Abstract：In this study, raw vermiculite has been modified by 2-aminoethanethiol (MEA) to obtain organo-vermiculite as adsorbent for the removal of silver ions in aqueous solution. The physicochemical properties of the raw and modified vermiculites were analyzed by Fourier transform infrared (FTIR) spectroscopy, thermogravimetry-differential scanning calorimetry (TG-DSC) and BET analysis, which indicated that MEA was successfully grafted onto the vermiculite. Additionally, batch adsorption experiments involving initial pH, adsorbent dosage, time and temperature demonstrated that the adsorption capacity of Ag+ onto MEA-VER was improved highly compared with that of raw vermiculite. The optimum adsorbent dosage was 2.0g/L, the adsorbents presented a high removal efficiency of Ag+ in a wide range of initial pH values (6-12). The kinetics studies showed that the adsorption process was described well with pseudo-second-order model and the equilibrium was achieved at about 200min of contact time. The adsorption isotherm of Ag+ onto vermiculites fitted the Langmuir model well. All these results indicated that the adsorption process onto vermiculites was taken place mainly by coordination and electrostatic adsorption .
