LAUSR

Abstract Elemental mercury (Hg0) is becoming more alarming toxic pollutant due to its high persistence in the environment. However, advanced oxidation/adsorption techniques could be the major routes of Hg0 removal by a suitable adsorbent. For this purpose, a highly competitive and regenerable magnetic tea biochar (MTBC) was developed by one-step pyrolysis of Fe(NO3)3 laden waste tea leaves at 500 ℃ and characterized by analytical techniques such as BET, XRD, VSM, SEM, TGA, and XPS. The Hg0 removal mechanism via adsorption/oxidation from simulated syngas was investigated under a wide reaction temperature range (60 ℃–300 ℃). Results revealed that the MTBC with an optimal loading of 0.46 mol/L Fe(NO3)3, attained an approximately ≥ 95% of Hg0 removal efficiency (ηT) at 180 ℃ under simulated syngas (10% CO, 10% H2, and 400 H2S). The TBCFe 0.46 exhibited high H2O resistance under simulated syngas, although a slight decrease was received in ηT at 10 vol% H2O. After six repeated adsorption/regeneration cycles, the ηT value was still above 90%. Consequently, the waste tea derived regenerable sorbent TBCFe 0.46 with high Hg0 adsorption performance makes it an inexpensive, excellent recyclable catalyst to control mercury emission from coal syngas.