Abstract: Attapulgite(ATT) modified by the hydrochloric acid(HATT) was grafted by amino-silane coupling agent KH-792(N-beta-(aminoethyl)-gamma-aminopropyl-trimethoxysilane). Thermal behavior and the structure of the grafted HATT(KHATT) were characterized by FTIR, TGA, DSC, XRD and BET. The results showed that the KH-792 molecules were successfully grafted onto the HATT surface. The adsorption of Cr(Ⅵ) onto KHATT in stimulative water was also investigated. The results showed that removal rate of Cr(Ⅵ) in water was relatively high(85.15%) when the loading of KHATT is 3 g/L, pH of the water is 5.5 and the adsorption time of the KHATT is 40 min. The adsorption capacity of KHATT after four times regeneration retained at least 90% of the initial one, showing a high application value. In addition, an adsorption mechanism of KHATT for Cr(Ⅵ) was proposed.

Key words: attapulgite, silane coupling agent, modification, adsorption, regeneration