Synthesis and characterization of amino-grafted attapulgite/graphene oxide nanocomposites and their adsorption for Pb(II) removal

Heavy metal ions have become a major problem that seriously affects the environment, ecology, and human health with the development of industrialization. Herein, the amino-grafted attapulgite/graphene oxide (A-ATP/GO) nanocomposites were synthesized for Pb(II) removal. The influencing factors including the ratio of the components, pH value, adsorption time, initial concentration of Pb(II) solution, and adsorbent amount were investigated to achieve the optimal adsorption performance. The as-prepared A-ATP/GO were used in Pb(II) solution (150 mg/L, 30 mL, pH = 5) for Pb(II) adsorption, which exhibited a great adsorption ability of 146.97 mg/g for Pb(II). The adsorption kinetic model and isotherms model were applied to investigate the adsorption mechanism of Pb(II) on A-ATP/GO. The A-ATP/GO composite could still maintain an original adsorption of 79.85% after 5 consecutive times, exhibiting the good reproducibility. It was believed that our results could shed light on the design and fabrication of low-cost graphene-based composite adsorbents for high-efficient Pb(II) removal.