School of Environmental Engineering, Jiangsu Key Laboratory of Industrial Pollution Control and Resource Reuse, Xuzhou University of Technology, Xuzhou 221018, China; Jiangsu Key Laboratory of Vehicle Emissions Control, Center of Modern Analysis, Nanjing University, Nanjing 210093, China; Department of Agricultural and Biological Engineering, University of Florida, Gainesville, FL 32611, USA; Jiangsu Key Laboratory of Environmental Material and Environmental Engineering, Yangzhou University, Yangzhou 225009, China.
Department of Agricultural and Biological Engineering, University of Florida, Gainesville, FL 32611, USA.
Chemosphere. 2019 Mar;218:680-686. doi: 10.1016/j.chemosphere.2018.11.144. Epub 2018 Nov 23.
Hydrochars derived from hickory wood and peanut hull through hydrothermal carbonization were activated with HPO and KOH to improve their performance as a volatile organic compound (VOC) adsorbent. Polar acetone and nonpolar cyclohexane were used as representative VOCs. The VOC adsorptive capacities of the activated hydrochars (50.57-159.66 mg⋅g) were greater than that of the nonactivated hydrochars (15.98-25.36 mg⋅g), which was mainly caused by the enlargement of surface area. The significant linear correlation (R = 0.984 on acetone, and R = 0.869 on cyclohexane) between BET surface areas of hydrochars and their VOC adsorption capacities, together with the obvious adsorption exothermal peak of differential scanning calorimetry curve confirmed physical adsorption as the dominating mechanism. Finally, the reusability of activated hydrochar was tested on HPO activated hickory hydrochar (HHP), which had higher acetone and cyclohexane adsorption capacities. After five continuous adsorption desorption cycles, the adsorptive capacities of acetone and cyclohexane on HHP decreased by 6.2% and 7.8%, respectively. The slight decline in adsorption capacity confirmed the reusability of activated hydrochar as a VOC sorbent.
通过水热碳化法从山核桃木和花生壳中得到的水炭，经 HPO 和 KOH 活化后，可作为挥发性有机化合物（VOC）吸附剂，提高其性能。选用极性的丙酮和非极性的环己烷作为代表性的 VOC。与非活化水炭（15.98-25.36 mg·g）相比，活化水炭（50.57-159.66 mg·g）的 VOC 吸附容量更大，这主要是由于比表面积的增大。水炭的 BET 比表面积与其 VOC 吸附容量之间存在显著的线性相关性（丙酮为 R=0.984，环己烷为 R=0.869），同时差示扫描量热法曲线的明显吸附放热峰证实了物理吸附是主要的吸附机制。最后，对具有较高丙酮和环己烷吸附容量的 HPO 活化山核桃水炭（HHP）进行了活化水炭的可重复使用性测试。在五个连续的吸附-解吸循环后，HHP 对丙酮和环己烷的吸附容量分别下降了 6.2%和 7.8%。吸附容量的轻微下降证实了活化水炭作为 VOC 吸附剂的可重复使用性。
