Herbicides pH Soil Kf (mg/Kg ) 1/n R2 Koc (mg/kg) Kom (mg/kg ) Simazine 5 A 1.6235 0.0376 0.9928 18.8779 11.8503 B 1.1610 0.2881 0.9926 55.2857 24.1875 7 A 1.1581 0.1496 0.9978 13.4662 8.4532 B 0.9138 0.3251 0.9868 43.5142 19.0357 9 A 0.5071 0.2296 0.9894 5.8965 3.7014 B 0.4994 0.3865 0.9874 23.7809 10.4041 Atrazine 5 A 1.4938 0.0024 0.9794 17.3697 10.9036 B 1.0956 0.2132 0.9878 52.1714 22.825 7 A 1.0113 0.2121 0.9889 11.7593 7.3817 B 0.8395 0.2865 0.9811 39.9762 17.4896 9 A 0.5459 0.3301 0.9744 6.3476 3.9846 B 0.6968 0.3231 0.9719 33.1809 14.5166

Table 3: The adsorption parameters of simazine and atrazine in agricultural soils at different pH. The values represent an average value of three independent experiments.