Ecole des mines d'Alès, Centre des Matériaux des Mines d'Alès, Pôle Matériaux Polymères Avancés, 6 avenue de Clavières, F-30319 Alès cedex, France.
Nuclear Materials Authority, 530 El-Maadi, Cairo, Egypt.
J Colloid Interface Sci. 2017 Oct 15;504:780-789. doi: 10.1016/j.jcis.2017.06.028. Epub 2017 Jun 8.
Algal (Laminaria digitata) beads and algal foams have been prepared by a new synthesis mode and the sorbents were tested for praseodymium sorption in batch and fixed-bed like systems (recirculation or one-pass modes), respectively. Metal binding occurs through ion-exchange with Ca(II) ions used for ionotropic gelation of alginate contained in the algal biomass and eventually with protons. Sorption isotherms at pH 4 are described by the Langmuir and the Sips equations with maximum sorption capacities close to 110-120mgPrg. Uptake kinetics are fitted by the pseudo-second order reaction rate equation for both beads and foams; in the case of beads the Crank equation also gives good fit of experimental data. Metal is successfully desorbed using 2M HCl/0.05M CaCl solutions and the sorbent can be efficiently re-used for a minimum of 5 cycles with negligible decrease in sorption/desorption properties and appreciable concentrating effect (around 8-10 times the initial metal concentration). Tested in continuous mode, the algal foam shows typical breakthrough curves that are fitted by the Yan method; desorption is also efficient and allows under the best conditions to achieve a concentration factor close to 8.
通过一种新的合成模式制备了海藻（海带）珠和海藻泡沫，并用批式和固定床类似系统（循环或单一流模式）分别测试了它们对镨的吸附。金属结合是通过与海藻生物质中所含藻酸盐的离子型凝胶化所用的 Ca(II) 离子以及最终与质子的离子交换发生的。在 pH 4 下，吸附等温线由 Langmuir 和 Sips 方程描述，最大吸附容量接近 110-120mgPrg。珠和泡沫的吸附动力学均符合准二级反应速率方程；对于珠，Crank 方程也能很好地拟合实验数据。使用 2M HCl/0.05M CaCl 溶液可成功解吸金属，并且该吸附剂可在至少 5 个循环中有效重复使用，吸附/解吸性能几乎没有下降，并且具有明显的浓缩效果（约为初始金属浓度的 8-10 倍）。在连续模式下进行测试时，海藻泡沫显示出典型的穿透曲线，可通过 Yan 方法进行拟合；解吸也很有效，在最佳条件下可达到接近 8 的浓缩因子。
