Grafted PVDF Particles for Efficient Removal of Trace Lead (II) Ions in Aqueous Solution

To improve the water quality, a new type of grafted poly(vinylidene fluoride) (PVDF) particles was designed and synthesized to adsorb trace Pb2+ in water. Through the surface hydroxylation of PVDF particles, followed by the sequential coupling of gelatin, β-cyclodextrin (β-CD) and acrylic acid (AA) provide grafted PVDF particles (PAGCA) with multi-functionalized groups. The newly prepared PAGCA particles were characterized by FT-IR, XPS, and SEM. The results show that the PAGCA particles have excellent adsorption performance for Pb(II) in water and can remove Pb(II) rapidly and thoroughly with a removal rate of 100%. The adsorption capacity of PAGCA particles increased with the increase of solid–liquid ratio or pH value. The good adsorption performance of PAGCA particles was also demonstrated by completely removing 2.37 μg/L of Pb(II) from a river water sample. XPS and SEM analysis further confirmed the formation and adsorption of Pb(II) on the surface of PAGCA particles. The synthesized PAGCA particles also show good adsorption ability to cadmium(II) with a removal rate of 93.6% in single ionic water and 87.9% in river water, respectively. It is concluded that the combination of hydroxyl group, carboxyl group, and amino group on the surface of the new grafted PVDF particles greatly improves the adsorption capacity of PVDF particles for Pb2+, and it has a good application prospect in the removal of trace Pb(II) in water.