Abstract: Nanoδ-Bi₂O₃loaded porous zeolite sphere fillers (Bi-PZSF) were synthesized under hydrothermal conditions. Adsorption properties of Bi-PZSF for Cr(VI), including adsorption kinetics, equilibrium capacity and stability, were analyzed. The factors affecting the adsorption, such as dissolved oxygen, pH and competitive anions, and the adsorption mechanism was examined. The adsorption process was well described by the Langmuir model and the pseudosecondorder model. Dissolved oxygen had little effect on adsorption rate under neutral conditions. Adsorption capacity of Cr(VI) was 955.69 mg·kg^-1, which was nearly 120 times higher than that of natural zeolites. Bi-PZSF maintained excellent stability after adsorption and exhibited strong selective absorption of Cr(VI) in NO₃^-and SO₄^2- solutions. The removal rates of Cr(VI) were always above 97%. The removal of Cr(VI) by Bi-PZSF mainly depended on nanoδ-Bi₂O₃ adhering to the sphere, which was achieved by exchanging hydroxyl groups from the surface of δ-Bi₂O₃.

Key words: Great Xing’an Mountains, relative weight., larch caterpillar, meteorological factors, population quantity