Adsorption of Rhodamine B, methyl Orange, and phenol separately in aqueous systems by magnetic activated carbon: Optimization by central composite design

Abstract

In the current study, a novel magnetic activated carbon was synthesized for efficient removal of both anionic methyl orange, cationic Rhodamine B and Phenol fromcontaminatedwater. The adsorbent was characterized by different technique. The investigation of the adsorption properties of magnetic activated carbon was studied by central composite design (CCD) coupled with response surface methodology (RSM). The optimal conditions were established as follows: dye concentration of Coat 30 mg/L, dosage at 0.8 g/L, and pH of the adsorbate solution adjusted to 4.5. The different kinetic and isotherm models were applied to fit the experimental results, and it was observed that the Pseudo-second-order kinetics and Langmuir adsorption isotherm were the best-fitted models. The maximal monolayer adsorption capacities of the adsorbent were found to be 101, 218 and 135 mg/g for phenol, methyl orange, and rhodamine B, respectively. The synthesized MAC had outstanding durability and reusability, as seen by the removal rate that persisted over 80 % following four adsorption-oxidation cycles.The advantages of facile synthesis, cost-effectiveness, non-toxicity, strong adsorption capabilities for methyl orange, Rhodamine B and Phenol, and easy separability with an external magnetic field make magnetic activated carbon novel.