Environmental Engineering and Earth Sciences, Clemson University, Anderson, SC 29625, USA; Sustainable Gas Institute, Imperial College London, London SW7 1NA, UK.
Environmental Engineering and Earth Sciences, Clemson University, Anderson, SC 29625, USA.
Sci Total Environ. 2021 Nov 1;793:148473. doi: 10.1016/j.scitotenv.2021.148473. Epub 2021 Jun 16.
The purpose of this study is to investigate adsorptive removal of carbamazepine from natural source waters by superfine pulverized powdered activated carbon. Superfine pulverization is becoming an increasingly attractive approach to decrease the diffusion path of a target adsorbate molecule and improve the overall the kinetics of activated carbon adsorption. Here we report the impact of pulverization on powdered activated carbon characteristics, and carbamazepine adsorption behavior in distilled and deionized water and natural organic matter solutions. The superfine pulverization decreased the particle size of activated carbon by 50 folds and the specific surface area by 24%. In addition, the micropore volume of the activated carbon decreased from 0.23 cm/g to 0.14 cm/g, while mesopore and macropore volumes increased from 0.15 cm/g and 0.11 cm/g to 0.18 cm/g and 0.48 cm/g, respectively. In terms of surface chemistry, the oxygen and iron contents of the activated carbon increased notably after pulverization. Despite the decrease in surface area and increase in surface polarity, the pulverization improved the adsorption kinetics especially for short contact times i.e., < 6-h. In general, the dissolved organic carbon concentration negatively influenced the kinetic advantage of superfine pulverized activated carbon. Isotherm results indicated that the parent adsorbent has a higher adsorption capacity than superfine activated carbon in distilled and deionized water and in natural waters. This was attributed to the losses in specific surface area and favorable sorption sites inside micropores. Our literature analysis indicated that unlike the small molecular weight hydrophilic organic compounds, the pseudo-equilibrium adsorption capacity could be increased or at least not deteriorated for hydrophobic molecules (K > 3). Therefore, superfine pulverization of PAC can serve as a promising approach to remove micropollutants from natural source waters with a kinetic advantage.
本研究旨在探讨超细粉碎粉末状活性炭对天然水源中卡马西平的吸附去除作用。超细粉碎正成为一种极具吸引力的方法，可以缩短目标吸附物分子的扩散路径，提高活性炭吸附的整体动力学性能。本文报道了粉碎对粉末状活性炭特性以及在去离子水和天然有机物溶液中卡马西平吸附行为的影响。超细粉碎使活性炭的粒径减小了 50 倍，比表面积减小了 24%。此外，活性炭的微孔体积从 0.23cm³/g 减小到 0.14cm³/g，而中孔和大孔体积则分别从 0.15cm³/g 和 0.11cm³/g 增加到 0.18cm³/g 和 0.48cm³/g。就表面化学而言，粉碎后活性炭的氧和铁含量明显增加。尽管比表面积减小，表面极性增加，但粉碎仍改善了吸附动力学，特别是在短接触时间（<6 小时）内。一般而言，溶解有机碳浓度会对超细粉碎活性炭的动力学优势产生负面影响。等温线结果表明，在去离子水和天然水中，母体吸附剂的吸附容量高于超细活性炭。这归因于比表面积的损失和微孔内有利的吸附位损失。我们的文献分析表明，与小分子亲水性有机化合物不同，对于疏水分子（K>3），假平衡吸附容量可以增加或至少不会恶化。因此，PAC 的超细粉碎可以作为一种很有前途的方法，用于从天然水源中去除微量污染物，并具有动力学优势。
