The influence of co\|existing heavy metals on the adsorption of cadmium and copper onto solid phases was investigated by simulating aquatic multiphase system comprising three types of solid phases, including biofilms, suspended particulate materials and sediments, in the absence and presence of co\|existing heavy metals. The results indicate that co\|existing metals (copper and lead) reduced the adsorption of cadmium to all solid phases remarkably. Under the conditions of the adsorption of cadmium onto suspended particulate materials, the reduction effects increased as the initial concentration of copper and le
ad increased. Under the conditions of the adsorption of cadmium to biofilm and sediments, increasing lead initial concentration enhanced the reduction effects on cadmium adsorption, but increasing copper initial concentration had little influence on the reduction effects. The co-existing lead reduced the adsorption of c
opper to solid materials and these reduction effects increased with the increase of lead concentration for all the solid materials, while the co-existing cadmium had only a little effect on copper adsorption. Overall, the mpetitive adsorption between heavy metals was insignificant at low concentrations, and enhanced with the increasing of the concentration of co-existing heavy metals. The concentration of co-existing metals influenced the reduction of the adsorption of copper and cadmium to suspended particulate materials. The greater the concentrations of co-existing heavy metals were, the stronger the reduction of the adsorption of
cadmium and copper to suspended particulate materials was.