Column study of cadmium adsorption onto poly(vinyl alcohol)/hydroxyapatite composite cryogel

Macroporous PVA/HAp composite cryogel was studied for cadmium removal in a fixed-bed column. The cryogel was made through a freeze-thawing process. The morphology of the cryogel was measured. The adsorption performance of the cryogel in the column was examined by varying bed height and HAp amount in PVA cryogel. The maximum adsorption capacity and exhaustion time were determined from the breakthrough curves. The experimental data was described using Adams-Bohart model. Bed height did not exert a large influence on the maximum adsorption capacity and exhaustion time. The kinetic rate constant and the adsorption capacity of the bed were found to be affected by HAp amount.