Adsorption behavior of ZJ1835 in soil

In order to evaluate the environment safety of ZJ1835, the adsorption-desorption experiments of ZJ1835 in five soil samples were conducted by the batch equilibration techniques. Data were analyzed by mathematic models, which described the characteristics and mechanism of adsorptiondesorption and the shift of ZJ1835 in soils. The results showed that the adsorption-desorption isotherms of ZJ1835 was well described by Freundlich model. The adsorption values Kf of ZJ1835 in 5 types of soil samples ranged from 6.991 to 18.49. The adsorption of ZJ1835 in five soil samples showed the following sequence:black soil > paddy soil > cinnamon soil > fluvo-aquic soil > red soil. The organic carbon adsorption coefficients (KOC) of ZJ1835 in five types of soil samples ranged from 704.4 to 1 579, which indicated the low mobility of ZJ1835 in soils. And the TLC experiments showed the mobility of ZJ1835 in soil was low. Moreover, absolute values of the adsorption free energy of ZJ1835 in the tested soils were lower than 40 kJ/mol, which indicated that the adsorption processes were mainly physical adsorption. Kf values increased with the increasing of organic matter (OM) and clay content, while it decreased with the increasing of the soils pH values. The results of desorption indicated that the hystersis phenomena appeared during the desorption process in three kinds of tested soil. In conclusion,no risk to surface water and underground water was expected with normal usage.