Abstract:
In this study, a fibrous activated boron nitride material with abundant pores was prepared. Its specific surface area and mesoporous pore volume were 944.526m
2/g and 0.324cm
3/g, respectively. At the same time, the interaction of Cu
2 、Pb
2 and Cd
2 in wastewater and the adsorption behavior mechanism of activated boron nitride were explored. It was found that in single system, the adsorption capacity of activated boron nitride follows Pb
2 >Cd
2 >Cu
2 , but in ternary system, heavy metal ions will interact, that is, Cu
2 has a synergistic effect on the adsorption of Pb
2 , and has an antagonistic effect on the adsorption of Cd
2 . The adsorption of Pb
2 on Cd
2 has an antagonistic effect within 30 min, and has a synergistic effect after 30 min. On the contrary, Pb
2 has a synergistic effect on the adsorption of Cu
2 , while Cd
2 has an antagonistic effect on the adsorption of Cu
2 , and Cd
2 has a synergistic effect on the adsorption of Pb
2 . Compared with activated carbon, activated boron nitride showed stronger adsorption capacity in heavy metal solution. For heavy metals Cu
2 、Pb
2 and Cd
2 , the maximum adsorption capacity of activated boron nitride was 1.32 times, 24.75 times and 20 times that of activated carbon, respectively. For the adsorption of Cu
2 、Pb
2 and Cd
2 by activated boron nitride, it was found that the adsorption of Cu
2 、Pb
2 and Cd
2 all conformed to the Langmuir model indicating that the adsorption process was mainly controlled by chemical adsorption. XPS was used to analyze the surface chemical state of activated boron nitride after adsorption. It was found that Cu
2 combined with activated boron nitride to Cu(OH)
2 and -OCu, Pb
2 and Cd
2 combine with activated boron nitride to PbCO
3, Cd(OH)
2 and CdCO
3. The adsorption mechanism of activated boron nitride includes three adsorption mechanisms: the formation of complexes between surface-NH
2 and heavy metal ions, the ion exchange between H in -OH and heavy metal ions, and the combination of B-O and heavy metal ions through electrostatic interaction.