| dc.description.abstract | Iron-modifed raw kaolinite clay (Fe-MC) was synthesized by co-precipitation method, characterized, and then applied as a
low-cost adsorbent to sequester sulfachloropyridazine (SCP) and sulfadimethoxine (SDM), emergent water contaminants,
from aqueous media by batch equilibration at circumneutral pH. The adsorption rate was kinetically described by the pseudosecond-order model. Equilibrium monocomponent sorption data were ftted to three two-parameter linear and nonlinear
isotherm models. The data were best described by Temkin and Langmuir nonlinear equations. Linearization of adsorption
isotherms is demonstrated to be an unsuitable analytical tool for predicting adsorption isotherms. The Langmuir monolayer
maximum adsorption capacities were 4.561 and 1.789 mg/g for SCP and SDM, respectively. The binary adsorption study
showed an antagonistic adsorption process of SCP (Rq, SCP=0.625) in the presence of SDM (Rq, SDM =1.032). The thermodynamic parameters, namely enthalpy (ΔH), Gibbs free energy (ΔG), entropy (ΔS), Arrhenius activation energy (ΔEa), and
sticking probability (S*
), indicated that the processes are spontaneous, exothermic, and physical in nature. The adsorption
process was attributed to hydrogen bonding and negative charge-assisted H-bonding (CAHB). Using the Langmuir isotherm,
the amount of Fe-MC required for a given volume of efuent of known contaminant concentration could be predicted | en_US |
