Abstract
Surfactants are considered as beneficial chemical additives in enhanced oil recovery due to their capability of reducing the interfacial tension and altering the wettability. However, the loss of surfactant by adsorption on the surface of the porous rock is one of the significant drawbacks of surfactant flooding. The mechanism, equilibrium, and kinetics of adsorption of a natural surfactant derived from the weed, Eichhornia crassipes, on sandstone and sand surfaces have been investigated through batch experiments at different concentrations (i.e., 1000-5000 mg dm
−3
), temperatures (i.e., 298-333 K), and a fixed salinity [NaCl (76.2%), CaCl
2
(3.7%), MgCl
2
(1.5%), and Na
2
SO
4
(18.6%)]. The mineralogy and morphology of the adsorbent samples were examined by the XRD and SEM analyses. The mechanism of surfactant adsorption and maximum adsorption were determined by various isotherms and kinetic models.
for adsorption on sandstone and sand was found to be −21.48 and −20.80 kJ mol
−1
, respectively.