Studies on the adsorption of Pd 2+ ion by Nitzschia hantzschiana Rabh., a diatom were carried out. Uniform design was used to arrange the experiment. The growth period of diatom, adsorption time, concentration of Pd 2+ and pH were found to have positive effects on the adsorption amount of Pd 2+ on diatom. The optimum conditions are: the growth period of diatom 12 days, adsorption time=6 h, \=0.01 g/L and \ =0.16 mol/L. EPMA analysis showed that the diameter of the reduced adsorbed Pd was about 1 μm. A mathematical model was found to describe experimental data, that the adsorption fits to Freundlich equation, Q=70.2\ 0.76. The adsorption amount of Pd 2+ on diatom increased logarithmically with the increase of Pd 2+ concentration.
