This study aims to compare the biological degradation performance of ethanethiol using strain RG-1 and B350 commercial mixed microorganisms, which were inoculated and immobilized on ceramic particles in twin-biotrickling filter columns. The parameters affecting the removal efficiency, such as empty bed residence time (EBRT) and inlet concentration, were investigated in detail. When EBRT ranged from 332 to 66s at a fixed inlet concentration of 1.05 mgL(-1), the total removal efficiencies for RG-1 and B350 both decreased from 100% to 70.90% and 47.20%, respectively. The maximum elimination capacities for RG-1 and B350 were 38.36 (removal efficiency = 89.20%) and 25.82 gm(-3)h(-1) (removal efficiency = 57.10%), respectively, at an EBRT of 83 s. The variation of the inlet concentration at a fixed EBRT of 110s did not change the removal efficiencies which remained at 100% for RG-1 and B350 at concentrations of less than 1.05 and 0.64 mgL(-1), respectively. The maximum elimination capacities were 39.93 (removal efficiency = 60.30%) and 30.34 gm(-3)h(-1) (removal efficiency = 46.20%) for RG-1 and B350. respectively, at an inlet concentration of 2.03 mgL(-1). Sulfate was the main metabolic product of sulfur in ethanethiol. Based the results, strain RG-1 would be a better choice than strain B350 for the biodegradation of ethanethiol. (C) 2010 Elsevier B.V. All rights reserved.