Biogas desulfurization under anoxic conditions using synthetic wastewater and biogas slurry

A feasibility study was conducted to determine whether aerated biogas slurry is a suitable nutrient solution for biogas desulfurization systems with a biotrickling filter. At a loading rate of 36.20 g-H₂S m⁻³h⁻¹, the H₂S and NO_x ⁻-N removal efficiencies were 84.7% (average elimination capacity of 30.67 g-H₂S m⁻³h⁻¹) and 60.9%, respectively, when utilizing synthetic wastewater in a simultaneous biogas desulfurization and wastewater denitrification system. However, these efficiencies were just 61.9% (average elimination capacity of 22.42 g-H₂S m⁻³h⁻¹) and 49.2%, respectively, when biogas slurry was used. High-throughput sequencing revealed that the Thiobacillus and Sulfurimonas genera were the main functional bacteria. Alpha- and beta-diversity analyses showed that the H₂S loading rate significantly affected the microbial community structure, especially in the system utilizing aerated biogas slurry. Finally, based on the results, we describe a feasible approach to using biogas slurry for biogas desulfurization.