Activated carbon/metal-organic framework composite as a bio-based novel green adsorbent: Preparation and mathematical pollutant removal modeling

Herein, the novel green MOF's nanocomposite based on cucumber peel activated carbon (AC) and chromium-based metal-organic framework (MIL-101(Cr)) with different AC ratios (2, 5 and 10 wt%) was synthesized and used for removing Acid Green 25 (AG25) and Reactive Yellow 186 (RY186) dyes from the binary systems. The characterization of materials was done using TGA, BET, XRD, SEM, and FTIR. The SEM images of MIL-101 showed octahedral crystal structure and composite materials exhibited the same morphology as MIL-101(Cr) crystals on an activated carbon bed. The BET surface area of AC and AC/MIL-101(Cr)_5% was measured 1096.83 and 2412.1 m2/g, respectively. The results showed that the Response Surface Methodology (RSM) model predicted the actual data with high correctness. The reliability of the RSM model was validated by the high values of R2 (AG25: 0.961 and RY186: 0.957). The obtained data from this research are well-fitted with the Langmuir isotherm and the pseudo-second order kinetics. The desorption process indicates that the adsorption capacity changes are <9% after five cycles.