An experimental time-dependent method for the study of atrazine sorption onto a characterized soil

Abstract

This work focused on the sorption/desorption of atrazine in aqueous soil suspensions. Soil used in this study was extracted from Northport (N.S.) and was chemically and physically characterized in-house. The soil acidity was determined to be at pH 4.7 and mass percent concentration of carbon, hydrogen, and nitrogen was 1.86%, 0.48%, and 0.34%, respectively. The mineral composition of the Northport soil consisted mainly of silica (SiO[subscript 2], 67%). Scanning Electron Microscopy analysis showed that the most abundant elements were Si (30.61%), O (47.94%), Al (9.80%), Fe (5.68%), and Mg (2.06%). Time-dependent sorption curves of atrazine were measured at constant temperature of 20°C using an off-line and an on-line separation technique with High Performance Liquid Chromatography. The sorption experiment showed that 66% of atrazine remained in solution, 6% of atrazine was labile sorbed onto the soil, and 28% of atrazine was unrecoverable and lost from solution during the first hour of sorption. Sorption kinetics results shows that after one full day of sorption, 20% of atrazine remained in solution, 32% was labile sorbed or extractable, and 48% of atrazine was unrecoverable.