Students Innovation and Entrepreneurship Center, Enrollment and Employment Department, Sichuan Agricultural University, Chengdu, 611130, China; College of Civil Engineering, Sichuan Agricultural University, Chengdu, 611830, China.
College of Civil Engineering, Sichuan Agricultural University, Chengdu, 611830, China.
J Environ Manage. 2023 Apr 1;331:117283. doi: 10.1016/j.jenvman.2023.117283. Epub 2023 Jan 24.
For improving inadequate nanostructural stability and promote algal removal efficiency, a novel nanochitosan-grafted flocculant (PAD-g-MNC) with an enhanced branched nanostructure and high molecular weight (MW) was fabricated via maleic anhydride acylation polymerization. Characterization results verified the successful synthesis of the flocculant and the formation of an irregular particle nanostructure. PAD-g-MNC exhibited superior algal and extracellular organic matter (EOM) removal and obtained the turbidity and chlorophyll-a removal rates of 93.46%-95.39% and 95.10%-97.31%, respectively, at the dosage of 4-5 mg L. The growth rate, strength factor, and recovery factor of algal flocs flocculated by PAD-g-MNC were 90.36, 0.63, and 0.27 (100 rpm), respectively, and were higher than other flocculants prepared through conventional methods. Results indicated that the high intrinsic viscosity and stability branched nanostructure promoted the formation of stable flocs and regeneration ability of flocs. MW distribution and three-dimensional fluorescence analyses revealed that the special structure of PAD-g-MNC was beneficial to the removal of tryptophan-like proteins in EOM. Strong adsorption-adhesion and bridging-netting effects of the nanostructure chain were the dominated mechanisms in the improvement of flocculation efficiency. This study provided theoretical and experimental guidance for the design of flocculants with superior performance and efficient algal water purification performance.
为了提高纳米结构的稳定性并增强藻类去除效率，通过马来酸酐酰化聚合，制备了一种具有增强的支化纳米结构和高分子量（MW）的新型壳聚糖接枝絮凝剂（PAD-g-MNC）。表征结果验证了絮凝剂的成功合成以及不规则颗粒纳米结构的形成。在投加量为 4-5mg/L 时，PAD-g-MNC 对藻类和胞外有机物（EOM）表现出优异的去除效果，浊度去除率和叶绿素-a 去除率分别达到 93.46%-95.39%和 95.10%-97.31%。用 PAD-g-MNC 絮凝的藻类的增长率、强度因子和恢复因子分别为 90.36、0.63 和 0.27（100rpm），均高于通过常规方法制备的其他絮凝剂。结果表明，高固有粘度和稳定的支化纳米结构促进了稳定絮体的形成和絮体的再生能力。MW 分布和三维荧光分析表明，PAD-g-MNC 的特殊结构有利于去除 EOM 中的色氨酸样蛋白。纳米结构链的强吸附-黏附作用和架桥网捕作用是提高絮凝效率的主要机制。本研究为设计具有优异性能和高效藻类水净化性能的絮凝剂提供了理论和实验指导。
