Simultaneous removal of 2,4-dichlorophenol and Pb(II) from aqueous solution using organoclays: Isotherm, kinetics and mechanism

In this paper, the sorption of 2,4-DCP onto DK4 (modified with dioctadecyldimethylammoniumchloride (DDAC)) was 3–5 times more than when using Na-bentonite, while sorption of Pb(II) on DK4 was not different from using Na-bentonite. Sorption isotherms for 2,4-DCP and Pb(II) were well described by the Langmuir isotherm (R2 > 0.99), while pseudo-second-order kinetic model provided good kinetic data fitting (R2 > 0.99). Furthermore, DK4 was characterized by SEM–EDS, XRD and FTIR, it is concluded that the co-sorption of 2,4-DCP and Pb(II) onto DK4 occurred through the partition mechanism for adsorbing 2,4-DCP and the ion-exchange mechanism for the sorption of Pb(II).