Adsorption removal of methylene blue onto activated carbon/cellulose biocomposite films: Equilibrium and kinetic studies

Abstract

Activated carbon/cellulose composite (ACC) biosorbent films were fabricated via solution casting by combining 1–3% w/v of activated carbon with the cellulose solution which dissolved by lithium chloride/N, N-dimethylacetamide. Both cellulose solution and activated carbon were prepared from sisal fiber. These films were characterized by scanning electron microscope (SEM), Fourier transform infrared spectroscope (FTIR), thermogravimetric analyzer (TGA), and X-ray Diffractometer (XRD). The specific surface area of activated carbon was found to be 1165 m2/g. The maximum methylene blue adsorption capacity of the ACC film reached 103.66 mg/g with the dye concentration of 100 mg/L, solution pH of 6.9, at 35○C for 24 h. The adsorption data suggested that the isotherm model for the equilibrium process was that of Langmuir model, and the adsorption kinetic was best described by pseudo-second-order model. The effect of initial dye concentration (20–100 mg/L), contact time (0–2,880 min), pH (3–11), and temperature (35–80○C) on adsorption capacity of ACC3 film were also examined. Thermodynamics studies of ACC3 film revealed that the adsorption process was endothermic, spontaneous, and feasible. Therefore, the activated carbon/cellulose composite films can be potentially used as biosorbents to remove dyes from contaminated water.