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[Display omitted] Fabricating a high-performance adsorbent as a desirable candidate for removing Pb2+ from aqueous water remains a challenge. Aramid nanofibers (ANFs) are promising building blocks that have realized multifunctional applications due to their intrinsic mechanical and chemical stability. Herein, an in situ loading strategy for preparing nanofiber composite aerogel was proposed by assembling ANFs into a 3D aerogel and applying it as host media for the in situ polymerization of pyrrole followed by facile redox reaction between the polypyrrole (PPy) and MnO 4 –1 to load manganese dioxide (MnO 2). The idea was to fully exploit the structural advantages of ultra-low bulk density, large specific surface area, and high porosity of ANFs, and the possible chemical adsorption characteristics of MnO 2 on the basis of ion exchange reaction. The adsorption capacity of 3D ANF/MnO 2 composite aerogel was as large as 554.36 mg/g for Pb2+. The adsorption mechanism based on an exchange reaction between Pb2+ and protons on the surface of MnO 2 was also investigated. The desorption results showed that the adsorption performance could remain up to 90% after five times of usage. In conclusion, this research provides promising insights into the preparation of high-performance lead adsorbent for water treatment. [ABSTRACT FROM AUTHOR]

[Display omitted] • ZIF-67 was in situ assembled onto ANF aerogel to get 3D monolith adsorbent. • ANF/ZIF-67 aerogel showed stable and competitive structural features. • ANF/ZIF-67 aerogel demonstrated high adsorption capacity for Cu2+ and Cr6+. • ANF/ZIF-67 aerogel displayed excellent adsorption capacity for CV and MO. • The adsorption capacity maintained up to 80% after five times of usage. The fabrication of a high-efficiency adsorbent, as a promising candidate for removing metal ions and organic dyes from aqueous solution, is a research hotspot but remains challenging. Aramid nanofibers (ANFs) are emerging building blocks that have realized multifunctional applications in various fields because of their intrinsic mechanical and chemical stability. In this research, three-dimensional (3D) ANF aerogel was assembled and applied in for in situ assembly of zeolitic imidazole framework-67 (ZIF-67). The aim, was to fully exploit the structural advantages of this composite's ultra-low bulk density, large specific surface area, and high porosity, as well as provide more available adsorption sites by ZIF-67 polyhedrons, to facilitate pollutant adsorption from waste water. The prepared 3D ANF/ZIF-67 composite aerogel possessed favorable adsorption performance for heavy metal ions (250.95 and 183.29 mg/g for Cu2+ and Cr6+, respectively) and organic dyes (199.36 and 65.98 mg/g for CV and MO, respectively), greatly exceeding that of the corresponding 3D ANF aerogel. Desorption experiments further demonstrated that up to 80% adsorption performance for heavy metal ions and organic dyes could be maintained after five times of usage. Hence, this research can provide new insights into the preparation of highly efficient adsorbents for water treatment. [ABSTRACT FROM AUTHOR]