Influence of cycle time on kinetic behaviors of steady-state aerobic granules in sequencing batch reactors

2007 ◽  
Vol 41 (4) ◽  
pp. 516-522 ◽  
Author(s):  
Yong-Qiang Liu ◽  
Joo-Hwa Tay
2012 ◽  
Vol 66 (8) ◽  
pp. 1722-1727 ◽  
Author(s):  
Lin Liu ◽  
Da-Wen Gao ◽  
Hong Liang

We have investigated the effect of sludge discharge location on the steady-state aerobic granules in sequencing batch reactors (SBRs). Two SBRs were operated concurrently with the same sludge retention time using sludge discharge ports at: (a) the reactor bottom in R1; and (b) the reactor middle-lower level in R2. Results indicate that both reactors could maintain sludge granulation and stable operation, but the two different sludge discharge methods resulted in significantly different aerobic granule characteristics. Over 30 days, the chemical oxygen demand (COD) removal of the two reactors was maintained at similar levels (above 96%), and typical bioflocs were not observed. The average aerobic granule size in R2 was twice that in R1, as settling velocity increased in proportion to size increment. Meanwhile, the production yields of polysaccharide and protein content in R2 were always higher than those in R1. However, due to mass transfer limitations and the presence of anaerobes in the aerobic granule cores, larger granules had a tendency to disintegrate in R2. Thus, we conclude that a sludge discharge port situated at the reactor bottom is beneficial for aerobic granule stability, and enhances the potential for long-term aerobic granule SBR operation.


2020 ◽  
Vol 389 ◽  
pp. 121905 ◽  
Author(s):  
Alfonz Kedves ◽  
Levente Sánta ◽  
Margit Balázs ◽  
Péter Kesserű ◽  
István Kiss ◽  
...  

2016 ◽  
Vol 42 (1) ◽  
pp. 74-79 ◽  
Author(s):  
Agnieszka Cydzik-Kwiatkowska ◽  
Paulina Rusanowska ◽  
Katarzyna Głowacka

Abstract The elemental composition and morphology of aerobic granules in sequencing batch reactors (GSBRs) treating high-nitrogen digester supernatant was investigated. The investigation particularly focused on the effect of the number of anoxic phases (one vs. two) in the cycle and the dose of external organics loading (450 mg COD/(L·cycle) vs. 540 mg COD/(L·cycle)) on granule characteristics. Granules in all reactors were formed of many single cells of rod and spherical bacteria. Addition of the second anoxic phase in the GSBR cycle resulted in enhanced settling properties of the granules of about 10.6% and at the same time decreased granule diameter of about 19.4%. The study showed that external organics loading was the deciding factor in the elemental composition of biomass. At 540 mg COD/(L·cycle) the granules contained more weight% of C, S and N, suggesting more volatile material in the granule structure. At lower organics loadings granules had the higher diameter of granules which limited the diffusion of oxygen and favored precipitation of mineral compounds in the granule interior. In this biomass higher content of Mg, P and Ca, was observed.


2010 ◽  
Vol 86 (6) ◽  
pp. 1967-1975 ◽  
Author(s):  
Xin-Hua Wang ◽  
Li-Hong Gai ◽  
Xue-Fei Sun ◽  
Hui-Jun Xie ◽  
Ming-Ming Gao ◽  
...  

2013 ◽  
Vol 16 (1) ◽  
pp. 40-48
Author(s):  
Phuong Thi Thanh Nguyen ◽  
Phuoc Van Nguyen ◽  
Anh Cam Thieu

Aerobic granular sludge has attracted extensive interest of researchers since the 90s due to the advantages of aerobic granules such as good settling ability, high biomass accumulation, being resistant to high loads and being less affected by toxic substances. Studies, however, which have mainly been carried out on synthetic wastewater, cannot fully evaluate the actual ability of aerobic granules. Study on aerobic granular sludge was performed in sequencing batch reactors, using seeding sludge taken from anaerobic sludge and tapioca wastewater as a substrates. After 11 weeks of operation, the granules reached the stable diameter of 2- 3 mm at 3.7 kgCOD/m3.day organic loading rate. At high organic loads, in range of 1.6 - 5 kgCOD/m3.day, granules could treat effectively COD, N, P with performance of 93 – 97%; 65 – 79% and 80 – 95%, respectively.


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