Faculty of Nuclear Engineering, Shahid Beheshti University, Tehran, Iran.
J Hazard Mater. 2011 May 15;189(1-2):141-9. doi: 10.1016/j.jhazmat.2011.02.011. Epub 2011 Mar 3.
Uranium(VI) biosorption from aqueous solutions containing 60 mg l(-1) metal concentration by Ca-pretreated Cystoseira indica alga was studied in a packed bed column with 1.5 cm internal diameter. The effect of bed height and flow rate on biosorption process was investigated and the experimental breakthrough curves were obtained. Results showed that by increasing the bed height, the breakthrough and exhaustion times increased and the slope of breakthrough curves decreased. Also, it was observed that the controlled-rate step shifted from external to internal mass transfer limitations, as the flow rate increased. The maximum uptake capacity, 318.15 mg g(-1), and total metal removal, 59.32%, were obtained at flow rate of 2.3 ml min(-1) and bed height of 6 cm. The column was regenerated using 0.1M HCl solution and sorption-desorption studies were carried out for three cycles. The obtained results confirmed that reusability of this biosorbent is possible. The results obtained agreed well with the bed depth service time model. In addition, for estimations of the parameters necessary for the design of a large-scale packed bed column, the experimental data were also fitted to the Thomas, Yan and Belter models and were found to agree with the experimental data fairly well.
用预处理的半叶马尾藻（Cystoseira indica alga）从含 60mg/L 金属浓度的水溶液中吸附铀（VI），在 1.5cm 内径的填充床柱中进行了研究。考察了床层高度和流速对吸附过程的影响，并得到了实验穿透曲线。结果表明，随着床层高度的增加，穿透和耗尽时间增加，穿透曲线的斜率降低。此外，随着流速的增加，观察到控制速率步骤从外部传质限制转移到内部传质限制。在流速为 2.3ml/min 和床层高度为 6cm 时，最大吸附容量为 318.15mg/g，总金属去除率为 59.32%。用 0.1M HCl 溶液再生柱，并进行了三个周期的吸附-解吸研究。得到的结果证实了这种生物吸附剂的可重复使用性。所得结果与床层深度时间模型吻合较好。此外，为了估计设计大型填充床柱所需的参数，还将实验数据拟合到托马斯（Thomas）、严（Yan）和贝尔特（Belter）模型中，发现它们与实验数据相当吻合。
