Department of Environmental Science and Engineering, Xi'an Jiaotong University, Xi'an, People's Republic of China.
Department of Chemistry, College of Resource and Environment, Baoshan University, Baoshan, People's Republic of China.
Environ Technol. 2024 Jan;45(4):681-694. doi: 10.1080/09593330.2022.2119609. Epub 2022 Sep 18.
A kind of adsorbent (Hydrogel-I) derived from sodium alginate and modified alkaline lignin (MAL) has been proved to possess a good adsorption performance for Pb(II)-loaded wastewater based on batch experiments. However, practical removal of Pb(II)-loaded-wastewater is a continuous and dynamic process. Herein, Hydrogel-I was further evaluated by packing it into a fixed-bed column. The breakthrough curves were established under different inflow rates (0.159-0.318 L/min), inflow directions (down-inflow mode and top-inflow mode), initial concentrations (5-20 mg/L) of Pb(II), and bed depths (20-60 cm). The results indicated that the slower inflow rate (0.159 L/min), down-inflow mode, lower initial concentration (5 mg/L), and higher bed depth (60 cm) prolonged breakthrough times () and saturation times (). Compared to the top-inflow mode, the down-inflow mode guaranteed enough contact between Hydrogel-I and Pb(II). The values of adsorption capacity at , and the removal efficiency under the down-inflow mode were higher than that under top-inflow mode by 2.33, 0.78, and 0.07 times, respectively. Hydrogel-I beads exhibited better adsorption performance than other adsorbents by comparing the rate constant () and the adsorption capacity (). The and of Hydrogel-I beads were calculated to be 0.0034 L/(mg·min) and 678 mg/L. Hydrogel-I beads showed good regeneration ability in a three-adsorption-desorption cycle. Meanwhile, FT-IR analysis showed that the groups of -NH/-NH, C=S, and C-S were proved to be the adsorption sites. This study could prove valuable insight into the practical application of Hydrogel-I for dynamic removal of Pb(II) in an inflow-through column.
一种由海藻酸钠和改性碱性木质素（MAL）制备的吸附剂（水凝胶-I）在批量实验中被证明对负载 Pb(II)的废水具有良好的吸附性能。然而，实际去除负载 Pb(II)的废水是一个连续的动态过程。在此，水凝胶-I 通过填充到固定床柱中进一步进行了评估。在不同的流速（0.159-0.318 L/min）、流动方向（下进流模式和上进流模式）、Pb(II)的初始浓度（5-20 mg/L）和床层深度（20-60 cm）下建立了穿透曲线。结果表明，较慢的流速（0.159 L/min）、下进流模式、较低的初始浓度（5 mg/L）和较高的床层深度（60 cm）延长了穿透时间（）和饱和时间（）。与上进流模式相比，下进流模式保证了水凝胶-I 和 Pb(II)之间有足够的接触。在低进流模式下，吸附容量在 、 时的值以及去除效率分别比上进流模式高 2.33、0.78 和 0.07 倍。通过比较速率常数（）和吸附容量（），水凝胶-I 珠粒的吸附性能优于其他吸附剂。水凝胶-I 珠粒的 和 分别计算为 0.0034 L/（mg·min）和 678 mg/L。水凝胶-I 珠粒在三次吸附-解吸循环中表现出良好的再生能力。同时，FT-IR 分析表明，-NH/-NH、C=S 和 C-S 基团被证明是吸附位点。这项研究可以为水凝胶-I 在流入式柱中动态去除 Pb(II)的实际应用提供有价值的见解。
