An efficient adsorbent for the removal of dyes prepared by an in situ growth of ZIF-8 onto activated carbon

Electric arc furnace dust (EAFD), categorized as hazardous waste, contains notable concentrations of zinc. This research involved inducing the in situ deposition of zinc ions from EAFD on activated carbon (AC) surfaces, followed by the formation of ZIF-8 on the AC surface through the addition of 2-methylimidazole. The resulting ZIF-8/AC composite was utilized for adsorbing reactive and dispersed dyes. The characterization of the as-prepared ZIF-8/AC was accomplished by XRD, FT-IR, SEM, EDX, BET, XPS, and TGA. The as-prepared composite was tested for adsorption of reactive blue 19 (RB19) and chromatint yellow 3247 (CY3247) dispersion dyes. The ZIF-8/AC6 adsorbent produced the best removal efficiency for CY3247 (96.47%) and RB19 (98.63%). The highest removal efficiencies were 99.51 and 96.52% for RB19 and CY3247, respectively (concentration of 25 mg/mL). The Langmuir model yielded the maximum adsorption capacity (84.03 mg/g for RB19 and 72.46 mg/g for CY3247) coupled with strong correlation coefficient values. The Langmuir isotherm model was identified as the most fitting representation of equilibrium based on experimental data. The pseudo-second order rate model offers the most accurate depiction of the adsorption kinetics, and the Langmuir model proves suitable for describing the adsorption of RB19 and CY3247 on ZIF-8/AC.