Adsorption of Acetochlor Herbicide on Inorganic- and Organic-Modified Bentonite Monitored by Mid-Infrared Spectroscopy and Batch Adsorption

Abstract

The results of sorption of acetochlor herbicide with different concentrations (1–15 µg/mL) in inorganic- and organic-modified bentonite are presented. Acetochlor sorption in both bentonite types was studied by attenuated total reflectance spectroscopy in the mid-infrared region and by batch equilibrium method. Infrared spectroscopy results suggest that the interaction of acetochlor with inorganic (or organic) bentonite takes place by mechanism involving the carbonyl stretching vibration and phenyl ring in the acetochlor molecule. The increase of the acetochlor concentration results in red shift of both corresponding band wavenumbers. Batch adsorption study pointed out more expressed sorption of acetochlor in organic bentonite.

Keywords:

• acetochlor
• batch-adsorption
• bentonite
• mid-infrared spectroscopy

Acknowledgments

The comments and suggestions raised by two anonymous referees and by Editor-in-Chief, Prof. Robert M. Michel, helped to increase the quality of the manuscript and are appreciated. We thank Georgios D. PhD Chryssikos, Laboratory of Theoretical and Physical Chemistry Institute of the National Hellenic Research Foundation for the set of all the samples and helpful suggestions.