The present work aims to develop a novel and sustainable approach to adsorb and recover low-concentration Hg0 in the off-gas downstream a distillation/condensation system in the recycling processes for waste Hg-containing devices. Hg0 adsorption and regeneration efficiencies of raw and HNO3-treated activated carbon fiber cloth (ACFC) were examined. The adsorption experiments were conducted with an initial Hg0 concentration of 260-300 μg/m3 at room temperature. The regeneration of ACFC was done by an electrothermal swing process with 20, 40, and 60 W direct currents. The experimental results showed that the Hg0 adsorption efficiency of raw ACFC increased to approximately 90% after the 60 W electrothermal regeneration. After HNO3 treatment, the content of oxygen functional groups on HNO3-treated ACFC increased, which enhanced the Hg0 adsorption performance and resulted in over 90% adsorption efficiency for the samples before and after electrothermal regeneration. Importantly, both raw and HNO3-treated ACFCs retained the high adsorption efficiency after nine cycles of adsorption/regeneration, indicating that both raw and HNO3-treated ACFCs were effective and renewable adsorbents for low-concentration Hg0 adsorption and recovery. A Hg adsorption/regeneration mechanism was proposed to explain the increasing adsorption efficiency after electrothermal regeneration and the great adsorption efficiency of HNO3-treated ACFC.

中文翻译：

---

使用活性碳纤维布通过吸附和电热解吸可持续回收气态汞。

本工作旨在开发一种新颖且可持续的方法，以在含汞废物装置的回收过程中，在蒸馏/冷凝系统下游的废气中吸附和回收低浓度的Hg0。检查了生料和经HNO3处理的活性炭纤维布（ACFC）的Hg0吸附和再生效率。在室温下，初始Hg0浓度为260-300μg/ m3进行吸附实验。通过使用20、40和60 W直流电的电热摆动过程完成ACFC的再生。实验结果表明，在60 W电热再生后，粗ACFC的Hg0吸附效率提高到大约90％。HNO3处理后，HNO3处理的ACFC上的氧官能团含量增加，增强了Hg0的吸附性能，并在电热再生之前和之后使样品的吸附效率超过90％。重要的是，经过九次吸附/再生循环后，未经处理和经HNO3处理的ACFC均保持了高吸附效率，这表明未经处理和经HNO3处理的ACFC都是有效的可再生吸附剂，用于低浓度Hg0的吸附和回收。提出了汞吸附/再生机理，以解释电热再生后吸附效率的提高和经HNO3处理的ACFC的巨大吸附效率。在经过9个吸附/再生循环后，原始和HNO3处理的ACFC均保留了高吸附效率，这表明原始和HNO3处理的ACFC都是有效的可再生吸附剂，用于低浓度Hg0的吸附和回收。提出了汞吸附/再生机理，以解释电热再生后吸附效率的提高和经HNO3处理的ACFC的巨大吸附效率。在经过9个吸附/再生循环后，原始和HNO3处理的ACFC均保持了高吸附效率，这表明原始和HNO3处理的ACFC都是有效的可再生吸附剂，用于低浓度Hg0的吸附和回收。提出了汞吸附/再生机理，以解释电热再生后吸附效率的提高和经HNO3处理的ACFC的巨大吸附效率。