Removal of atrazine and deisopropylatrazine front water by montmorillonite-phosphate crosslinked compounds

To assess the potential use of two montmorillonite-(cerium [Ce] or zirconiu m [Zr]) phosphate crosslinked compounds in removing organic pollutants from water, the adsorption of atrazine (6-chloro-N-2-ethyl-N-4-isopropyl-1,3,5- triazine-2,4-diamine) and one of the major metabolites of atrazine in water , deisopropylatran'ne (6-chloro-N-4-ethyl-1,3,5-triazine-2,4-diamine), has been studied at 25 degrees C using batch experiments. The influence of the presence of 0.01 M KCl in the medium was also investigated for a better und erstanding of variables affecting the adsorption of these organic compounds . Experimental data points have been fitted to the Langmuir equation, with the results indicating a higher adsorption for deisopropylatrazine than for atrazine on both adsorbents in saline and nonsaline medium. Variation of t he uptake of atrazine and the metabolite in the solution of 0.01 M KCl show s an enhanced adsorption of deisopmpylatrazine on both samples compared wit h that of atrazine. Fourier-transformed infrared (FTIR) spectroscopic studi es reveal that at the pH generated by the adsorbents (3.7 and 3.9 for Ce an d Zr-montmorillonite compounds, respectively), atrazine and its metabolite interact with the surface of the adsorbents. X-ray diffraction analysis sho wed that the compounds studied are intercalated into the adsorbents. For th e compounds considered, the cerium-montmorillonite adsorbent shows a higher capacity of adsorption compared with zirconium-montmorillonite adsorbent s o it might be particularly useful in removing atrazine and, to a greater ex tent, deisopropylatrazine from water.