Interactions of acidic herbicides bentazon and dicamba with organoclays

• Published in: Soil Science Society of America journal Vol. 68; no. 6; pp. 1863 - 1866
• Main Authors: Carrizosa, M.J, Koskinen, W.C, Hermosin, M. del C
• Format: Journal Article
• Language: English
• Published: Madison Soil Science Society 01.11.2004; Soil Science Society of America; American Society of Agronomy
• Subjects: Agronomy. Soil science and plant productions; ammonium compounds; Applied sciences; bentazon; Biological and medical sciences; Decontamination. Miscellaneous; dicamba; Earth sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Exact sciences and technology; Fourier transforms; Fundamental and applied biological sciences. Psychology; herbicide-organoclay complexes; Herbicides; hydrophobicity; Impact analysis; Infrared spectroscopy; ionizable organic pollutants; Montmorillonite; organoclays; Pollutants; Pollution; Pollution, environment geology; saturated alkylammonium cations; Soil and sediments pollution; Soil and water pollution; Soil contamination; Soil mechanics; Soil science; sorbents; Sorption; Water pollution; X-ray diffraction; USA, Arizona; Benzothiadiazine derivatives; Agricultural chemical product; Auxin; Physical chemistry; Hydrophobic interaction; Soil pollution; SOIL CHEMISTRY; Organic acids; Environmental engineering; BENTAZONE; Soil science; Silicate mineral; Xenobiotic; Organic compounds; Organic clay; Pesticides; Organomineral complex; Acidity; Phyllosilicate; Polar compound; Experimental study; Herbicide; Sorption; Pollutant; Water pollution; Phytohormone; Dicamba; Sorbent
• ISSN: 0361-5995; 1435-0661
• DOI: 10.2136/sssaj2004.1863

We determined the sorption mechanism of the acidic herbicides bentazon [3-(1-methylethyl)-1H-2,1,3-benzothiadiazin-4(3H)-one 2,2-dioxide] and dicamba (3,6-dichloro-2-methoxybenzoic acid) on two organoclays, octadecylammonium (ODA)- and hexadecyltrimethylammonium (HDTMA)-exchanged Arizona montmorillonite (SAz-1), as part of a study to determine their potential use as sorbent materials for ionizable organic pollutants. To determine the mechanisms involved in the sorption process, herbicide-organoclay complexes were characterized by x-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). In general, the d001 values of SAz-HDTMA and SAz-ODA organoclays expanded after herbicide saturation, indicating interlayer sorption of the herbicide. Also, FTIR spectroscopic studies suggested weak hydrophobic interactions between these herbicides and the interlayer organic phase of the organoclays. However, H bonding between these herbicides and the monosubstituted amino group in SAz-ODA reinforced the strength of the hydrophobic interactions resulting in nonreadily reversible sorption on that organoclay. These results suggest that organoclays can be used to remove this type of pollutants from water or soils.