Rapid removal of uranium(VI) using functionalized luffa rattan biochar from aqueous solution

Due to its reliable performance and low manufacturing cost, biochar has gradually attracted attention in the treatment of uranium-containing wastewater. Herein, Luffa rattan (LR), a biowaste material, was used to synthesize functional biochar (F-LRBC) to adsorb U(VI) from aqueous solutions for the first time. The effect of solution pH, contact time and initial concentration of uranyl ions on uranium(VI) adsorption by F-LRBC was evaluated. FT-IR and SEM analysis confirmed that there are abundant oxygen-containing functional groups and pores on the surface of F-LRBC. Experiments demonstrated that the adsorption behavior of uranium(VI) by F-LRBC is spontaneous and efficient. The maximum adsorption capacity of F-LRBC for uranyl ions predicted by the Langmuir model was higher than that of most biochar adsorbent. The adsorption mechanism of uranyl ions on F-LRBC is complicated, including electrostatic interaction, complexation and physical adsorption.