Abstract: In order to solve the low adsorption capacity of natural zeolites to heavy metals in wastewater, six kinds of modified zeolites were prepared and the adsorption properties of modified zeolites to hexavalent chromium ions were investigated. Among the six modified zeolites, H2 SO4/CuSO4 composite modified zeolite has the best adsorption performance to chromium. The adsorption curve of chromium is in accordance with Freundlich equation. Its adsorption intensity is 8 times that of natural zeolite. The adsorption kinetic curve accord with the second-order kinetics model. The results show that ion exchange plays an important role in the adsorption of hexavalent chrome ion, which is very close to the theoretical value.

Key words: modified zeolite;chromium;adsorption characteristic