Abstract:
Considering the negative effects of polluting species on the environment and human health, in particular heavy metals,
and the need for efficient use of resources, the present study investigated the adsorption of As (III) from aqueous
solutions under static conditions onto chemically unmodified Sarkanda grass lignin. In order to optimize the adsorption
process, the retention of As (III) was tested under various experimental parameters (pH of the initial solution and
adsorbent, concentration of aqueous solutions, adsorbent dose and contact time of the two phases). The experimental
data obtained were interpreted based on the classical models of Freundlich and Langmuir isotherms, which was useful
in establishing the equilibrium conditions and in evaluating the adsorption capacity for a solute. The adsorption
dynamics was studied using the Lagergren pseudo-first order and the Ho and McKay pseudo-second order models. The
analysis of the obtained experimental data recommends chemically unmodified Sarkanda grass lignin as a future
alternative adsorbent for water remediation, taking into account its practical applicability in the retention of As (III)
from aqueous solutions, in terms of both adsorbent and adsorbed doses, as well as the time required for adsorption.
