Research on the adsorption of melamine for Cu(II) and Pb(II)

Abstract Melamine contains three aromatic nitrogen atoms and three free amino groups, which have great adsorption potential for heavy metallic ions in wastewater. The sorption performances of melamine for Cu(II) and Pb(II) ( They are denoted as Cu&Pb) were studied. Some major effects such as adsorption time, original concentration, and temperature on its adsorption performances were studied. The effects confirmed that melamine had true adsorption for Cu&Pb, and higher selectivity for the adsorption of Cu&Pb in a binary blended system. The adsorption amount of Pb(II) on melamine reached 4.91 mg/g at pH 5, adsorption equilibrium time of 12 h, and temperature of 55 °C, while the sorption amount of Cu(II) was only 2.70 mg/g, with a difference of about 1.8 times. The adsorption mechanism shows that the sorption of Cu&Pb on melamine follows the Lagergren quasi-second-order kinetic model. This result indicates that the mixture of Cu&Pb can be separated by stepwise processes from a binary mixed system.