Bamboo charcoal modified with Cu2+ and 3‐aminopropyl trimethoxy silane for the adsorption of acid fuchsin dye: Optimization by response surface methodology and the adsorption mechanism

Abstract

ABSTRACTThe bamboo charcoal modified with Cu2+ and 3‐aminopropyl trimethoxy silane (BC‐Cu/Si‐NH2) was synthesized and characterized by X‐ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersive spectroscopy, and surface acid–base potentiometric titration. The adsorption for acid fuchsin (AF) dyes onto BC‐Cu/Si‐NH2 was investigated. Moreover, response surface methodology was performed to optimize the process parameters including pH, initial dye concentration, adsorbent dosage, and temperature. The results presented that the adsorption process was mainly influenced by initial AF concentration and adsorbent dosage. Isotherm studies revealed that the adsorption data fitted well with the Sips model and Dubinin–Radushkevich (D–R) model, which indicated the monolayer, homogeneous, and physical nature of the adsorption process. The maximum adsorption capacity calculated from D–R model could approach approximately to 14.91 mg g−1 at 40 °C, and the maximum adsorption capacity of Sips reached to 10.77 mg g−1 at 40 °C. The kinetic experimental data matched well with Spahn and Schlunder model as well as pseudo‐second‐order model. In addition, intraparticle diffusion was not the only rate‐controlling step of adsorption process. Thermodynamic parameters revealed the feasibility, spontaneity, and endothermic nature of adsorption. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47728.