Oyarce Estefanía, Xiao Ling-Ping, Sun Run-Cang, Sánchez Julio
Department of Metallurgical Engineering, Faculty of Engineering, University of Santiago de Chile, Santiago, Chile.
Liaoning Key Lab of Lignocellulose Chemistry and BioMaterials, Liaoning Collaborative Innovation Center for Lignocellulosic Biorefinery, College of Light Industry and Chemical Engineering, Dalian Polytechnic University, Dalian 116034, China.
Int J Biol Macromol. 2025 Sep;323(Pt 1):147010. doi: 10.1016/j.ijbiomac.2025.147010. Epub 2025 Aug 20.
This study focuses on the preparation of bio-based adsorbents composed of carboxylated lignin (LC) and potassium polyacrylate (PAS) to remove Mg from aqueous solutions in the presence of Li. The successful incorporation of carboxylate groups into lignin was achieved, which was corroborated by FT-IR. Acid-base titration allowed the quantification of 11.7 ± 0.016 mmol of -COO groups per gram of LC. Radical polymerization was used to obtain the bio-based adsorbents. The structural composition was corroborated by FT-IR and their porous morphology was evaluated by SEM and BET isotherms. The incorporation of LC improved the adsorption capacity of the material for Mg, increasing it by 60 %. The adsorption process was more accurately described by the PFO and Redlich Peterson kinetic models. The effective adsorption and the ion-exchange adsorption mechanism of Mg on the adsorbents were confirmed by XPS, FT-IR, and SEM/EDS analyses. Furthermore, the adsorbent systems were shown to be able to adsorb Mg in the presence of Li, reducing the concentration ratio from 8:1 to 6:1. However, Mg ions showed higher affinity for PAS-20 %-LC adsorbents (α = 3.78) as compared to PAS adsorbents (α = 0.50), confirming that the incorporation of LC into the adsorbent enhances Mg adsorption. A preferential affinity toward divalent ions was observed in multicomponent solutions after the adsorption process. The Mg adsorption capacity on PAS-20 %-LC remained almost constant even with increasing ionic strength of the system.
本研究聚焦于制备由羧化木质素（LC）和聚丙烯酸钾（PAS）组成的生物基吸附剂，以在锂存在的情况下从水溶液中去除镁。通过傅里叶变换红外光谱（FT - IR）证实了羧基成功引入木质素中。酸碱滴定法可定量测定每克LC中含11.7±0.016 mmol的 - COO基团。采用自由基聚合反应制备生物基吸附剂。通过FT - IR对其结构组成进行了证实，并通过扫描电子显微镜（SEM）和BET等温线对其多孔形态进行了评估。LC的引入提高了材料对镁的吸附容量，使其增加了60%。采用PFO和Redlich Peterson动力学模型能更准确地描述吸附过程。通过X射线光电子能谱（XPS）、FT - IR和SEM/能谱分析（EDS）证实了镁在吸附剂上的有效吸附和离子交换吸附机制。此外，研究表明吸附剂体系在锂存在的情况下能够吸附镁，将浓度比从8:1降低到6:1。然而，与PAS吸附剂（α = 0.50）相比，镁离子对PAS - 20% - LC吸附剂表现出更高的亲和力（α = 3.78），这证实了在吸附剂中引入LC可增强镁的吸附。吸附过程后，在多组分溶液中观察到对二价离子的优先亲和力。即使体系离子强度增加，PAS - 20% - LC对镁的吸附容量几乎保持不变。
