▎ 摘　　要

First fabrication of microorganism-graphene oxide composites for Uranium(VI) adsorption from aqueous solutions was performed via immobilized Lysinibacillus sp. on graphene oxide (GO). Lysinibacillus-GO was characterized using scanning electron microscopy and Fourier transform infrared spectroscopy. The influence of contact time, pH values, U(VI) initial concentration, as well as the adsorption kinetics and isotherm of U(VI) in aqueous solution were estimated through batch adsorption experiments. Results revealed that Lysinibacillus-GO exhibited superior U(VI) removal ability, and its maximum adsorption capacity for U(VI) from aqueous solution was 149.3 mg/g. Furthermore, the pseudo-second order kinetic and Langmuir isotherm model matched well with this adsorption process according to the adsorption kinetic and isotherm study, suggesting that monolayer coverage of U(VI) adsorption occurred on the Lysinibacillus-GO surface and that chemisorption was the main limiting step for controlling adsorption rate. The adsorption mechanism of U(VI) by Lysinibacillus-GO adsorbent was mainly ascribed to an inner-sphere complexation between U(VI) and oxygen-containing groups. Regeneration study demonstrated that Lysinibacillus-GO can be used as a regenerated adsorbent for capturing U(VI) from aqueous solutions. This study provides new insights in taking full advantage of adsorption feature of GO and ubiquitous microbial resources and their use in remediating uranium-polluted aqueous environments. (C) 2019 Elsevier Ltd. All rights reserved.