Heavy metal ion wastewater poses a serious threat to human health and the environment. The adsorption method is an important method to remove heavy metal ions from heavy metal wastewater. Magnetic attapulgite (ATP) composite nanomaterials with excellent adsorption properties were prepared by grafting the Fe3O4 nanoparticles and using 3-aminopropyl triethoxy silane (APTES) modification. The prepared ATP-Fe3O4-APTES materials were used as adsorbents and applied to the treatment of heavy metal ion wastewater. The structure and surface properties of the materials were characterized by FT-IR, XRD, SEM, TEM, and BET characterization, Zeta potential, and VSM. The effects of pH, adsorption time, adsorption temperature, and initial concentration of Pb2+ on the adsorption properties of the ATP-Fe3O4-PEI materials were investigated. The results show that the maximum adsorption capacity of the materials for Pb2+ was 129.32 mg·g-1 under optimum conditions. The adsorption process conformed to the pseudo second order kinetic model and Langmuir adsorption isotherm, which indicates that the adsorption of Pb2+ is a monolayer chemical adsorption and a spontaneous endothermic process. The driving force of adsorption mainly comes from the coordination between the amino group (-NH2) on the ATP-Fe3O4-APTES surface and Pb2+. These results indicate that the functionalized magnetic attapulgite adsorbent has good adsorption properties for heavy metal ions and is expected to be used in the treatment of heavy metal ion wastewater.
Keywords: 3-aminopropyltriethoxy silane (APTES); Fe3O4; Pb2+; adsorption; attapulgite; heavy metal ions wastewater.