Impact of fungal pellets dosage on long-term stability of aerobic granular sludge

2021 ◽  
Vol 332 ◽  
pp. 125106
Author(s):  
Mingyue Geng ◽  
Shijie You ◽  
Haijuan Guo ◽  
Fang Ma ◽  
Xiao Xiao ◽  
...  
Keyword(s):  
Granular Sludge ◽  
Aerobic Granular Sludge ◽  
Term Stability ◽  
Long Term Stability ◽  
Fungal Pellets

scholarly journals Long-term stability of a non-adapted aerobic granular sludge process treating fish canning wastewater associated to EPS producers in the core microbiome

2021 ◽  
Vol 756 ◽  
pp. 144007
Author(s):  
Ana M.S. Paulo ◽  
Catarina L. Amorim ◽  
Joana Costa ◽  
Daniela P. Mesquita ◽  
Eugénio C. Ferreira ◽  
...  
Keyword(s):  
Granular Sludge ◽  
Aerobic Granular Sludge ◽  
Core Microbiome ◽  
Term Stability ◽  
Long Term Stability ◽  
The Core

scholarly journals Fluctuation and Re-Establishment of Aerobic Granules Properties during the Long-Term Operation Period with Low-Strength and Low C/N Ratio Wastewater

Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1290
Author(s):  
Lijuan Cha ◽  
Yong-Qiang Liu ◽  
Wenyan Duan ◽  
Christain E. W. Sternberg ◽  
Qiangjun Yuan ◽  
...  
Keyword(s):  
Biomass Concentration ◽  
Granular Sludge ◽  
Volume Index ◽  
Synthetic Wastewater ◽  
Aerobic Granules ◽  
Term Stability ◽  
Long Term Stability ◽  
Low Strength ◽  
External Intervention

Long-term structure stability of aerobic granules is critical to maintaining stable wastewater treatment performance. In this study, granulation and long-term stability of sludge-treating synthetic wastewater with a low chemical oxygen demand to nitrogen (COD/N) ratio of 4:1 and COD concentration of 400 mg/L in anoxic-oxic conditions were investigated for over 300 days. Inoculated suspended sludge gradually transformed into granules-dominant sludge on day 80. Due to the improved sludge volume index after 30 min settling (SVI30), mixed liquor suspended solids (MLSS) reached 5.2 g/L on day 140. Without any external intervention or disturbance, aerobic granules started to disintegrate from day 140, causing the increase in SVI and the decrease in biomass concentration until day 210, with the average sludge size reduced to 243 µm. From day 210, granular sludge started to be re-established by re-granulation, and the average granule size increased to 500 µm on day 302. During these disintegration and re-granulation periods, there was no obvious difference in terms of COD removal and nitrification, but microbial species were found more diverse after the re-granulation, with Thauera and Sphingomonas dominant. Although there was no external intervention, the food to microorganisms ratio (F/M) varied significantly due to the changes in biomass concentration caused by strong selective pressure and the change of sludge-settling ability in the reactor. F/M ratios should be controlled between 0.3 and 1.0 gCOD/gSS·d to maintain the stable structure of granules to minimize the fluctuation of sludge properties under the conditions used in this study. Although aerobic granular sludge is able to re-establish itself after disintegration, controlling F/M ratios in a certain range would benefit long-term stability. The findings in this study are significant to deepen the understanding of granule stability with low-strength and low COD ratio wastewater and, thus, provide guidance for maintaining the long-term stability of granules.

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