Removal of hydrogen sulfide (H₂S) with Thiobacillus denitrificans biofilter: study of the microbial community conducted through 16S rRNA sequencing analysis

Hydrogen sulfide (H₂S) emissions from oil and gas operations, sewage treatment facilities, and landfills are challenges to the quality of life. The main objective of this work is to study the effect of different filter packing materials on Thiobacillus denitrificans-mediated lab-scale bioreactor for H₂S removal using 16S rRNA metagenomic sequencing. In this study, the bioreactor column, which has three distinct layers of Ceramic Ball Filter Media (CBFM), Filter Media Ceramic Rings (FMCR), and Filter Bio Balls (FBB), was designed and operated for 60 days. The microbial community samples adhered to the surfaces of the filling materials were investigated using 16S rRNA metagenomic sequencing with paired-end 2 × 150 base reads (Illumina). The results showed that the H₂S gas removal efficiency reached its maximum of 99% by the end of the seventh day, followed by a steady-state pattern. Compared with polypropylene surfaces, ceramic materials successfully hosted the T. denitrificans bacteria. Changing the filter material altered the phylum species diversity of the microcosms on the filter material, as shown by alpha diversity indices (Shannon and Simpson values). The dominant Phylum across all samples, regardless of the treatment and filter material type, was Proteobacteria, followed by Firmicutes and Bacteroidetes. Comamonas thiooxydans, Comamonas testosterone, Enterococcus faecalis, Staphylococcus aureus, Staphylococcus cohnii, and Mesorhizobium terrae are the most abundant species detected on the filter materials. In addition, changing the filter material causes a substantial alteration of the dominant species in the microcosm of the bioreactor. These findings highlight the critical role of filter material in supporting H₂S-removing microorganisms.