CADMIUM ADSORPTION IN DIFFERENT SUBSTRATA - INFLUENCE EXERTED BY CA

A series of interaction experiments were carried but between different substrata (soils and sewage sludge) with the aim of assessing Cd rete ntion in these substrata. We also studied the effect that the presence of Ca can have in Cd retention process. The data obtained were adjust ed to different adsorption isotherms (Langmuir's, Brunauer's and Freun dlich's), which led to different characteristic parameters. Langmuir's isotherm is the one that best describes the data obtained, with Freun dlich's model for the acid soil used. Increasing ionic strength with C a seems to promote a decrease in Cd adsorption.