Zhang Zhaohui, Chen Yehong, Wu Chaojun
Key Laboratory of Pulp and Paper Science & Technology of Ministry of Education, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China.
State Key Laboratory of Biobased Material and Green Papermaking, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China.
Polymers (Basel). 2022 Jul 11;14(14):2824. doi: 10.3390/polym14142824.
With the continuous research on lignin-based sorbents, there are still limitations in the research of spherical sorbents with a high adsorption capacity for Pb2+. In order to solve the problem of low adsorption effect, alkali lignin (AL) was modified and assembled to increase the adsorption active sites. In this work, we used dual-modified lignin (DML) as a raw material to assemble a singular lignin-based multilayer microsphere (LMM) with sodium alginate (SA) and dopamine. The prepared adsorbent had various active functional groups and spherical structures; the specific surface area was 2.14 m2/g and the average pore size was 8.32 nm. The adsorption process followed the Freundlich isotherm and the second-order kinetic model. Therefore, the LMM adsorbed Pb2+ ascribed by the electrostatic attraction and surface complexation; the adsorption capacity was 250 mg/g. The LMM showed a selective adsorption performance for Pb2+ and the adsorption capacity followed the order Pb2+ (187.4 mg/g) > Cu2+(168.0 mg/g) > Mn2+(166.5 mg/g). After three cycles, the removal efficiency of Pb2+ by the LMM was 69.34%, indicating the reproducibility of LMM.
随着对木质素基吸附剂研究的不断深入，对Pb2+具有高吸附容量的球形吸附剂的研究仍存在局限性。为了解决吸附效果低的问题，对碱木质素（AL）进行改性和组装以增加吸附活性位点。在这项工作中，我们以双改性木质素（DML）为原料，与海藻酸钠（SA）和多巴胺组装成单一的木质素基多层微球（LMM）。制备的吸附剂具有多种活性官能团和球形结构；比表面积为2.14 m2/g，平均孔径为8.32 nm。吸附过程遵循Freundlich等温线和二级动力学模型。因此，LMM对Pb2+的吸附归因于静电吸引和表面络合作用；吸附容量为250 mg/g。LMM对Pb2+表现出选择性吸附性能，吸附容量顺序为Pb2+（187.4 mg/g）>Cu2+（168.0 mg/g）>Mn2+（166.5 mg/g）。经过三个循环后，LMM对Pb2+的去除效率为69.34%，表明LMM具有可重复性。
