School of Environment and Civil Engineering, Jiangnan University, Wuxi 214122, PR China.
School of Environment and Civil Engineering, Jiangnan University, Wuxi 214122, PR China.
J Hazard Mater. 2021 Apr 5;407:124381. doi: 10.1016/j.jhazmat.2020.124381. Epub 2020 Nov 2.
Conversion of gaseous elemental mercury (Hg) to particulate-bound mercury (Hg) by the injection of disposable sorbents or to gaseous oxidized mercury (Hg) by catalysts is not suitable to control Hg emissions from power plants burning Hg-rich coal because removed Hg may be released as secondary pollution, particularly during the employment of fly ash and desulfurization gypsum. In this study, sulfureted phosphotungstic acid modified γ-FeO (HPW/γ-FeO) was employed as a magnetic and reproducible sorbent to recover gaseous Hg in coal-fired flue gas for the centralized control. Sulfureted HPW/γ-FeO showed an excellent capacity to enrich gaseous Hg from low concentrations to ultra-high concentrations (>10 mg m), which benefited to condensing it into liquid Hg. Moreover, sulfureted HPW/γ-FeO exhibited excellent para-magnetism, enabling it to be magnetically reclaimed after Hg capture; this magnetization did not disappear after multiple thermal desorption of Hg due to its excellent thermal stability. Furthermore, sulfureted HPW/γ-FeO was regenerated by re-sulfuration without decreasing the Hg capture performance. Therefore, gaseous Hg recovery using sulfureted HPW/γ-FeO is a promising, economical-effective, and eco-friendly technology for the centralized control of Hg pollution emitted from power plants that burn coal with a high Hg content.
将气态元素汞（Hg）转化为颗粒状结合态汞（Hg）或通过催化剂转化为气态氧化态汞（Hg）并不适合控制燃烧富汞煤的电厂的汞排放，因为去除的汞可能会作为二次污染释放出来，特别是在使用粉煤灰和脱硫石膏时。在这项研究中，采用硫化磷钨酸修饰的γ-FeO（HPW/γ-FeO）作为一种磁性且可重复使用的吸附剂，用于集中控制从燃煤烟气中回收气态 Hg。硫化 HPW/γ-FeO 表现出从低浓度到超高浓度（>10 mg m）富集气态 Hg 的优异能力，有利于将其冷凝成液态 Hg。此外，硫化 HPW/γ-FeO 具有优异的顺磁性，使其在捕获 Hg 后可以通过磁场回收；由于其出色的热稳定性，多次热解吸 Hg 后这种磁化作用不会消失。此外，硫化 HPW/γ-FeO 可以通过再硫化再生，而不会降低 Hg 捕获性能。因此，使用硫化 HPW/γ-FeO 回收气态 Hg 是一种很有前景、经济有效且环保的技术，可以集中控制燃烧高汞含量煤的电厂的 Hg 污染。
