Biomass Carbon Magnetic Adsorbent Constructed by One-Step Activation Method for the Removal of Hg 0 in Flue Gas.

Elemental mercury (Hg 0 ) emission from industrial boilers equipped in factories such as coal-fired power plants poses serious hazards to the environment and human health. Herein, an iron-modified biomass carbon (Fe/BC) magnetic adsorbent was prepared by a one-step method using pepper straw waste as raw material and potassium oxalate and ferric nitrate as activator and catalyst precursor, respectively. A fixed-bed reactor was used to evaluate the Hg 0 removal performance of the Fe/BC adsorbent. The synthesized adsorbent showed a wide temperature window for Hg 0 removal. In a N 2 + O 2 atmosphere, the removal efficiency toward Hg 0 was 97.6% at 150 °C. Further, O 2 or SO 2 could promote the removal of Hg 0 , while NO could inhibit the conversion of Hg 0 over the Fe/BC adsorbent. The consequence of XPS and Hg-TPD showed that lattice oxygen in Fe 2 O 3 and chemisorbed oxygen were the main active sites for Hg 0 removal, and HgO was the main mercury species on used Fe/BC. Moreover, Fe/BC adsorbent showed a good regeneration and magnetization performance, which was conducive to the cost reduction of actual industrial application. This study provides a facile approach for efficient removal of Hg 0 using biomass-derived carbon material.