Understanding the Microbial Internal Storage Turnover in Wastewater Treatment: Retrospect, Prospect, and Challenge

Ni, Bing‐Jie; Yu, Han‐Qing; Zeng, Raymond J.

doi:10.1080/10643389.2013.876525

Cited by 11 publications

(4 citation statements)

References 58 publications

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“…The feed was provided under unaerated conditions (feast) during 95 min followed by an extended aeration period of 210 min (famine). This procedure was intended to avoid VFA consumption by Thiothrix and simultaneously favor the growth of accumulating microorganisms able to store biopolymers, mainly polyhydroxyalcanoate (PHA) under anaerobic conditions 16 .…”

Section: Resultsmentioning

confidence: 99%

Filamentous bulking caused by Thiothrix species is efficiently controlled in full-scale wastewater treatment plants by implementing a sludge densification strategy

Henriet

Meunier

Henry

et al. 2017

Sci Rep

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Filamentous bulking caused by Thiothrix species is responsible for sludge washout and loss of performance in dairy wastewater treatment plants. A long-term study was conducted over 1.5 years to test three different mitigation strategies in a full-scale plant composed of two parallel sequential batch reactors (SBR1 and 2). Strategies based on polyaluminium chloride addition and volatile fatty acids reduction were ineffective to permanently solve the problem. On the contrary, modification of the reactor cycle based on the implementation of a periodic starvation proved efficient to solve the biomass wash-out and drastically reduce the sludge volume index in both reactors. Bacterial diversity analysis using 16S amplicon sequencing and quantitative PCR indicated a reduction of Thiothrix abundance from 51.9 to 1.0% in SBR1 and from 71.8 to 0.6% in SBR2. Simultaneously, the abundance of the glycogen-accumulating bacterium Candidatus Competibacter increased in both reactors. Microscopy analysis confirmed the transition between a bulking sludge towards a granular-like sludge. This study confirms the applicability of a periodic starvation to (1) solve recurring Thiothrix bulking, (2) convert loose aggregates into dense and compact granular-like structures and (3) considerably reduce energy demand for aeration.

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Section: Resultsmentioning

confidence: 99%

Filamentous bulking caused by Thiothrix species is efficiently controlled in full-scale wastewater treatment plants by implementing a sludge densification strategy

Henriet

Meunier

Henry

et al. 2017

Sci Rep

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“…1 and 3), indicating the presence of GAOs in the RA system. Compared to PAOs, GAOs lead to increased N2O emission (Ni et al 2015) PHAs are considered to be the electron donor in the denitrification process; the presence of PHAs leads to competition with denitrifying enzymes, resulting in the accumulation of N2O. In this study, the amount of synthesized PHAs decreased as the proportion of propionate in the system increased.…”

Section: Factors Leading To Low N2o Production In the Rp Systemmentioning

confidence: 72%

N2O reduction during denitrifying phosphorus removal with propionate as carbon source

Wang

Jia

2021

Environ Sci Pollut Res

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Denitrifying phosphorus removal was realized in sequencing batch reactors using different carbons sources (acetate, propionate, and a mixture of acetate/propionate).Nutrient removal and N2O production were investigated, and the factors affecting N2O production were explored. Nitrogen removal was 40.6% lower when propionate was used as the carbon source instead of acetate, while phosphorus removal was not significantly different. N2O production was greatly reduced when propionate was used as the carbon source instead of acetate. The emission factor in the propionate system was only 0.43%, while those in the acetate and mixed-carbon source system were 16.3% and 1.9%, respectively. Compared to the propionate system, ordinary heterotrophic organisms (i.e., glycogen-accumulating organisms) were enriched in the acetate system, explaining the higher N2O production in the acetate system. The lower nitrite accumulation in the propionate system compared to the acetate system was the dominant factor leading to the lower N2O production.

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“…Dynamic process configurations, such as the sequencing batch reactor (SBR) in which the activated sludge is exposed to periods of feast and famine, induce storage behavior. Microorganisms capable of rapidly storing large amount of organics have a competitive advantage during the famine phase (van Loosdrecht et al., 1997 ; Ni et al., 2015 ). VFAs such as acetate will result in storage of PHAs whereas carbohydrates such as glucose will result in storage of glycogen (Carta et al., 2001 ).…”

Section: Nonoxidative Mechanisms For Organic Carbon Removalmentioning

confidence: 99%

Nonoxidative removal of organics in the activated sludge process

Modin

Persson

Wilén

et al. 2016

Critical Reviews in Environmental Science and Technology

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The activated sludge process is commonly used to treat wastewater by aerobic oxidation of organic pollutants into carbon dioxide and water. However, several nonoxidative mechanisms can also contribute to removal of organics. Sorption onto activated sludge can remove a large fraction of the colloidal and particulate wastewater organics. Intracellular storage of, e.g., polyhydroxyalkanoates (PHA), triacylglycerides (TAG), or wax esters can convert wastewater organics into precursors for high-value products. Recently, several environmental, economic, and technological drivers have stimulated research on nonoxidative removal of organics for wastewater treatment. In this paper, we review these nonoxidative removal mechanisms as well as the existing and emerging process configurations that make use of them for wastewater treatment. Better utilization of nonoxidative processes in activated sludge could reduce the wasteful aerobic oxidation of organic compounds and lead to more resource-efficient wastewater treatment plants.

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Understanding the Microbial Internal Storage Turnover in Wastewater Treatment: Retrospect, Prospect, and Challenge

Cited by 11 publications

References 58 publications

Filamentous bulking caused by Thiothrix species is efficiently controlled in full-scale wastewater treatment plants by implementing a sludge densification strategy

Filamentous bulking caused by Thiothrix species is efficiently controlled in full-scale wastewater treatment plants by implementing a sludge densification strategy

N2O reduction during denitrifying phosphorus removal with propionate as carbon source

Nonoxidative removal of organics in the activated sludge process

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