To better understanding the complicated oxidation/adsorption mechanism of mercury removal on surface of coal-fired fly ashes

the mercury adsorption tests were carried out on a fixed bed reactor.Moreover

apparent adsorption kinetics models were applied to simulate the dynamic adsorption processes of different operation conditions.The results show that

with an increase in temperature

the initial adsorption rate decreased first and then increased

which agreed well with the regularity shown in the pseudo-second order rate constant.The external diffusion resistance reduced with the increasing inlet flow rate.Furthermore

the effective adsorption time might cause the deviation of fitting parameter for pseudo-first order kinetic model.The inlet mercury concentration was beneficial to promoting the mercury adsorption due to the improvement of mass transfer driving force.Result of intra-particle diffusion model shows that the controlling effect of intra-particle diffusion was small.All results in this study were consistent in that the mercury adsorption rate-determining step was given priority to the adsorption of active sites on the surface

external and intra-particle diffusion should be complementary.