Mechanism of selective separation on the surface of ionic sieve of removal of lead

This note describes a kind of ionic sieve with high selectivity to remove trace lead in water, in which stannic molybdopyrophosphate is used to be the substrate. The mechanism of selective separation on the surface of ionic sieve of removal of lead was explored by analyzing fourier transformation infrared spectra (FTIR), X-ray photoelectron spectrometry (XPS) and the results of selective adsorptivity experiment. The investigation suggests that in the process of synthesizing ionic sieve the olation reactions occur in solid phase by thermodynamic recrystallization and the adsorption units with special selectivity to lead are formed by chemical modification. After the ion exchange for Pb²⁺, the oaltion reactions not only keep the microstructures of adsorption units from collapse, but also provide lead cavties with special selectivity to lead ion that are capable of having special binding “memory effect” to Pb²⁺ by SnO₃ ²⁻ and P₂O₇ ⁴⁻ groups on the surface of this ionic sieve. Meanwhile, the selective separation capacity is a kind of weak chemical effect that is relative to the valence electron state of the adsorbed ion directly and tightly.