In order to understand the adsorption of mineral and its modified products to herbicides,bentonite and appapulgite were used as the raw materials,and cationic surfactant hexadecyl trimethyl ammonium bromide (CTAB) was used to modify the bentonite and appapulgite.The organically modified minerals were prepared with the ratios of ECE/n(CTAB)=1∶1 and 1∶0.5,respectively.The equilibrium batch of chlorsulfuron adsorption on mineral and its modified products was investigated.The effects of pH and temperature on the adsorption of chlorsulfuron in the tested minerals samples were studied.The FTIR spectra of minerals modified with or without CTAB were characterized.The results showed that when the minerals were modified with CTAB,their adsorption capacities of chlorsulfuron were more than those of the original minerals significantly.The ability to adsorb chlorsulfuron of the 6 minerals samples was in the order of 1∶1 modified bentonite>1∶1 modified appapulgite>1∶0.5 modified bentonite>1∶0.5 modified appapulgite>unmodified bentonite>unmodified appapulgite.For example,at pH=7 and t=30℃,the maximum adsorption amount of 1∶1 modified bentonite,1∶1 modified appapulgite,1∶0.5 modified bentonite,1∶0.5 modified appapulgite,unmodified bentonite,and unmodified appapulgite was 3 930,2 667,979.0,3 991,3 029 and 1 505 mg/kg,respectively.It is concluded that the adsorption capacity of 1∶1 modified minerals was greater than that of 1∶0.5 type modified minerals.The adsorption capacity of bentonite and its modified minerals to chlorsulfuron was greater than that of the appapulgite.It also showed that the adsorption ability of organic modified minerals to the chloride was much better than that of the original minerals.The amount of adsorbed chlorsulfuron in the tested sample was gradually decreased with the increase of the solution pH.The amount of adsorbed chlorsulfuron in the tested samples increased with the increase of temperature as well.Adsorption thermodynamic was conformed to Freundlich isothermal adsorption model.It is indicated that the adsorption was spontaneous and exothermic process.It will provide scientific reference for the application of modified minerals in the field experiment on slowrelease pesticides and the organic pollutants removal in environment.