Wastewater treatment and microbial community dynamics in a sequencing batch reactor operating under photosynthetic aeration
| Autor: | Kai-Chee Loh, Yen Wah Tong, Sheetal Kishor Parakh, Prashant Praveen |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Environmental Engineering
Health Toxicology and Mutagenesis 0208 environmental biotechnology Photobioreactor Sequencing batch reactor 02 engineering and technology 010501 environmental sciences Wastewater 01 natural sciences Waste Disposal Fluid Bioreactor Environmental Chemistry Photosynthesis 0105 earth and related environmental sciences Chemistry Microbiota Public Health Environmental and Occupational Health General Medicine General Chemistry Pulp and paper industry Pollution 020801 environmental engineering Activated sludge Sewage treatment Nitrification Aeration |
| Zdroj: | Chemosphere. 215 |
| ISSN: | 1879-1298 |
| Popis: | A sequencing batch bioreactor (SBR) treating municipal wastewater was photosynthetically aerated using microalgae cultivated in a photobioreactor (PBR). Symbiotic interactions and CO2/O2 exchange were established between activated sludge in the SBR and microalgae in the PBR through hydrophobic hollow fiber membranes. Photosynthetic aeration enhanced COD removal in the SBR from 52.2% (without external aeration) to 90.3%, whereas N-NH4+ and P-PO43- removal increased by 63.5% and 90.4%, respectively. The SBR performance under photosynthetic aeration was comparable to that under mechanical aeration. However, no nitrification was observed in the SBR, indicating oxygen limitation and poor growth condition for nitrifiers. In the PBR, there was a rapid increase in biomass concentration and it stabilized at 3.0 g/L after 22 days of operation. High nitrogen demand in the PBR indicated the steady flow of inorganic carbon from the SBR through the membranes. Prolonged oxygen limitation and massive sludge attachment on the membranes resulted in low suspended sludge concentration in the SBR. Microbial community analysis indicated gradual enrichment of facultative and strictly anaerobic microorganisms in the SBR. These results highlight the potential of microalgae in lowering the cost of wastewater aeration and underline the challenges in sustaining symbiotic gas exchange during long-term. |
| Databáze: | OpenAIRE |
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