A comparison of three pesticides adsorption on silica and functionalized silica particles

AGUSTÍN SPALTRO; SERGIO LAURELLA; MARICEL CAPUTO; DIEGO COLASURDO; GERÓNIMO TACTAGI; DANILA RUIZ; PATRICIA E. ALLEGRETTI

Congreso; 13th Latin American Conference on Physical Organic Chemistry; 2015

Agrochemicals are extremely harmful substances to the environment. The abuse of these substances threatens living beings, so that different methodologies are designed to remove them from the environment. Among them, adsorption is a fast, economical and easy technique. The pesticides studied in this work were bentazone, imazapyr and MCPA. Bentazone (3-Isopropyl-1H-2,1,3-benzothiadiazin-4(3H)-one 2,2-dioxide) is a selective herbicide, highly toxic, belonging to the chemical group of benzothiadiazinones. MCPA (4-chloro-2methylphenoxyacetic acid) is a selective herbicide for control of broadleaf weeds in cereals and other crops. Imazapyr (2-(4-Methyl-5-oxo-4-propan-2-yl-1H-imidazol-2-yl)pyridine-3-carboxylic acid) is a non-selective herbicide that can persist in soil for over a year. It is corrosive to eyes (it can cause irreversible damage) and it disrupts protein synthesis interfering with cell growth and DNA synthesis. These pesticides are used in large areas of Argentina in Pampa and Patagonia. The silica used for adorption process has mesoporous pores. In order to modify the process of adsorption, adsorbent was chemically modified, and it was characterized by IR spectroscopy. The isotherm obtained were analyzed with various adsorption models: Langmuir, Freundlich and BET.