Abstract A novel biochar containing highly-dispersed cobalt oxides was prepared by one-step pyrolysis using Co-enriched Siberian Iris as the raw material, and it was used for elemental mercury removal from flue gas. The presence of NO or HCl could approximately keep Hg0 removal efficiency over 85%, while the presence of SO2 suppressed Hg0 removal. The role of aforementioned acid gases in Hg0 removal over such biochar was systematically studied. The surface active oxygen species derived from the reversible conversion between Co3+ and Co2+ could activate the adsorbed NO (HCl) to produce active nitrogenous (chlorine) species, which functioned as active site for Hg0 oxidation removal. The reaction between NO (HCl) and Hg0 occurred mainly through the Eley-Rideal mechanism. SO2 consumed active oxygen and reacted with active Co3+ to generate Co2+ bonded with SO42−, resulting in irreversible damage on the biochar. The formation of active nitrogenous (chlorine) species as well as its reaction with Hg0 would be hampered by the generation of sulfate. This study can give some basic insights into the application of such heavy metal enriched phytoremediation plants for elemental mercury removal from flue gas.

中文翻译：

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酸性气体在从收获的富钴植物修复工厂制备的新型含钴生物炭上去除烟气中 Hg0 的作用

摘要 以富钴西伯利亚鸢尾为原料，通过一步热解制备了一种新型高分散氧化钴生物炭，用于烟气中元素汞的脱除。NO 或 HCl 的存在可使 Hg0 去除效率保持在 85% 以上，而 SO2 的存在抑制 Hg0 去除。系统地研究了上述酸性气体在通过这种生物炭去除 Hg0 中的作用。Co3+和Co2+之间的可逆转化产生的表面活性氧物质可以激活吸附的NO（HCl）以产生活性氮（氯）物质，作为Hg0氧化去除的活性位点。NO (HCl) 和 Hg0 之间的反应主要通过 Eley-Rideal 机制发生。SO2 消耗活性氧并与活性 Co3+ 反应生成与 SO42− 结合的 Co2+，对生物炭造成不可逆转的损害。活性含氮（氯）物质的形成及其与 Hg0 的反应将受到硫酸盐的生成的阻碍。这项研究可以为这种富含重金属的植物修复植物在烟道气中去除元素汞的应用提供一些基本的见解。