Adsorption kinetics of diazo-dye from aqueous solutions by using natural origin low-cost biosorbents

Abstract

In the present study, the adsorption of diazo-dye onto natural origin low-cost biosorbents prepared from pyrolyzed petrified sediment (PPS), pyrolyzed sawdust from maple bark and chitin was investigated in aqueous solution. Trypan blue (TrB) was used as diazo-dye during the adsorption process. Effects of the operational parameters as contact time and type of adsorbents for the removal of TrB were studied using a batch process. The intraparticle diffusion model, the pseudo-first-order and the pseudo-second-order models were used to examine the kinetic data. Dynamic data of the dye adsorption were also fitted to the intraparticle diffusion model well. The order of the uptaken capacities of dye on these adsorbents was found as chitin > petrified sediment > maple sawdust. Langmuir, Freundlich, Temkin models were employed for fitting the equilibrium adsorption data of TrB. Langmuir and Temkin isotherms were found to represent the data best for the adsorption of TrB onto these adsorbents. The adsorption capacities of the adsorbents PPS, pyrolyzed maple bark sawdust and chitin were obtained to be 345, 72.5, 122 mg g(-1) at 298 K, respectively.