Evaluation of H2S gas removal by a biotrickling filter: Effect of oxygen dose on the performance and microbial communities.

A cost-efficient and environmentally friendly biofiltration system is essential for desulfurization to recover elemental sulfur and sulfate for extensively remediating H 2 S. This work investigated the H 2 S removal capacity, accumulation of desulfurization products, sulfur balance, microbial community, and the pathway for sulfide oxidation under different O 2 doses (1%, 3%, 5%, and 10%). The results showed that the removal efficiency of H 2 S increased from 94.1% to 100.0% with the increase of O 2 dose. At 1% O 2 , the elimination capacity (EC) was 5.72 ± 0.33 gH 2 S m–3 h–1, and about 78.13% of S0-S was generated. However, with stepwise increase of O 2 concentration to 10%, the EC became 6.00 ± 0.35 gH 2 S m–3 h–1, and SO 4 2–-S was the dominant product at 80.39%. Furthermore, the sulfur balance was verified by calculating the proportion of sulfur compounds (S0-S, SO 4 2−-S, and SO 3 2−-S) and comparing the microstructure of packing material in the biotrickling filter. Moreover, 16 S rRNA high-throughput sequencing analysis showed that the cooperation of sulfur-oxidizing bacteria in the biofiltration system was the key to the stable and efficient removal of H 2 S. In addition, possible reaction pathways in which H 2 S was transformed to S0 and SO 4 2− were proposed. [Display omitted] [ABSTRACT FROM AUTHOR]