Stability and activity of anaerobic sludge from UASB reactors treating sewage in subtropical regions

2006 ◽  
Vol 54 (2) ◽  
pp. 223-229 ◽  
Author(s):  
L. Seghezzo ◽  
C.M. Cuevas ◽  
A.P. Trupiano ◽  
R.G. Guerra ◽  
S.M. González ◽  
...  
Keyword(s):  
Rate Constant ◽  
Pilot Scale ◽  
Hydrolysis Rate ◽  
Anaerobic Sludge ◽  
Decay Rate Constant ◽  
Methanogenic Activity ◽  
Biological Sludge ◽  
Organic Matter Concentration ◽  
Aerobic Wastewater Treatment ◽  
Uasb Reactors

The production of small amounts of well-stabilized biological sludge is one of the main advantages of upflow anaerobic sludge bed (UASB) reactors over aerobic wastewater treatment systems. In this work, sludge produced in three pilot-scale UASB reactors used to treat sewage under subtropical conditions was assessed for both stability and specific methanogenic activity. Stability of primary sludge from settling tanks and digested sludge from conventional sludge digesters was also measured for comparison purposes. Kinetic parameters like the hydrolysis rate constant and the decay rate constant were calculated. High stability was observed in sludge from UASB reactors. Methanogenic activity in anaerobic sludges was relatively low, probably due to the low organic matter concentration in influent sewage. Knowledge on sludge growth rate, stability, and activity might be very useful to optimize sludge management activities in full-scale UASB reactors.

Granular biomass selection in a double-stage biogas collection UASB reactor: effects on SMA, abundance and diversity of the methanogenic population

2012 ◽  
Vol 66 (12) ◽  
pp. 2570-2577 ◽  
Author(s):  
J. O. Pereira ◽  
E. F. A. Mac Conell ◽  
S. Q. Silva ◽  
C. A. L. Chernicharo
Keyword(s):  
Denaturing Gradient Gel Electrophoresis ◽  
Cell Activity ◽  
Domestic Wastewater ◽  
Pilot Scale ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Methanogenic Activity ◽  
Gradient Gel Electrophoresis ◽  
Abundance And Diversity ◽  
Uasb Reactors

The present work aimed at investigating biomass selection in a pilot-scale double-stage biogas collection (DSBC) upflow anaerobic sludge bed (USAB) reactor treating domestic wastewater. Specific methanogenic activity (SMA) measurements and FISH countings were applied to sludge samples collected during 102 days of operation of the DSBC–UASB and of a control reactor. Results showed that both reactors presented similar SMA values in early stages of operation however the UASB–DSBC reactor showed much higher SMA after day 45, when the biomass was in granular stage. In terms of archaeal abundance, no statistical difference was observed between the reactors. Polymerase chain reaction–denaturing gradient gel electrophoresis (PCR–DGGE) revealed a similar composition of the archaeal communities in the two reactors and during the operational period, mainly constituted by Methanosaeta concilii. The results suggest that cell activity rather than archaeal abundance or diversity drive the methane production in the UASB reactors.

The effect of extreme temperatures (70–80°C) on the effluent quality and sludge characteristics of UASB reactors

1997 ◽  
Vol 36 (6-7) ◽  
pp. 325-332 ◽  
Author(s):  
Raghida Lepistö ◽  
Jukka Rintala
Keyword(s):  
Volatile Fatty Acids ◽  
Granular Sludge ◽  
Anaerobic Sludge ◽  
Methanogenic Activity ◽  
Sludge Characteristics ◽  
Effluent Quality ◽  
Start Up ◽  
Thermomechanical Pulping ◽  
Increasing Temperature ◽  
Uasb Reactors

The study focused on the effluent quality and sludge characteristics during the start-up and operation of extreme thermophilic (70 to 80°C) upflow anaerobic sludge bed (UASB) reactors, inoculated with mesophilic and thermophilic granular sludge and fed with acetate, volatile fatty acids (VFA), and thermomechanical pulping (TMP) whitewater. Low effluent quality and long start-up periods were observed during the start-up of the 70 to 76°C, VFA-fed UASB reactors inoculated with mesophilic granulae, while better effluent quality and considerably shorter start-up periods were observed when thermophilic (55/70°C) inocula were used. With VFA feed, a significant amount of acetate was removed at 70°C and even at 80°C, while propionate removal was negligible. With TMP whitewater feed, low VFA effluent concentration was obtained at 70°C. The volatile solids (VS) and the VS/total solids (TS) content of the sludge decreased significantly during the first 2–3 months of operation when mesophilic inocula were used. The initial specific methanogenic activity (ISMA) of the extreme thermophilic sludge decreased with increasing temperature and was slightly higher on glucose than on acetate. At 70 to 80°C, various rod-like bacteria were dispersed through the granulae in either individual or in low density micro colonies surrounded with a varying degree of precipitates.

Sludge Utilization and Reduction Experiences in the Pulp and Paper Industry

1992 ◽  
Vol 26 (9-11) ◽  
pp. 2105-2108 ◽  
Author(s):  
I. Öztürk ◽  
V. Eroglu ◽  
A. Bastürk
Keyword(s):  
Energy Requirement ◽  
Paper Industry ◽  
Paper Mill ◽  
Pilot Scale ◽  
Pulp And Paper ◽  
Upflow Anaerobic Sludge Blanket ◽  
Anaerobic Sludge ◽  
Pulp And Paper Mill ◽  
Biological Sludge ◽  
Study Results

This paper presents pilot-scale experiences on utilization of primary sludges from an integrated pulp and paper mill in the manufacturing of hardboard. The results have shown that the primary sludge added in 1/4 ratio yields the best result considering quality and operating aspects for the hardboard production. Lab-scale anaerobic treatability studies were carried out by an upflow anaerobic sludge blanket reactor (UASBR) with a volume of 10.351 using settled effluents from the related industry as the feed. Anaerobic treatability study results have shown that such an application prior to existing activated sludge system may provide 70 percent reduction in energy requirement for aeration and about 65 percent net reduction in excess biological sludge production.

Removal efficiency and methanogenic activity profiles in a pilot-scale UASB reactor treating settled sewage at moderate temperatures

2002 ◽  
Vol 45 (10) ◽  
pp. 243-248 ◽  
Author(s):  
L. Seghezzo ◽  
R.G. Guerra ◽  
S.M. González ◽  
A.P. Trupiano ◽  
M.E. Figueroa ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Retention Time ◽  
Sewage Treatment ◽  
Oxygen Demand ◽  
Granular Sludge ◽  
Pilot Scale ◽  
Cod Removal ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Methanogenic Activity

The performance of a sewage treatment system consisting of a settler followed by an Upflow Anaerobic Sludge Bed (UASB) reactor is described. Mean ambient and sewage temperature were 16.5 and 21.6°C, respectively. Total Chemical Oxygen Demand (CODt) concentration averaged 224.2 and 152.6 mg/L, for raw and settled sewage, respectively. The effluent concentration was 68.5 mgCODt/L. Total and suspended COD removal efficiencies of approximately 70 and 80%, respectively, have been observed in the system at a mean Hydraulic Retention Time (HRT) of 2 + 5 h. Maximum COD removal efficiency was achieved in the UASB reactor when upflow velocity (Vup) was 0.43 m/h (HRT = 6 h). Mean Specific Methanogenic Activity (SMA) and Volatile Suspended Solids (VSS) concentration in the granular sludge bed were 0.11 gCOD-CH4/gVSS.d and 30.0 gVSS/Lsludge, respectively. SMA was inversely related to VSS concentration, and both parameters varied along the sludge bed height. The Solids Retention Time (SRT) in the reactor was 450 days. Sludge characteristics have not been affected by changes of up to one month in Vup in the range 0.28–0.85 m/h (HRT 3–9 h). This system or two UASB reactors in series could be an alternative for sewage treatment under moderate temperature conditions.

The effect of operational conditions on the sludge specific methanogenic activity and sludge biodegradability

2009 ◽  
Vol 59 (9) ◽  
pp. 1847-1853 ◽  
Author(s):  
R. C. Leitão ◽  
S. T. Santaellla ◽  
A. C. van Haandel ◽  
G. Zeeman ◽  
G. Lettinga
Keyword(s):  
Municipal Wastewater ◽  
Pilot Scale ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Treatment Unit ◽  
Methanogenic Activity ◽  
Operational Conditions ◽  
Anaerobic Reactors ◽  
Specific Methanogenic Activity

The effects of hydraulic retention time (HRT) and influent COD concentration (CODInf) on Specific Methanogenic Activity (SMA) and the biodegradability of an anaerobic sludge need to be elucidated because of the discordant results available in literature. This information is important for the operation of anaerobic reactors and design of the sludge post-treatment unit. For this study, sludge samples obtained from eight pilot-scale Upflow Anaerobic Sludge Blanket (UASB) reactors were tested. The reactors were fed with municipal wastewater and operated with different sets of HRT and influent concentrations until the steady state was established. The results show that at a lower HRT, sludge with relatively higher SMA develops. A slight trend of declining SMA at increasing CODInf was found for reactors operated at longer HRTs; however, further experiments are necessary for more definitive conclusions. The sludge from reactors operated at longer HRTs and with lower CODInf resulted in lower biodegradability. Results also showed that it is ineffective to design a UASB reactor with a longer HRT to cope with organic shock loads.

Intermittent vs continuous operation of upflow anaerobic sludge bed reactors for dairy wastewater and related microbial changes

2006 ◽  
Vol 54 (2) ◽  
pp. 103-109 ◽  
Author(s):  
H. Nadais ◽  
I. Capela ◽  
L. Arroja
Keyword(s):  
Continuous Operation ◽  
Dairy Wastewater ◽  
Anaerobic Sludge ◽  
Methanogenic Activity ◽  
Beneficial Effects ◽  
Effluent Recirculation ◽  
Intermittent Operation ◽  
Acetoclastic Methanogenesis ◽  
Uasb Reactors ◽  
Stabilization Period

This work compares continuous vs intermittent UASB reactors inoculated with flocculent sludge for the treatment of dairy effluents. The effects of effluent recirculation on the performance of intermittent reactors were assessed as well as the differences in specific methanogenic activity (SMA) with different substrates for the biomass from continuous and intermittent UASB reactors. Compared to the continuous operation the intermittent operation resulted in higher methanization of the removed COD (64–78% and 65–88%, respectively) whilst the effluent recirculation presented beneficial effects when applied during the stabilization period and was clearly detrimental when applied during the feed period of the intermittent operation. The SMA tests showed that the intermittent operation causes a shift in the microbial populations towards a better adaptation for the degradation of complex substrates confirmed by the meaningfull contribution of methane production through a pathway other than acetoclastic methanogenesis observed in the biomass taken from intermittent UASB reactors.

The effect of operational conditions on the performance of UASB reactors for domestic wastewater treatment

2005 ◽  
Vol 52 (1-2) ◽  
pp. 299-305 ◽  
Author(s):  
R.C. Leitão ◽  
J.A. Silva-Filho ◽  
W. Sanders ◽  
A.C. van Haandel ◽  
G. Zeeman ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Municipal Wastewater ◽  
Domestic Wastewater ◽  
Pilot Scale ◽  
Cod Removal ◽  
Upflow Anaerobic Sludge Blanket ◽  
Anaerobic Sludge ◽  
Operational Conditions ◽  
Cod Removal Efficiency ◽  
Uasb Reactors

In this investigation, the performance of Upflow Anaerobic Sludge Blanket (UASB) reactors treating municipal wastewater was evaluated on the basis of: (i) COD removal efficiency, (ii) effluent variability, and (iii) pH stability. The experiments were performed using 8 pilot-scale UASB reactors (120 L) from which some of them were operated with different influent COD (CODInf ranging from 92 to 816 mg/L) and some at different hydraulic retention time (HRT ranging from 1 to 6 h). The results show that decreasing the CODInf, or lowering the HRT, leads to decreased efficiencies and increased effluent variability. During this experiment, the reactors could treat efficiently sewage with concentration as low as 200 mg COD/L. They could also be operated satisfactorily at an HRT as low as 2 hours, without problems of operational stability. The maximum COD removal efficiency can be achieved at CODInf exceeding 300 mg/L and HRT of 6 h.

Startup of thermophilic (55°C) UASB reactors using different mesophilic seed sludges

1996 ◽  
Vol 34 (5-6) ◽  
pp. 445-452 ◽  
Author(s):  
Herbert H. P. Fang ◽  
Ivan W. C. Lau
Keyword(s):  
Oxygen Demand ◽  
Upflow Anaerobic Sludge Blanket ◽  
Anaerobic Sludge ◽  
Methanogenic Activity ◽  
The Third ◽  
Uasb Granules ◽  
Thermophilic Condition ◽  
Anaerobic Sludge Blanket ◽  
The Impact ◽  
Uasb Reactors

Performances during startup of three 2.8-litre UASB (upflow anaerobic sludge blanket) reactors operated under thermophilic condition were investigated. All reactors were seeded with mesophilic sludges: one with flocculent digester sludge (Reactor-F), another with UASB granules (Reactor-G), and the third with disintegrated granules (Reactor-D). The reactors were operated in parallel at 55°C and 24 hours of retention time, using sucrose and milk as substrate at COD (chemical oxygen demand) loadings up to 10 g-COD/l·day. Immediately after temperature was step-increased from 37°C to 55°C, all reactors encountered sludge washout and deterioration of COD removal efficiency; however, the impact of temperature increase was more severe on Reactor-F. Sludge granulation took place in all reactors; first granules became noticeable after 45 days in Reactor-D, and after 90 days in Reactor-F. Reactor-G and Reactor-D were capable of removing 95% of soluble COD after 75 days, while Reactor-F after 110 days. Throughout this study, there was little difference in performance between Reactors G and D. The thermophilic granule were estimated to have a yield of 0.099 g-VSS/g-COD, and a methanogenic activity of 0.71-1.55 g-methane-COD/g-VSS·day, comparable to that of mesophilic granules.

Methanogenic Toxicity and Anaerobic Biodegradation of Chemical Products in Use in a Brewery

1999 ◽  
Vol 40 (8) ◽  
pp. 169-176 ◽  
Author(s):  
P. Nagel ◽  
A. Urtubia ◽  
G. Aroca ◽  
R. Chamy ◽  
M. Schiappacasse
Keyword(s):  
Wastewater Treatment Plants ◽  
Industrial Effluent ◽  
Methanogenic Bacteria ◽  
Effluent Treatment ◽  
Anaerobic Sludge ◽  
Compound A ◽  
Methanogenic Activity ◽  
Toxicity Effect ◽  
Chemical Products ◽  
Uasb Reactors

Brewery industry effluents, as any other industrial effluent, contain a number of chemical products that could be toxic in biological wastewater treatment plants. Most of these products come from clean in place (CIP) systems, i.e. detergents and disinfectant, and from lubrication systems. To evaluate the toxicity effect of these compounds on an anaerobic effluent treatment pilot plant, studies of methanogenic activity were carried out. The results showed that the synthetic lubricant evaluated had a high toxicity level, compared to the organic lubricant; the disinfectant showed inhibition to some extent. To decrease the toxicity effect, the recovery and reutilization of these chemicals are suggested. Experiments to study the feasibility of adapting anaerobic sludge to these compounds were carried out. Working with UASB reactors, the adaptation of the sludge takes place in the presence of the most toxic chemical products; certain inhibition was observed on methanogenic bacteria in the reactor where a disinfectant was added, even though there was sludge wash out. In general a decrease in the operational behaviour was observed after adding the compound, a new steady state was reached in absence of the toxic compounds, in terms of alkalinity ratio, removal of COD, methane production. The reactors were able to be recovered and to be adapted again.

scholarly journals Potencial bioquímico de metano de águas residuárias da ultrafiltração no processamento da acerola (Malpighia emarginata) verde

2020 ◽  
Vol 41 (2) ◽  
pp. 135
Author(s):  
Andreza Carla Lopes Andre ◽  
Miriam Cleide Cavalcante de Amorim ◽  
Kessia Caroline Dantas da Silva ◽  
Paula Tereza Souza e Silva
Keyword(s):  
Methane Production ◽  
Food Industry ◽  
Pilot Scale ◽  
Organic Load ◽  
Anaerobic Sludge ◽  
Biochemical Methane Potential ◽  
Decay Rate Constant ◽  
Malpighia Emarginata ◽  
Load Removal ◽  
Methane Potential

Ultrafiltration clarifies fruit juices, in the food industry, but generates retentive, recalcitrant wastewater, which, by its organic nature, may present a potential for biodegradation and methane production. This study aimed to evaluate the biochemical methane potential (BMP) in wastewater from the processing of unripe green acerola, obtaining the mass balance and the speed of organic load removal in COD terms. The BMP assays followed the German Guidelines VDI 4630, by applying three COD loads per liter of reactor vial (0,86 g CDOAplied L-1R, 1,5 g CDOAplied L-1R e 2,0 g CDOAplied L-1R), , in batches, inoculated with the anaerobic sludge from reactors treating domestic sewage, at 30 0C. The pH, COD, and methane production were evaluated every 48 hours. The biodegradability and the decay rate constant of the COD (Kd) were determined, thus obtaining the methanized COD, the COD for the formation of new cells, and the COD present in the wastewater, in the form of volatile acids. The best BMP was 0.100 L CH4 g -1 CDORemoved, the percentages of methanization were above 62 %, and the highest Kd occurred for the lowest load applied. The anaerobic digestion of the wastewater proved viable for in full-scale, with its application being suggested at a pilot scale.  

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