Effect of sodium stearate and sodium palmitate concentration on the modification of caal-layered double hydroxides for the removal of carbaryl and imidacloprid from aqueous solutions

Sodium stearate (SS) and sodium palmitate (PS), natural surfactants suitable for human consumption, were used to modify Ca- Al layered double hydroxides (CaAl-LDH) to evaluate their applications in synthesizing an adsorbent material for the removal of carbaryl and imidacloprid from contaminated water. CaAl-LDH materials were produced by the co-precipitation method. Modification of CaAl-LDH was performed with different degree of SS and PS saturation to determine the effect of surfactant concentration in pesticide removal efficiency from aqueous solution. Materials were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and energy dispersive spectroscopy (EDS). CaAl-LDH modified with PS at a concentration of 0.01 mol L^-1 had the highest removal efficiency for both pesticides with improved sorption capabilities three times greater than the inorganic LDH. This novel material exhibits an increase in the basal spacing for the (002) diffraction plane from 8.62 Å in the inorganic LDH to 8.75 Å, along with a well-crystallized phase, a good double layered structure, and hydrophobic properties. Further adsorption studies are required to achieve a better understanding of this material as an adsorbent of carbaryl and imidacloprid from contaminated waters.