State Key Joint Laboratory of Environment Simulation and Pollution Control (SKJLESPC), Beijing Key Laboratory of Emerging Organic Contaminants Control (BKLEOCC), School of Environment, Tsinghua University, Beijing 100084, China.
Green Intelligence Environmental School, Yangtze Normal University, Chongqing 408100, China.
Int J Biol Macromol. 2020 Apr 1;148:543-549. doi: 10.1016/j.ijbiomac.2020.01.171. Epub 2020 Jan 18.
In the present work, chitosan physicochemical transformations that occur during high energy ball milling are investigated and correlated with adsorption capacity of organic pollutants (using azo-dye reactive red 2 as molecular probe). Experimental results reveal that chitosan ball milled for 1 h shows a 70% increase of adsorption capacity, compared to unmilled one, while longer milling time causes a sensible reduction of such capacity. This trend correlates with specific surface area evolution under milling, thus suggesting the primary role of particle comminution in augmenting chitosan adsorption properties. Amorphization of particle surface was found to be marginally relevant for adsorption capacity enhancement. Maximum adsorption capacity (estimated by isothermal equilibrium study) and adsorption rate are augmented by ball milling, with an optimal value found at 1 h milling. Finally, the milled materials were tested to adsorb perfluorooctane sulfonate, obtaining 1.54 mmol g uptake with 1 h milled chitosan. This suggests that chitosan could be used as a cheap expendable material to remove those pollutants, like perfluorooctane sulfonate and the other perfluoroalkyl substances, that deserves destruction and cannot be removed by conventional degradation technologies.
在本工作中，研究了高能球磨过程中壳聚糖的物理化学变化，并将其与有机污染物的吸附能力相关联（使用偶氮染料活性红 2 作为分子探针）。实验结果表明，与未球磨的壳聚糖相比，球磨 1 小时的壳聚糖的吸附能力增加了 70%，而更长的球磨时间会导致这种能力的明显降低。这种趋势与球磨过程中比表面积的演变相关，因此表明颗粒细化在增强壳聚糖吸附性能方面起着主要作用。发现颗粒表面的非晶化对吸附能力的增强作用不大。通过球磨，最大吸附容量（通过等温平衡研究估计）和吸附速率得到提高，在 1 小时球磨时达到最佳值。最后，对研磨材料进行了测试，以吸附全氟辛烷磺酸，用 1 小时研磨的壳聚糖获得了 1.54 mmol g 的吸附量。这表明壳聚糖可以用作廉价的一次性材料，用于去除那些需要销毁且不能通过传统降解技术去除的污染物，如全氟辛烷磺酸和其他全氟烷基物质。
