Removal of methylene blue dye from aqueous solution by nonliving lichen (Pseudevernia furfuracea (L.) Zopf.), as a novel biosorbent

Abstract

The use of lichens is insufficient in industry. To the best of our knowledge, there is no study on the use of lichens in the removal of dyes from aqueous media. The aim of this study is to draw attention to the biosorption capabilities of lichens which are natural, renewable and inexpensive sources, and to investigate the usability of nonliving lichen Pseudevernia furfuracea (L.) Zopf. (LPF) in methylene blue (MB) dye removal from aqueous solution. With the green chemistry approach, no chemical treatment was applied to the LPF and it was used as a natural biosorbent for the biosorption. The LPF samples were prepared and characterized and performed batch mode biosorption experiments studying the effect of various parameters on MB biosorption. The experimental data were fitted with four different kinetic models (pseudo-first order, pseudo-second order, Elovich model and intra-particle diffusion) which were evaluated for their validity. Identification of the biosorption mechanism of MB onto the LPF was performed by isotherm studies via three isotherm models [Langmuir, Freundlich and Dubinin-Radushkevich (D-R)], and the parameters of each model were determined. It was concluded that the biosorption rate and yield were high, the type of biosorption of MB onto the LPF was defined as chemical biosorption, and the surface of the LPF was decided energetically heterogeneous. The results indicate that the LPF biomass can be attractive options for MB dye removal from aqueous media.