Guerrero Jhonnys D, Arias Eduardo Rada, Gutierrez Laura B
Instituto de Investigaciones en Catálisis y Petroquímica, INCAPE, (FIQ, UNL-CONICET), Santiago del Estero 2829, S3000 Santa Fe, Argentina.
Instituto de Investigaciones en Catálisis y Petroquímica, INCAPE, (FIQ, UNL-CONICET), Santiago del Estero 2829, S3000 Santa Fe, Argentina.
Int J Biol Macromol. 2024 May;266(Pt 2):131110. doi: 10.1016/j.ijbiomac.2024.131110. Epub 2024 Mar 22.
Chitosan (CS) and sodium alginate (SA)-based biocomposites (CSA) were prepared with the in-situ generation of Calcium Carbonate (CSAX_Ca) through a simple, straightforward, economical, and eco-friendly procedure. Different drying conditions (X) were tested to achieve suitable structural and surface characteristics to enhance adsorption capacity: freeze-dried (L), vacuum-dried with methanol (M), and freeze-dried + vacuum-dried with methanol (LM). Temperature and adsorbent dosage effects on the adsorption capacity of Cu or Pb were examined. Results showed that the higher-yielding biocomposite (CSALM_Ca) exhibited rapid adsorption and good diffusion properties, achieving removal above 90 % within contaminant initial concentration ranges of 10-100 mg/L. At 35 °C, a pseudo-second-order kinetic and the Langmuir model effectively described kinetics and isotherms, revealing maximum adsorption (q) of 429 mgCu/L and 1742 mgPb/g. Characterization through FTIR, XRD, and SEM of the as-prepared adsorbents confirmed the presence of CaCO in vaterite and calcite forms and the influence of drying conditions on the material morphology. Post-adsorption material characterization, in combination with adsorption findings, revealed chemisorption processes involving Ca ion exchange for Cu or Pb, resulting in surface-insoluble compounds. The best-performing material showed that after three reuse cycles, the removal of Cu and Pb decreased to 75 % and 62 %, respectively.
通过简单、直接、经济且环保的程序，原位生成碳酸钙（CSAX_Ca）制备了基于壳聚糖（CS）和海藻酸钠（SA）的生物复合材料（CSA）。测试了不同的干燥条件（X），以获得合适的结构和表面特性，从而提高吸附能力：冷冻干燥（L）、用甲醇真空干燥（M）以及冷冻干燥+用甲醇真空干燥（LM）。研究了温度和吸附剂用量对铜或铅吸附能力的影响。结果表明，高产率的生物复合材料（CSALM_Ca）表现出快速吸附和良好的扩散性能，在10-100mg/L的污染物初始浓度范围内，去除率达到90%以上。在35°C下，准二级动力学和朗缪尔模型有效地描述了动力学和等温线，揭示了最大吸附量（q）为429mgCu/L和1742mgPb/g。通过傅里叶变换红外光谱（FTIR）、X射线衍射（XRD）和扫描电子显微镜（SEM）对制备的吸附剂进行表征，证实了球霰石和方解石形式的碳酸钙的存在以及干燥条件对材料形态的影响。吸附后材料的表征与吸附结果相结合，揭示了涉及钙与铜或铅离子交换的化学吸附过程，形成了表面不溶性化合物。性能最佳的材料表明，经过三个重复使用周期后，铜和铅的去除率分别降至75%和62%。
