Optimizing Eriochrome Black T adsorption through In-Situ polymerization of Poly(aniline-co-formaldehyde) on biochar: Multivariate approach using full factorial Design, Box-Behnken, Artificial intelligence, and DFT

Abstract

Over the past few years, using organic–inorganic composites in wastewater treatment through adsorption has become increasingly widespread. The combination of activated carbon and polyaniline (AC@PANI) has garnered significant interest in these composites. This study introduces a novel type of coating known as poly(aniline-co-formaldehyde) (PAF), which is classified as a copolymer and exhibits crosslinking properties. Compared to polyaniline, PAF forms a three-dimensional network structure, a rapid process for the synthesis of AC@PAF. Moreover, PAF demonstrates a notable enhancement in adsorption capacity for the anionic Eriochrome Black T (EBT) dye. In this study, we coated activated carbon, previously activated using H3PO4 (ACNgG-P), with PANI and PAF. Our findings reveal that the PAF coating exhibits an exceptional adsorption capacity of 700.01 mg/g for EBT, surpassing ACNgG-P and ACNgG-P@PANI.Furthermore, the adsorption of EBT onto the surface of ACNgG-P@PAF was optimized and modeled using artificial intelligence (AI), specifically an artificial neural network (ANN). The ANN was employed to predict and maximize adsorption by analyzing the complex relationships between various parameters. Finally, the Density Functional Theory calculations were used to elucidate the adsorption mechanism by identifying the active sites on the surface of ACNgG-P@PAF and analyzing the molecular structure of EBT.