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Updated: Jul 24, 2026
15:19
Development of Sulfidogenic Sludge from Marine Sediments and Trichloroethylene Reduction in an Upflow Anaerobic Sludge Blanket Reactor
Published on: October 15, 2015
Sludge bed development in denitrifying reactors using different inocula-performance and microbiological aspects
C Etchebehere1, M I Errazquin, A Cabezas
1Cátedra de Microbiología, Facultad de Quimica, Udelar, Uruguay.
Summary
Methanogenic sludge effectively seeded denitrifying reactors, enhancing microbial activity and granule formation for wastewater treatment. Aerobic sludge failed to granulate due to Bacillus cereus contamination.
Area of Science:
- Environmental microbiology
- Wastewater treatment engineering
Background:
- Denitrification is crucial for removing nitrates from wastewater.
- Granular sludge technology offers efficient wastewater treatment.
- Selecting appropriate microbial consortia is key for successful granulation and denitrification.
Purpose of the Study:
- To evaluate aerobic and methanogenic consortia as inocula for laboratory-scale denitrifying reactors.
- To assess the impact of different inocula on granule formation and denitrification efficiency.
- To characterize the microbial communities involved in the process.
Main Methods:
- Laboratory-scale reactors fed with synthetic wastewater containing acetate.
- Monitoring of chemical oxygen demand (COD) and nitrate removal efficiencies.
- Microbial analysis including specific denitrifying activity, enumeration, isolation, and 16S rRNA gene sequencing.
Main Results:
- Methanogenic sludge successfully formed granules and demonstrated rapid adaptation to denitrification.
- Aerobic sludge failed to granulate, with Bacillus cereus identified as a potential inhibitory factor.
- Denitrifying activity increased over tenfold in reactors with methanogenic sludge.
- Granule size increased, but aggregate flotation due to gas retention was observed.
Conclusions:
- Methanogenic sludge is a suitable inoculum for developing denitrifying granular sludge reactors.
- Bacillus cereus can inhibit granule formation in aerobic systems.
- Further research is needed to mitigate granule flotation issues in denitrifying systems.
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