XIE Na, ZHANG Jing-yang*, LIU Pei-de

（College of Materials Science and Engineering, Huaqiao University, Xiamen 361021, China）

Abstract: In this paper, the fly ash/bentonite composite particle adsorbent was prepared using raw materials of natural calcium-based bentonite and fuel waste fly ash, and pore-forming agent of industrial starch through the extruding-sphering technology. It was then used to adsorb Pb2+ in wastewater. The effects of different adsorption times, pH values of the solution, its dosages and initial concentrations on its adsorption performance have been studied. It is found that the composite particles prepared by using extruding-sphering method have quite uniform sizes, with no crack on the surface and good mechanical strength. In the adsorption experiment, the adsorption capacity of Pb2+ in solution was 9.74 mg/g, and the removal rate was up to 97.40%, when the dosage of the composite particle adsorbent was 10.0 g/L, the solution pH value was 6, the adsorption time was 120 min, and the initial Pb2+ concentration of the solution was 100 mg/L. The thermodynamic experiments show that the adsorption of Pb2+ by the adsorbent is consistent with the Langmuir adsorption isotherm model.

Keywords: bentonite; fly ash; composite particle adsorbent; Pb2+ adsorption

ACTA MINERALOGICA SINICA Vol. 40, No.1, 2020, page 41-46