期刊
CHEMOSPHERE
卷 202, 期 -, 页码 358-365出版社
PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/j.chemosphere.2018.03.130
关键词
Mercury removal; Mercury speciation; Cycling performance; Manganese oxide
资金
- National Natural Science Foundation of China [51576044, 51676041]
- Postgraduate Research & Practice Innovation Program of Jiangsu Province [KYLX16_0201, CXZZ13_0093, KYLX15_0071]
In this study mercury sorbent based on manganese oxides impregnated gamma-alumina was synthesized. Mercury retention characteristics were investigated by mercury speciation and thermal desorption experiments. No gaseous mercuric oxide was observed in mercury speciation experiments with a mercury mass balance ratio of 89.11%. Maximum mercury desorption peak at 480 degrees C indicated that mercury was adsorbed in the form of mercuric oxide. Three cycles of mercury retention were tested with different thermal treatment in-between to evaluate the cyclic performance. Changes in surface phase and manganese chemistry before and after thermal treatment were characterized by XRD and XPS. Deterioration in mercury retention capacity was observed after thermal desorption at 500 degrees C, which was interpreted with reduced initial adsorption rate calculated by Pseudo-second order kinetic model. XPS studies suggested that atomic ratios of Mn4+/(Mn4++Mn3+) decreased from 73.2% to 32.3% and 33.9% after thermal desorption in N-2 and air, respectively. The reduction of MnO2 to Mn2O3 was irreversible thus the mercury retention capacity could not be restored by thermal desorption at high temperatures. Spent sorbents that were reactivated at 200 degrees C in air without thermal desorption at 500 degrees C possessed considerable cycling performance for mercury retention due to the preserved Mn4+. (C) 2018 Elsevier Ltd. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据