Abstract: Mine wastewater contains cadmium and other heavy metal ions， which are highly toxic， and its direct discharge will cause serious pollution to the surrounding water and soil and harm human health. Tailings algae（Didymogenes palatina XR）， which is of heavy metal ion tolerance， isolated from lead-zinc mine tailings mixed with montmorillonite and then the mixture were regarded as research object to explores the adsorption effect for Cd（Ⅱ） removal in simulated mine wastewater. The surface characteristic of algae-montmorillonite system was observed by scanning electron microscope， and the function types of the samples were determined by the FTIR and XPS and adsorption mechanism was analyzed. The results showed that the saturated adsorption capacity of single tailing algae and montmorillonite is 97.21 mg/g and 40.57 mg/g when the solution pH is 5.5. Under the same experimental conditions， the saturated adsorption capacity of tailings alga-montmorillonite system with a mass ratio of 1∶5 is 60.07 mg/g， which is 20.12% higher than the theoretical adsorption capacity of 50.01 mg/g. The characteristic groups on the surface of tailings algae cells played a crucial role in the process of fixing cadmium in the system， and the phosphorus-related groups not only participated in the fixing of cadmium in the system， but also participated in the formation of tailings alga-montmorillonite system. Mixing the tailings algal with montmorillonite and using the samples for the removal of Cd （II） in the simulated wastewater， not only improved the maximum adsorption capacity of the sample for Cd （II） removal， but also enhances the repairation stability in the process of mine wastewater. The results is of great significance in the repairation of wastewater containing cadmium.

Key words: tailings algae, montmorillonite, Cd（II）, adsorption and fixed, mechanism analysis