Abstract:Flyash-slag based polyporous geopolymers (FSPGs) were prepared by changing the dosage of foaming agent with fly ash and slag as the main raw materials, H2O2 as the foaming agent. XRD, CT scanning, and BET analysis were used to characterize the phase composition and pore structure characteristics of the sample, and to investigate the effect of H2O2 dosage on the pore structure parameters and mechanical properties of the materials. Meanwhile, the adsorption effect of FSPGs on Pb(Ⅱ) was studied through static adsorption experiments. The results show that when the foaming agent dosage is 4%, the FSPGs have a high porosity and pore connectivity, large pore size, uniform pore distribution and compressive strength of 1.20 MPa. BET analysis shows that it has a typical mesoporous structure with average pore size of 8.88 nm, BET surface area of 9.74 m2/g, and pore volume of 0.024 cm3/g. It has a good adsorption effect on Pb(Ⅱ) and the adsorption process conforms to the quasi-secondary kinetic model. Based on FTIR and XPS analysis, it is believed that Pb(Ⅱ) binds to FSPGs in the forms of M-O-T and M-O, thereby achieving efficient adsorption of Pb(Ⅱ).