Comparisons of porous, surface chemistry and adsorption properties of carbon derived from Enteromorpha prolifera activated by H4P2O7 and KOH

摘要

Enteromorpha prolifera based-activated carbons were prepared using chemical activation by H4P2O7 (PAC) and KOH (KAC) and applied as a potential adsorbent for the adsorption of acid scarlet (GR). N2 adsorption-desorption isotherms, scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), X-ray photoelec-tron spectroscopy (XPS) and Boehm titration were used to compare the porous structure, surface chemical property and adsorption behavior of carbon. KAC presented higher surface area (3500 m~2/g) and larger total pore volume (2.872 cm~3/g). To account for the adsorption mechanisms, the kinetic models, including pseudo-first-order model, pseudo-second-order model, intraparticle diffusion model and Boyd model were introduced. The Langmuir isotherm model was better fitted with the equilibrium data than Freundlich and Dubinin-Radushkevich models. The maximum adsorption capacities of GR onto KAC and PAC were 2500 mg/g and 454 mg/g, respectively. The physical adsorption and ion-exchange were the dominating adsorption mechanism.