Enhancing Pb2+ removal efficiency in flow-through systems using flue gas desulfurization gypsum-based porous materials: Experimental and numerical studies

Abstract

This study addresses the poor permeability of flue gas desulfurization (FGD) gypsum in water remediation and further explores its potential for resource utilization. FGD gypsum-based porous materials (FGPMs) were prepared using different foaming behavior as permeable reactive barrier (PRB) media materials. The dynamic removal performance of Pb2+ was investigated, and a numerical model was developed to validate the results. The findings reveal that the adsorption mechanisms of FGPMs primarily involve ion exchange and surface precipitation. Pb2+ does not alter the structure or functional groups of the materials. By optimizing the foaming behavior to enhance pore connectivity, the adsorption capacity increased from 8.78 mg/g to 13.42 mg/g, thereby extending the service life of the PRB. The presence of closed and capillary pores hinders the dynamic removal performance of Pb2+. Furthermore, the FGPMs exhibit superior removal performance at low flow rates, low concentrations, and high column heights, as confirmed by the numerical model. These results offer valuable insights for designing and optimizing FGD gypsum-based adsorption processes to remove Pb2+ from wastewater efficiently.