Tampere University of Technology, Faculty of Natural Sciences, P.O. Box 541, FI-33101 Tampere, Finland; Helmholtz-Zentrum Dresden - Rossendorf, Helmholtz Institute Freiberg for Resource Technology, Bautzner Landstraße 400, 01328 Dresden, Germany.
School of Pharmacy, University of Eastern Finland, P.O. Box 1627, FI-70221 Kuopio, Finland.
Water Res. 2018 Oct 1;142:167-175. doi: 10.1016/j.watres.2018.05.042. Epub 2018 May 24.
This study demonstrated the removal and recovery of uranium(VI) in a fed-batch stirred tank reactor (STR) using waste digested activated sludge (WDAS). The batch adsorption experiments showed that WDAS can adsorb 200 (±9.0) mg of uranium(VI) per g of WDAS. The maximum adsorption of uranium(VI) was achieved even at an acidic initial pH of 2.7 which increased to a pH of 4.0 in the equilibrium state. Desorption of uranium(VI) from WDAS was successfully demonstrated from the release of more than 95% of uranium(VI) using both acidic (0.5 M HCl) and alkaline (1.0 M NaCO) eluents. Due to the fast kinetics of uranium(VI) adsorption onto WDAS, the fed-batch STR was successfully operated at a mixing time of 15 min. Twelve consecutive uranium(VI) adsorption steps with an average adsorption efficiency of 91.5% required only two desorption steps to elute more than 95% of uranium(VI) from WDAS. Uranium(VI) was shown to interact predominantly with the phosphoryl and carboxyl groups of the WDAS, as revealed by in situ infrared spectroscopy and time-resolved laser-induced fluorescence spectroscopy studies. This study provides a proof-of-concept of the use of fed-batch STR process based on WDAS for the removal and recovery of uranium(VI).
本研究采用消化后的活性污泥（WDAS）在分批搅拌槽式反应器（STR）中展示了铀（VI）的去除和回收。批吸附实验表明，WDAS 可以吸附 200（±9.0）mg 的铀（VI）/g 的 WDAS。即使在初始 pH 值为 2.7 的酸性条件下，铀（VI）的最大吸附量也达到了平衡状态，pH 值增加到 4.0。使用酸性（0.5 M HCl）和碱性（1.0 M NaCO）洗脱液，从 WDAS 上成功地证明了铀（VI）的解吸，铀（VI）的释放量超过 95%。由于铀（VI）在 WDAS 上的吸附动力学较快，因此在混合时间为 15 分钟的情况下成功地运行了分批 STR。连续进行了 12 次铀（VI）吸附步骤，平均吸附效率为 91.5%，仅需两次解吸步骤即可从 WDAS 中洗脱超过 95%的铀（VI）。原位红外光谱和时间分辨激光诱导荧光光谱研究表明，铀（VI）主要与 WDAS 的磷酸基和羧基相互作用。本研究提供了基于 WDAS 的分批 STR 工艺用于去除和回收铀（VI）的概念验证。
