To enhance the performance of activated carbon (AC) for elemental mercury removal, a kind of AC was modified by nonthermal plasma (NTP) and the effects of the modification of the atmosphere (N₂, O₂, air, and HCl) were investigated by adsorption and desorption experiments. The physical and chemical properties of original and modified ACs were characterized by Brunauer–Emmett–Teller, scanning electron microscopy with energy-dispersive spectroscopy, and X-ray photoelectron spectroscopy (XPS). The results showed that better mercury removal performance of ACs was obtained after modifying by NTP in air, O₂, and HCl. The mercury removal efficiency of AC–air, AC–O₂, and AC–HCl was obviously enhanced compared to the raw AC and AC–N₂ attributed to the large increase of oxygen-containing functional groups [C═O and C(O)–O–C] occurring on the AC surface. AC treated in HCl could form C–Cl groups, which were beneficial to improve its oxidizing ability. In addition, stronger etching and cracking on the AC surface during NTP modification in an O₂ or a HCl atmosphere were found to decrease its specific surface area and micropore volume, resulting in an adverse effect on mercury removal. It was found that the desorption peaks at 290 and 340 °C of the adsorbed AC samples corresponded to carbonyl groups (C═O) and ester groups [C(O)–O–C], respectively, which were verified by combining the results of XPS and temperature-programmed desorption experiments.

中文翻译：

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非大气等离子体处理活性炭提高大气中汞的去除率

为了提高活性炭（AC）去除元素汞的性能，通过非热等离子体（NTP）对一种AC进行了改性，并研究了改性气氛（N ₂，O ₂，空气和HCl）的影响通过吸附和解吸实验。原始AC和改性AC的物理和化学特性通过Brunauer-Emmett-Teller，带能谱的扫描电子显微镜和X射线光电子能谱（XPS）进行了表征。结果表明，通过NTP在空气，O ₂和HCl中改性后，AC的除汞性能更好。与原始AC和AC-N相比，AC-空气，AC-O ₂和AC-HCl的除汞效率明显提高₂归因于AC表面上含氧官能团[C═O和C（O）–OC]的大量增加。用HCl处理的AC可以形成C–Cl基团，有利于提高其氧化能力。此外，发现在O ₂或HCl气氛中进行NTP改性时，在AC表面上更强的蚀刻和开裂会降低其比表面积和微孔体积，从而对除汞产生不利影响。结果表明，吸附的AC样品在290和340°C的解吸峰分别对应于羰基（C═O）和酯基[C（O）–O–C]，并结合结果进行了验证。 XPS和程序升温脱附实验。