Treatment of Sugar Containing-Low Strength Wastewater at 20°C by Anaerobic Granular Sludge Bed Reactor

2010 ◽  
Vol 5 (3) ◽  
Author(s):  
W. Yoochatchaval ◽  
K. Kubota ◽  
T. Kawai ◽  
T. Yamaguchi ◽  
K. Syutsubo
Keyword(s):  
Stable Process ◽  
Growth Yield ◽  
High Growth ◽  
Granular Sludge ◽  
Post Treatment ◽  
Cod Removal ◽  
Synthetic Wastewater ◽  
Anaerobic Granular Sludge ◽  
Treatment Technology ◽  
Low Strength

To investigate the feasibility of anaerobic wastewater treatment technology for low strength sugar refinery wastewater (0.4 - 0.5 g COD/L), an 8.8 L volume of anaerobic granular sludge bed reactor was operated at 20°C for 400 days. The operation mode was combination of one pass flow (UASB, 50 min) and effluent-recirculation (EGSB, 10 min) mode. The aerobic down-flow hanging sponge (DHS) reactor was installed as a post-treatment. During the started-up period, reactors were fed with synthetic wastewater at overall HRT of 3 hours (anaerobic 2 hours, aerobic 1 hour). After day 85, feed was changed to real wastewater together with supplement of nutrients, trace elements and NaHCO3. The sufficient COD removal efficiency (85% SD±6.2) and stable process performance were elicited from the granular sludge bed reactor.Also, post-treatment (DHS reactor) offered good quality of effluent (45 mg COD/L, 7 mg BOD/L) and it achieved the discharge standard. Increasing of sulfate concentration of wastewater caused higher contribution of sulfate reducing bacteria for COD removal. The sludge concentration and settleability were well maintained thoroughly. However, floatation of large size granule was observed in the later part of experiment. This phenomenon may attribute to the high growth yield of retained sludge at 20°C.

Nutrient removal and microbial granulation in an anaerobic process treating inorganic and organic nitrogenous wastewater

2004 ◽  
Vol 50 (6) ◽  
pp. 207-215 ◽  
Author(s):  
Y.-H. Ahn ◽  
H.-C. Kim
Keyword(s):  
Nitrogen Removal ◽  
Nutrient Removal ◽  
Granular Sludge ◽  
Synthetic Wastewater ◽  
Anaerobic Granular Sludge ◽  
Ammonium Oxidation ◽  
Ammonium Removal ◽  
Activity Test ◽  
Nitrite Nitrate ◽  
Inorganic And Organic

The sustainable anaerobic nitrogen removal and microbial granulation were investigated by using a laboratory anaerobic granular sludge bed reactor, treating synthetic (inorganic and organic) wastewater and piggery waste. From inorganic synthetic wastewater, lithoautotrophic ammonium oxidation to nitrite/nitrate was observed by an addition of hydroxylamine. Also, the results revealed that the Anammox intermediates (particularly, hydrazine) contents in the substrate would be one of the important parameters for success of the anaerobic nitrogen removal process. The results from organic synthetic wastewater show that if the Anammox organism were not great enough in the startup of the process, denitritation and anaerobic ammonification would be a process prior to the Anammox reaction. The anaerobic ammonium removal from the piggery waste was performed successfully, probably due to the Anammox intermediates contained in the substrate. This reactor shows a complex performance including the Anammox reaction and HAP crystallization, as well as having partial denitritation occurring simultaneously. From the activity test, the maximum specific N conversion rate was 0.1 g NH4-N/g VSS/day (0.77 g T-N/g VSS/day), indicating that potential denitritation is quite high. The NO2-N/NH4-N ratio to Anammox is 1.17. The colour of the biomass treating the piggery waste changed from black to dark red. It was also observed that the red-colored granular sludge had a diameter of 1-2 mm. The settleability assessment of the granular sludge revealed that the granular sludge had a good settleability even though it was worse than that of seed granular sludge.

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.

Removal of COD from Piggery Wastewater Using a Lab-Scale UASB Reactor

2012 ◽  
Vol 534 ◽  
pp. 221-224
Author(s):  
Fei Yan ◽  
Jin Long Zuo ◽  
Tian Lei Qiu ◽  
Xu Ming Wang
Keyword(s):  
Granular Sludge ◽  
Cod Removal ◽  
Upflow Anaerobic Sludge Blanket ◽  
Synthetic Wastewater ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Volume Loading ◽  
Piggery Wastewater ◽  
Start Up ◽  
Anaerobic Sludge Blanket

It took 55 days to start up a lab-scale upflow anaerobic sludge blanket (UASB) reactor at ambient temperature 27-28 oC by using the synthetic wastewater, and piggery wastewater was used as the influent after the reactor start-up. From day 120 onwards, COD removal efficiency maintained in the range of 85% to 95% with 6.79-9.66 kg COD/ (m3•d) of volume loading, and the effluent COD concentration ranged between 400 mg/L and 600 mg/L. Granular sludge formation was observed in the reactor after 40-day operation, and the sludge diameter reached 2-4 mm in the 120 day-old reactor. The pH changes in the influent had little influence on COD removal from piggery wastewater using the UASB reactor.

Evaluation of UASB Reactor Performance During Start-Up Operation Using Glucose Bearing Synthetic Wastewater

2020 ◽  
Vol 9 (1) ◽  
pp. 32-51
Author(s):  
Revanuru Subramanyam
Keyword(s):  
Removal Efficiency ◽  
Loading Rate ◽  
Granular Sludge ◽  
Cod Removal ◽  
Synthetic Wastewater ◽  
Organic Loading Rate ◽  
Anaerobic Sludge ◽  
Cod Removal Efficiency ◽  
Start Up ◽  
Seed Sludge

This research article describes start-up performance of an UASB (Upflow Anaerobic Sludge Blanket) reactor in terms of chemical oxygen demand (COD) removal efficiency, biogas production, sludge loading rate (SLR), volatile fatty acids (VFA), pH, alkalinity, total solids (TS) and volatile suspended solids (VSS), fed with synthetic wastewater with increased concentrations of glucose. The reactor was loaded up to an OLR (Organic Loading Rate) of 15 kg COD m-3 d-1 and achieved a COD removal efficiency of 82 ±3%. The results showed that digested seed sludge was successfully acclimatized and transformed finally into granular sludge within a period of 120 days. An increase in the accumulation of VFA at high OLRs showed that methanogenesis could be the rate-limiting step in the reactor operation. The SLR and VSS/TS ratio were increased with an increase in OLR. During the initial stages, uniform distribution of VSS concentration and later on maximum VSS concentration were found at port number two at a height of 350 mm. The carbon balance depicts that the maximum percentage of influent COD converted to methane COD. An increase in specific methanogenic activity values with the age of sludge confirmed the transformation of the seed sludge in to a granular sludge.

Kinetics of aerobic granular sludge treating low-strength synthetic wastewater at high dissolved oxygen

2018 ◽  
Vol 41 (11) ◽  
pp. 1455-1463 ◽  
Author(s):  
Tanner Ryan Devlin ◽  
Maciej S. Kowalski ◽  
Alessandro di Biase ◽  
Jan A. Oleszkiewicz
Keyword(s):  
Dissolved Oxygen ◽  
Granular Sludge ◽  
Synthetic Wastewater ◽  
Aerobic Granular Sludge ◽  
Low Strength ◽  
Kinetics Of

scholarly journals Anaerobic granular sludge for simultaneous biomethanation of synthetic wastewater and CO with focus on the identification of CO-converting microorganisms

2017 ◽  
Vol 126 ◽  
pp. 19-28 ◽  
Author(s):  
Yuhang Jing ◽  
Stefano Campanaro ◽  
Panagiotis Kougias ◽  
Laura Treu ◽  
Irini Angelidaki ◽  
...  
Keyword(s):  
Granular Sludge ◽  
Synthetic Wastewater ◽  
Anaerobic Granular Sludge

scholarly journals Psychrophilic anaerobic treatment of low strength wastewaters

1999 ◽  
Vol 39 (5) ◽  
pp. 203-210 ◽  
Author(s):  
Salih Rebac ◽  
Jules B. van Lier ◽  
Piet Lens ◽  
Alfons J. M. Stams ◽  
Freddy Dekkers ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Volatile Fatty Acids ◽  
Oxygen Demand ◽  
Granular Sludge ◽  
Anaerobic Treatment ◽  
Cod Removal ◽  
High Rate ◽  
Organic Loading Rate ◽  
Substrate Conversion ◽  
Low Strength

Psychrophilic (2 to 20°C) anaerobic treatment of low strength synthetic and malting wastewater was investigated using a single and two module expanded granular sludge bed (EGSB) reactor system. The chemical oxygen demand (COD) removal efficiencies found in the experiments exceeded 90 % in the single module reactor at an organic loading rate up to 12 g COD dm−3 day−1 and a HRT of 1.6 h at 10-12°C ambient temperature using influent concentrations ranging from 500 to 800 mg COD dm−3. When a two module EGSB system was used at the temperature range 10-15°C, soluble COD removal and volatile fatty acids removal of 67-78% and 90-96% were achieved, respectively, and an OLR between 2.8-12.3 kg COD m−3 day−1 and a HRT of 3.5 h. The second module serves mainly as a scavenger of non-degraded volatile fatty acids (VFA) from the first module. The optimal temperatures for substrate conversion of reactor sludge, after it has been exposed to long term psychrophilic conditions, were similar to those of the original mesophilic inoculum. The specific activities of the sludge in the reactor increased in time by a factor 3, indicating enrichment of methanogens and acetogens even at low temperatures. By adapting the process design to the expected prevailing conditions inside the reactor, the loading potentials and overall stability of the anaerobic high-rate process may be distinctly improved under psychrophilic conditions. The results obtained clearly reveal the big potentials of anaerobic wastewater treatment under low ambient (10-12°C) temperature conditions for low strength wastewaters, very likely including domestic sewage.

Influence of effluent-recirculation condition on the process performance of expanded granular sludge bed reactor for treating low strength wastewater

2008 ◽  
Vol 57 (6) ◽  
pp. 869-873 ◽  
Author(s):  
W. Yoochatchaval ◽  
K. Nishiyama ◽  
M. Okawara ◽  
A. Ohashi ◽  
H. Harada ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Physical Property ◽  
Granular Sludge ◽  
Cod Removal ◽  
Process Performance ◽  
Methanogenic Activity ◽  
Cod Removal Efficiency ◽  
Start Up ◽  
Effluent Recirculation ◽  
Low Strength

A 2.0 L volume of EGSB reactor was operated at 20°C for more than 500 days with 0.3–0.4 g COD/L of sucrose base wastewater to investigate the influence of effluent-recirculation on the process performance. At the start up period, the reactor was operated in EGSB mode with 5 m/h upflow velocity by continuous effluent recirculation. The COD loading was set to 7.2–9.6 kg COD/m3 day with HRT of 1 hour. However, in this mode, EGSB reactor exhibited insufficient COD removal efficiency, i.e., 50–60%. Therefore, UASB mode (without recirculation, 0.7 m/h upflow velocity) was used for 30 minutes in every 40 minutes cycle to increase the COD concentration in the sludge bed. As a result, an excellent process performance was shown. The COD removal efficiency increased from 65% to 91% and the reactor could maintain a good physical property of retained sludge (sludge concentration: 33.4 g VSS/L and SVI: 25 mL/g VSS). Furthermore, retained sludge possessed sufficient level of methanogenic activity at 20°C.

Changes of microbial characteristics of retained sludge during low-temperature operation of an EGSB reactor for low-strength wastewater treatment

2008 ◽  
Vol 57 (2) ◽  
pp. 277-281 ◽  
Author(s):  
K. Syutsubo ◽  
W. Yoochatchaval ◽  
H. Yoshida ◽  
K. Nishiyama ◽  
M. Okawara ◽  
...  
Keyword(s):  
Low Temperature ◽  
Granular Sludge ◽  
Methanogenic Bacteria ◽  
Cod Removal ◽  
Synthetic Wastewater ◽  
Methane Recovery ◽  
Efficient Treatment ◽  
Acetoclastic Methanogen ◽  
Microbial Characteristics ◽  
Microbial Characteristic

In this study, a lab scale EGSB reactor was operated for 400 days to investigate the influence of temperature-decrease on the microbial characteristic of retained sludge. The EGSB reactor was started-up at 15°C seeding with 20°C-grown granular sludge. The influent COD of synthetic wastewater was set at 0.6–0.8 gCOD/L. The process-temperature was stepwise reduced from 15°C to 5°C during 400 days operation. Decrease of temperature of the reactor from 15°C to 10°C caused the decline of COD removal efficiency. However, continuous operation of the EGSB reactor led the efficient treatment of wastewater (70% of COD removal, 50% of methane recovery) at 10°C. We confirmed that the both acetate-fed and hydrogen-fed methanogenic activities of retained sludge clearly increased under 15 to 20°C. Changes of microbial profiles of methanogenic bacteria were analyzed by 16S rDNA-targeted DGGE analysis and cloning. It shows that genus Methanospirillum as hydrogen-utilizing methanogen proliferated due to low temperature operation of the reactor. On the other hand, genus Methanosaeta presented in abundance as acetoclastic-methanogen throughout the experiment.

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