The DIFS (DGT induced fluxes in sediments and soils) model was used to simulate desorption kinetics of Cu from solid to liquid after depletion of DGT (diffusive gradients in thin films). Results show that the three samples used in the simulation were all in the same category of partial supply with R < 1, as the supply of Cu in solid form was not adequate to maintain the initial level of Cu concentration in the pore water at the interface of DGT. In Sample M1 (R=0.74), the distribution coefficient, Kd and desorption coefficient, k-1 were relatively high, and when DGT was in place for a given period of time, T, adsorbed Cu was rapidly desorbed to make Cu depleted, thus keeping the Cu concentration in the pore water at a constant value, which, however, was still lower than its initial value. In Samples M2 and M3, R, Kd and k-1 were all lower than in Sample M1, and its Cu supply in solid was also small, thus leading to decreasing Cu concentration of the pore water at the interface of DGT with the time of its placement, and a broader range of depletion of adsorbed Cu. The findings indicate that release of Cu from sediments is influenced jointly by the pool of bioavailable Cu and the kinetic parameters of the release. Sample M1, with steady partial supply is characterized by higher Kd and moderate k-1; whereas Samples M2 and M3 unsteady in partial supply by lower Kd and moderate or higher k-1.