Adsorption of non-ionic pesticide S-Metolachlor on layered double hydroxides intercalated with dodecylsulfate and tetradecanedioate anions

The objective of the present research was to investigate the adsorption of non-ionic pesticide S-Metolachlor on two different organohydrotalcites (OHTs): one intercalated with dodecylsulfate (HT-DDS) and the other one with tetradecanedioate (HT-TDD) anions, both of them obtained by the coprecipitation method. The adsorbents and the adsorption products were characterized by X-ray diffraction and FT-IR spectroscopy. The results indicated that the adsorption of S-Metolachlor on the organohydrotalcite HT-TDD was higher than that on HT-DDS, but desorption was lower. The amount of S-Metolachlor adsorbed increased with temperature, especially for HT-TDD. S-Metolachlor desorption from HT-DDS and HT-TDD was characterized using two experimental procedures, which indicated the higher reversibility of S-Metolachlor adsorption from HT-DDS compared to HT-TDD. The results suggest the possibility to use both organohydrotalcites uptaking S-Metolachlor from contaminated water.