Microwave-assisted synthesis of magnetic Pb(II)-imprinted-poly(schiff base-co-MAA) for selective recognition and extraction of Pb(II) from industrial wastewater

Microwave-assisted magnetic Pb(II)-imprinted-poly(schiff base-co-Methacrylic acid) (MA/Fe3O4@Pb(II)-IIP) was prepared by inverse emulsion-suspension polymerization using lead ion as template ion, methacrylic acid and salicylaldehyde schiff base as bifunctional monomers, ethylene glycol dimethacrylate and azodiisobutyronitrile as cross linker and initiator, respectively. The influence of various single factor on the adsorption effect was analyzed. MA/Fe3O4@Pb(II)-IIP had the best adsorption capacity at 60 mg center dot L-1, pH 6, 303 K and 60 min, and the maximum value was 107.75 mg center dot g(-1). The adsorption mechanism of MA/Fe3O4@Pb(II)-IIP was evaluated by kinetic model and adsorption isotherm. The experimental process could be better fitted by pseudo-second-order kinetics, intra-particle diffusion model and Langmuir adsorption isotherm. Under the optimum SPE conditions of pH 6, 10 ug center dot L-1 Pb(II) solution and 5 mL, 0.5 M eluent, the extraction rates of MA/Fe3O4@Pb(II)-IIP for Pb2+, Cu2+, Cd2+ and Zn2+ were 92.32%, 41.86%, 31.39% and 30.57%, respectively, indicating that it had good reusability and specific recognition. The regeneration and reuse studies revealed that the MA/Fe3O4@Pb(II)-IIP showed no significant decrease in 5 cycles. All these adsorption performance suggested that the proposed polymer had specific recognition ability, high selectivity and high stability. It can be a promising candidate for selective recognition of lead(II) in industrial wastewater.