STUDY ON THE ADSORPTION OF VERMICULITE TO Cd~(2+)

The adsorption of Cd 2+ on vermiculite were studied by experiment. The effects of agitating time,dosage,pH value,ion concentration,etc. on adsorption process were investigated. Results showed that vermiculite had a stronger adsorption capacity to Cd 2+ ;The adsorption process was quick,pH value was the main factor to effect adsorption,when ion concentration was constant,it is not beneficial to the adsorption of vermiculite when pH was lower than 4.0,the best suitable pH scope for vermiculite to adsorb Cd 2+ was neutral or alkali scope when pH was higher than 4.0. The mechanism that vermiculite adsorbed Cd 2+ was studied,Langmuir and Freundlich adsorption equations were suitable to the adsorption of Cd 2+ ,ion exchange was the main form of adsorption.