Functional Microbial Communities in Hybrid Linear Flow Channel Reactors for Desulfurization of Tannery Effluent

Area of Science:

• Environmental microbiology
• Wastewater treatment technologies
• Bioreactor engineering

Background:

• Hybrid linear flow channel reactors (HLFCRs) show potential for tannery effluent desulfurization.
• These reactors facilitate sulfate reduction and elemental sulfur recovery.
• HLFCRs can pre-treat effluent, enhancing downstream anaerobic digestion.

Purpose of the Study:

• Investigate bacterial communities within series-operated HLFCRs.
• Determine structure-function relationships in these microbial communities.
• Assess the role of bioaugmentation in HLFCR performance.

Main Methods:

• Amplicon sequencing of the 16S rRNA gene to profile bacterial communities.
• Quantification of the dissimilatory sulfite reducing (dsrB) gene.
• Analysis of microbial consortia from saline estuaries and tannery wastewater.

Main Results:

• Native tannery wastewater bacteria were selected over enriched consortia; bioaugmentation was unnecessary.
• Dethiosulfovibrio sp. and Petrimonas sp. were strongly selected.
• Desulfobacterium autotrophicum and Desulfobacter halotolerans dominated sulfate-reducing bacteria.

Conclusions:

• HLFCRs effectively select for specific bacterial communities during tannery effluent treatment.
• The dominance of elemental sulfur-reducing genera (Dethiosulfovibrio, Petrimonas) is a concern for system efficiency.
• Strategies to mitigate the selection of undesirable genera are needed for optimal HLFCR performance.