions. The optimum adsorption conditions of nylon@Fe3O4 on Cu(II) were reached when the amount of composite was 12.50 mg, the concentration of Cu(II) was 15.36 mg/L, the reaction temperature was 50 °C, and the pH value was 9. Under the above conditions, the optimum adsorption efficiency was 94.67 % and the optimum adsorption capacity was 11.57 mg/g. The kinetic modeling indicated that the adsorption of nylon@Fe3O4 belonged to chemisorption, and the initial adsorption rate (h = 69.92 mg/g/min) was larger, which indicated that the nylon@Fe3O4 adsorption rate was faster. The adsorption isotherm experiments showed that the nylon@Fe3O4 adsorption process occurred in the monomolecular layer adsorption, and the separation coefficients 0