U(VI) adsorption by sodium alginate/graphene oxide composite beads in water

Graphene oxide was encapsulated into sodium alginate to prepare SA-GO composite hydrogel for U(VI) adsorption, which characterized by SEM, FTIR, and XPS. The effects of pH, reaction time, initial U(VI) concentration and adsorbent amount on U(VI) adsorption were studied by batch adsorption experiments. The results showed that the maximum adsorption capacity was 149.76 mg/L when pH 5.0, adsorbent 0.1 g/L, 30 °C and initial U(VI) concentration 15 mg/L. The adsorption process accords with pseudo-second-order kinetic models and Langmuir isotherm. After five cycles of desorption and reuse experiments, the adsorption capacity of SA-GO for U(VI) was still higher than 85%.