Removal of Cu (II) from aqueous solutions using ZIF-8@GO composites

[email protected] (X ​= ​0, 2.48%, 4.07%, 7.83%, and 20.03%) composites were prepared using GO and ZIF-8. The composites were used to absorb Cu(Ⅱ) from aqueous solutions. With increasing GO content, the adsorption of the [email protected] composites first increased and then decreased. The Cu(Ⅱ) adsorption of [email protected]% reaches a maximum among [email protected] composites (X ​= ​0, 2.48%, 4.07%, 7.83%, and 20.03%). The adsorption kinetics, adsorption isotherm, adsorption thermodynamics, and adsorption mechanism of Cu (II) by [email protected]% were studied in this paper. The results showed that the adsorption reached equilibrium at 120 ​min, and [email protected]% approached equilibrium relatively quickly. When the temperature was 45 ​°C and the Cu(Ⅱ) concentration was 40 ​mg/L, the maximum adsorption capacity of [email protected]% for Cu(Ⅱ) reached 482.29 ​mg/g. The equilibrium data and kinetics were well described by Langmuir and pseudo-first-order models, respectively. Final experiments with real factory wastewater (initial Cu(Ⅱ) concentration of 670 ​mg/L) revealed that 0.37 ​g/L [email protected]% can efficiently reduce the Cu(Ⅱ) concentration to below 2 ​mg/L.