Utilisation of thyme leaf and stem encapsulated alginate hydrogels prepared by microsyringe pump in lead(II) adsorption process

Abstract

In this study, new composite adsorbents were prepared from Origanum onites stems and leaves encapsulated in alginate beads and used for the removal of Pb(II) from synthetic aqueous solution. Effects of various parameters such as pH, temperature, initial lead concentration and contact time on the biosorption process have been investigated. Maximum uptake of Pb(II) ions (91%) has been achieved at pH 4 and 288.15 K with 25 mg/l of initial concentration. Among the applied isotherm models, the data correlated well with the Freundlich and D-R models and it was established that the biosorption was physical in nature. The amount of adsorbed lead per gram of sorbent was found to be 0.5107 and 0.6797 mmol/g for thyme leaves and stems based biocomposites, respectively. Thermodynamic parameters showed the endothermic character of biosorption and the feasibility of the process. The obtained results have indicated that the prepared biocomposites could be useful and effective alternative for lead biosorption. © 2021, Scibulcom Ltd. All rights reserved.