Metagenomic analysis of microbial community and metabolic pathway of simultaneous sulfide and nitrite removal process exposed to divergent hydraulic retention times

• Published in: Bioresource technology 2022-06, Vol.354, p.127186-127186, Article 127186
• Main Authors: Wang, Kaiquan, Qaisar, Mahmood, Chen, Bilong, Xiao, Jinghong, Cai, Jing
• Format: Article
• Language: English
• Subjects: Elemental sulfur generation; Functional genes; Nitrogen metabolism; Sulfur metabolism
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2022.127186

[Display omitted] •Optimum HRT for simultaneous removal of sulfide and nitrite process was 0.98 h.•Total S0 conversion percentage reached 93.61% at HRT of 0.25 h.•The S0 yield in the effluent increased with shortening of HRTs.•The community richness decreased with decreasing HRTs.•The expression of sulfur and nitrogen metabolism genes was investigated. The role of hydraulic retention time (HRT) on S0 production was assessed through metagenomics analyses. Considering comprehensive performance for the tested HRTs (0.25–13.33 h), the optimal HRT was 1 h, while respective sulfide and nitrite loading rate could reach 6.84 kg S/(m3·d) and 1.95 kg N/(m3·d), and total S0 yield was 0.36 kg S/(kg (VSS)·d). Bacterial community richness decreased along the shortening of HRT. Microbacterium, Sulfurimonas, Sulfurovum, Paracoccus and Thauera were highly abundant bacteria. During sulfur metabolism, high expression of sqr gene was the main reason of maintaining high desulfurization load, while lacking soxB caused the continuous increase of S0. Regarding nitrogen metabolism, the rapid decrease of nitrite transporter prevented nitrite to enter in cells, which caused a rapid decrease of nitrite removal under extreme HRT. Adjusting HRT is an effective way to enhance S0 production for the application of the simultaneous sulfide and nitrite removal process.