Abstract: The adsorption behaviors of Pb, Cd, Cu, Co and Ni onto natural suface coatings (biofilms and associated minerals, collected in the Nanhu Lake, Changchun, China) with and without competing metal ions were examined in this study. The results show that there is always competition between the two metals in the binary systems, especially between Ni and Co. In the system of all the five metal s present, the interference of adsorption among the five metals is more signifi cant than those in the binary systems. But for each metal, this reduction of adsorption capacity is less than the summary of the interfering effects of two metals calculated from the binary systems. The results also indicate that the adsorption sequence of these metals onto surface coatings in the five metal system is in agreement with that of in single metal system.

Key words: natural surface coating, heavy metal, adsorption, competition