KINETICS OF ADSORPTION OF HUMIC MATTER ON MERCURY

Simulations of theta vs t(1/2) curves for an unstirred medium and an e lectrode of constant area were set assuming that the global adsorption process of humic matter on mercury is controlled by both steps, diffu sion and adsorption kinetics at the interface. Experimental theta vs t (1/2) results obtained by alternating current voltammetry for differen t concentrations of humic matter at pH 2.5 and pH 5.0 were successfull y fitted to theoretical curves if an association reaction of humic mat ter at the surface of the electrode and repulsive interactions that st rongly affect high 8 values were considered after a certain degree of surface coverage.