Removal of Astrazone Blue from aqueous solutions onto brown peat. Equilibrium and kinetics studies

International audienceThe aim of this study is to characterize and assess the sorption potential of brown peat, in relation to colored pollutants from the textile industry wastewater. The objectives of this paper were: the physicochem., morphol., and mineralogical characterization of brown peat, testing the adsorption capacity of natural and chem. treated peat samples for Astrazone Blue, evaluation of adsorption process from equil. isotherm and kinetic point of view. The characteristics of the peat samples were investigated using elemental anal., SEM and X-​ray diffractometry. Exptl. data indicated that the brown peat tested confirm a high level of adsorption (removal efficiency >93.00​%, adsorption capacity reaching up to 24.27 mg​/g) of Astrazone Blue from aq. soln. The Langmuir and Freundlich adsorption isotherm models were used to find the best equation able to describe the adsorption process. Exptl. adsorption data were successfully described by the Langmuir equil. isotherm model. This fact is supported by the agreement between the q values obtained using the Langmuir equation (26.32 mg​/g)​, and the ones obtained exptl. (24.27 mg​/g)​. The kinetic studies showed that the pseudo-​second-​order model described Astrazone Blue sorption kinetics, as confirmed by the high values of R, which are over 0.99 for the whole investigated concn. range (200 to 800 mg​/L)​. The use of brown peat adsorbent is more advantageous compared with other materials since it does not require a preliminary treatment, is low-​cost and is an eco-​friendly adsorbent. Hence, this peat appears to be a viable material for the decontamination of effluents contg. dyes