New Biosorbent Based on Al2O3 Modified Lignocellulosic Biomass (Lagenaria vulgaris): Characterization and Application

A new biosorbent, obtained by chemical modification of lignocellulosic biomass with Al2O3, was tested for removal of anionic surfactant sodium dodecylbenzenesulfonate (DBS) from aqueous solution in batch conditions. As a basic lignocellulosic material for chemical modification by Al2O3 was used Lagenaria vulgaris shell (LVB). Biosorbent characterization was performed by Fourier transform infrared spectroscopy, scanning electron microscopy with energy dispersive X-ray spectroscopy, and X-ray diffraction analysis. Obtained matter showed significant improvement of removal efficiency compared with unmodified biomass. Effect of initial pH value, biosorbent dosage, and initial concentration of DBS on the sorption process was studied. Sorption of DBS onto LVB-Al2O3 was highly pH dependent. Complete DBS removal was attained at lower pHs; as pH increased up to 9, DBS removal rapidly decreased. Optimal sorbent dosage was 2g/dm(3). Sorption kinetics followed pseudosecond-order, intraparticle diffusion and Chrastil's models, suggesting that both surface reaction and diffusion were rate-limiting steps. Equilibria experimental results were best fit by Langmuir sorption isotherm models. Maximum sorption capacity of LVB-Al2O3 for DBS was found to be 513.28mg/g. The present study suggests that the chemically modified L. vulgaris shell with Al2O3 could be used effectively for the removal of DBS from aqueous solution.