H2S removal and microbial community composition in an anoxic biotrickling filter under autotrophic and mixotrophic conditions

2019 
Abstract Removal of H 2 S from gas streams using NO 3 − –containing synthetic wastewater was investigated in an anoxic biotrickling filter (BTF) at feed N/S ratios of 1.2–1.7 mol mol −1 with an empty bed residence time of 3.5 min and a hydraulic retention time of 115 min. During 108 days of operation under autotrophic conditions, the BTF showed a maximum elimination capacity (EC) of 19.2 g S m −3  h −1 and H 2 S removal efficiency (RE) >99%. When the BTF was operated under mixotrophic conditions by adding organic carbon (10.2 g acetate m −3  h −1 ) to the synthetic wastewater, the H 2 S EC decreased from 16.4 to 13.1 g S m −3  h −1 , while the NO 3 − EC increased from 9.9 to 11.1 g NO 3 − –N m −3  h −1 , respectively. Thiobacillus sp. (98–100% similarity) was the only sulfur–oxidizing nitrate–reducing bacterium detected in the BTF biofilm, while the increased abundance of heterotrophic denitrifiers, i.e. Brevundimonas sp. and Rhodocyclales , increased the N/S ratio during BTF operation. Residence time distribution tests showed that biomass accumulation during BTF operation reduced gas and liquid retention times by 17.1% and 83.5%, respectively.
    • Correction
    • Source
    • Cite
    • Save
    • Machine Reading By IdeaReader
    41
    References
    34
    Citations
    NaN
    KQI
    []