Adsorption of Cu (II) from aqueous solution on Sarkanda grass lignin: equilibrium and kinetic studies

Abstract

In this study, the adsorption of copper ions from aqueous solution onto lignin obtained from unmodified Sarkanda Grass was analyzed. To ensure optimal reaction conditions, the retention of copper ions was tested at different experimental parameters (pH of the initial solution and adsorbent, the dose of adsorbent, the concentration of aqueous solution and contact time). The experimental results have been interpreted using the classic Langmuir and Freundlich isotherms models, as well as two kinetic models (the Lagergren pseudo-first order and the Ho-McKay pseudo-second order models). Based on the analysis of the experimental data, it has been concluded that unmodified Sarkanda Grass lignin can be recommended as an efficient alternative, considering its practical applicability, in the retention of copper ions from aqueous solution, both in terms of the amount of adsorbent and pollutant specie retained, as well as in terms of adsorption time.