Biosorption study for removal of methylene blue dye from aqueous solution using a novel activated carbon obtained from nonliving lichen (Pseudevernia furfuracea (L.) Zopf.)

Abstract

To the best of our knowledge, there is no study on the utilization of lichens in the production of activated carbon while lichens are natural, renewable and cheap sources. In this study, a novel activated carbon (ACLPF) from non-living lichen Pseudevernia furfuracea (L.) Zopf. (LPF) was produced, and physicochemical and morphological characterization of the ACLPF were examined with the help of Brauner-Emmett-Teller surface area (BET), X-ray diffraction (XRD), Fourier transform infrared spectra (FTIR), thermogravimetric analysis (TGA) and scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDX) techniques. The obtained ACLPF had a high surface area (851.24 m(2)g(-1)) and a large pore volume (0.225 cm(3)g(-1)) with micropore size distribution (1.06 nm). To investigate the usability of the ACLPF in wastewater treatment, batch mode biosorption experiments were carried out, and the effect of various parameters on methylene blue (MB) dye removal from aqueous solution were studied. The experimental data were fitted with 4 different kinetic models (pseudo first-order (PFO), pseudo second-order (PSO), Elovich model (EM) and intra-particle diffusion (IDM)) and 3 different isotherm models (Langmuir, Freundlich and Dubinin-Radushkevich (D-R)). It was found that the maximum biosorption capacity and the removal efficiency (%) were as 243.9024 mgg(-1) and 91.38%, respectively. The biosorption of MB onto the ACLPF was chemical biosorption due to the activation energy (E-a) to be 42.63 kJmol(-1), and the process was endothermic (Delta H-0=61.4163 kJmol(-1)), feasible and spontaneous (Delta G(0)= -7.0278 kJmol(-1) at 318 K and Delta S-0 =0.1707 kJmol(-1)K(-1)) thermodynamically. The novelty of this study is that besides obtained and characterized the activated carbon (ACLPF) from the non-living LPF at the first time, the discussions on the biosorption capability of the ACLPF for the removal of MB dye from aqueous media are included in this paper.