Decontamination of methylene Blue from simulated wastewater by the mesoporous rGO/Fe/Co nanohybrids: Artificial intelligence modeling and optimization

Decontamination of dye wastewater by nanomaterials has attracted an increasing attention. The mesoporous rGO/Fe/Co nanohybrids prepared by the co-precipitation method were used to decontaminate methylene blue (MB) from simulated wastewater. The obtained products were systematically characterized with X-ray diffraction, scanning electron microscopy, Raman spectroscopy, energy dispersive spectroscopy, N2-sorption, and X-ray photoelectron spectroscopy. It was found that these nanohybrids possessed a surface area of 108.445 m²/g and a narrow pore size distribution with a center of 3.94 nm. The effect of initial pH, temperature, contact time, initial concentration on the extent of decontamination by the material was investigated and modeled with artificial intelligence (AI). AI has become an important driving force for a new round of scientific and technological revolution and industrial transformation, which can achieve the overall improvement of social productivity. The optimum conditions were predicted and the maximum decontamination efficiency obtained by response surface methodology and AI, i.e. artificial neural network-particle swarm (ANN-PSO), artificial neural network-genetic algorithm (ANN-GA). Among the three models developed, the ANN-PSO model has the highest R2 value and the lowest MSE value, thus this model has the best performance. The experimental equilibrium data were analyzed with Langmuir, Freundlich, Tempkin and D-R isothermal models. It was exhibited that the data were well presented by Langmuir model with a maximum adsorption capacity of 909.10 mg/g at 298 K for the model. The kinetic study demonstrated that the decontamination processes could be well described by the pseudo-second-order model. In addition, thermodynamic parameters were calculated, which include Gibbs free energy change (ΔG°), entropy change (ΔS°), and enthalpy change (ΔH°). Overall, this material could be potentially used as a low cost and fast decontaminant to treat organic contaminants in wastewater or other pollutants.