Comparison of new biosorbents based on chemically modifiedLagenaria vulgarisshell

Sorption characteristics of three Lagenaria vulgaris-based biosorbents: raw biomass (rLVB), acid–base-activated biomass (aLVB) and sulfuric acid-treated biomass (ccLVB), were compared as a function of contact time, initial methylene blue concentration, and initial pH, in order to evaluate the effect of chemical modifications. The adsorption studies of raw and chemically modified L. vulgaris biomass were compared in batch mode. The Fourier transform Infrared spectroscopy (FTIR) results of biosorbents’ characterization showed presence of different functional groups which can be responsible for sorption of MB from aqueous solutions. Moreover, FTIR analysis reveals that acid–base activation of raw biomaterial resulted in hydrolysis of esters providing more reactive sites (–COO−), while sulfuric acid-treatment method introduced new functional groups such as –SO3−. Surface functional groups containing oxygen, such as carboxylic, lactonic, and phenolic, are quantified using the Boehm’s method. The kineti...