Incorporation of phytic acid into reed straw-derived hydrochar for highly efficient and selective adsorption of uranium(VI)

An innovative phytic acid modified reed straw-derived hydrochar composite (PA-C-RBC) was prepared by using inexpensive reed straw and non-toxic phytic acid for the removal of uranium(VI) from aqueous environment. Several characterization results showed that PA-C-RBC was rough and porous with a large number of hydroxyl, carboxyl, and phosphate groups. The uranium(VI) adsorption process by PA-C-RBC conformed to pseudo-second-order kinetic and Langmuir models, and the theoretical maximal adsorption capacity could attain 418.78 mg/g at pH 5.0. PA-C-RBC had 72.66 % of selectivity and 6772.99 mL/g of distribution coefficient for U(VI). Due to the strong chelating between the hydroxyl and phosphate groups on PA-C-RBC and U(VI), PA-C-RBC had excellent adsorption selectivity. These finding highlighted a high potential for removing U(VI) from aqueous solutions.