The use of microsensors to study the role of the loading rate and surface velocity on the growth and the composition of nitrifying biofilms

2011 ◽  
Vol 64 (8) ◽  
pp. 1607-1613 ◽  
Author(s):  
B. C. Gonzalez ◽  
A. L. G. Spínola ◽  
A. W. Lamon ◽  
J. C. Araujo ◽  
J. R. Campos
Keyword(s):  
Loading Rate ◽  
Upflow Anaerobic Sludge Blanket ◽  
Surface Velocity ◽  
Synthetic Wastewater ◽  
Anaerobic Sludge ◽  
Ammonia Oxidizing Bacteria ◽  
Successful Operation ◽  
Bacterial Populations ◽  
Nitrite Oxidizing Bacteria ◽  
Anaerobic Sludge Blanket

The good composition and activity of biofilms are very important for successful operation and control of fixed-film biological reactors employed in liquid effluents treatment. During the last decade, microsensors have been applied to study microbial ecology. These sensors could provide information regarding the microbial activity concerning nitrification and denitrification that occur inside biofilms. Other techniques of molecular biology, such as fluorescence in situ hybridization (FISH), have also contributed to this matter because their application aids in the identification of the bacterial populations that compose the biofilms. The focus of this paper was to study the loading rate and surface velocity to promote the development of nitrifying biofilms in three distinct flow cells that were employed in the post treatment of a synthetic wastewater simulating the effluent from a UASB (Upflow Anaerobic Sludge Blanket) reactor. Using the FISH technique, it was found that the population of ammonia-oxidizing-bacteria was greater than that of nitrite-oxidizing-bacteria; this was also supported by the lower production of nitrate determined by physicochemical and microsensor analyses. It was verified that the loading rate and surface velocity that promoted the greatest nitrogen removal were 0.25 g N-amon·m−2biofilm·day−1 and 1 m h−1, respectively.

Start-Up Strategy to Achieve Excellent Efficiency of Degradation Acetate,Ethanol and Propionate in UASB

2011 ◽  
Vol 71-78 ◽  
pp. 2103-2106
Author(s):  
Ming Yue Zheng ◽  
Ming Xia Zheng ◽  
Kai Jun Wang ◽  
Hai Yan
Keyword(s):  
Loading Rate ◽  
Anaerobic Treatment ◽  
Upflow Anaerobic Sludge Blanket ◽  
Organic Loading Rate ◽  
Anaerobic Sludge ◽  
Organic Loading ◽  
Metabolic Intermediate ◽  
Loading Rates ◽  
Start Up ◽  
Anaerobic Sludge Blanket

The performance of upflow anaerobic sludge blanket (UASB) fed with three metabolic intermediate (acetate, ethanol, and propionate) respectively was studied. The degradation of metabolic intermediate were investigated to discuss the reason for propionate inhibition problem in anaerobic treatment. The hydraulic retention time (HRT) in the reactors started with 8.0h.The yield rate of biogas were 237ml/gCOD, 242ml/gCOD, 218ml/gCOD for acetate, ethanol and propionate, respectively when finishing start-up under OLR of 5.0 kgCOD/(m3·d) (HRT=9.6h).The HRT remained constant 9.6h,and the substrate concentration was gradually increased from 1,000 to 16,000mg/L as COD,and the organic loading rates(OLR) was from 3.0 to 40.0 kgCOD/(m3·d).The maximum propionate concentration was 41.6 gHPr-COD/L at the organic loading rate of 43.9 kgCOD/(m3·d) (HRT, 9.6h) as well as acetate and ethanol.

EFFECT OF COD LOADING RATE ON AN UPFLOW ANAEROBIC SLUDGE BLANKET REACTOR DURING ANAEROBIC DIGESTION OF PALM OIL MILL EFFLUENT WITH BUTYRATE / SUVARTOJAMO CHDS POVEIKIS PALMIŲ ALIEJAUS GAMYBINIŲ NUOTEKŲ SU BUTIRATU ANAEROBINIO PŪDYMO PLOKŠTELINIAME REAKTORIUJE METU

2012 ◽  
Vol 20 (4) ◽  
pp. 256-264 ◽  
Author(s):  
Anwar Ahmad ◽  
Rumana Ghufran ◽  
Zularisam Abd. Wahid
Keyword(s):  
Palm Oil ◽  
Methane Production ◽  
Loading Rate ◽  
Oxygen Demand ◽  
Palm Oil Mill Effluent ◽  
Upflow Anaerobic Sludge Blanket ◽  
Anaerobic Sludge ◽  
Loading Rates ◽  
Palm Oil Mill ◽  
Anaerobic Sludge Blanket

Palm oil Mill Effluent (POME) with concentrated butyrate was treated in a 4.5 l upflow anaerobic sludge blanket reactor (UASBR), run over a range of influent concentrations (16.5–46.0 g-COD l−1), chemical oxygen demand (COD) loading rates (1.5–11.5 g-CODl−1d−1) and 11–4 days hydraulic retention time (HRT) at 37 °C by maintaining pH between 6.5–7.5. The process consistently removed 97–99% of COD at loading rates up to 1.5–4.8 g-COD l−1d−1 by varying HRT (11–7.2 days). Butyrate is an important intermediate in the anaerobic degradation of organic matter. In sulphate-depleted environment, butyrate in POME (BOD/COD ratio of 0.5) is β-oxidised to acetate and hydrogen, by obligate proton reducers in syntrophic association with hydrogen utilizing methanogens. The conversion of acetate to methane appeared to be rate limiting step. Maximum biogas (20.17 ll−1d−1) and methane production (16.2 ll−1d−1) were obtained at COD loading rate of 4.80 gl−1d−1and HRT of 7.2 days. The biogas and methane production were higher in the presence of butyrate compared to control. The methane content of the biogas was in the range of 70–80% throughout the study while in control it was 60–65%. Finding of this study clearly indicates the successful treatment of POME with butyrate in UASBR. Santrauka Palmių aliejaus gamybinės nuotekos (POME) su koncentruotu butiratu buvo apdorotos 4,5 l talpos aukštyn tekančio aerobinio dumblo plokšteliniame reaktoriuje (UASBR). Nuotekos tekėjo įvairių koncentracijų (16,5–46,0 g – ChDS 1−1), cheminio deguonies suvartojimo (ChDS) normos (1,5–11,5 g – ChDS 1−1d.−1). Hidraulinio sulaikymo trukmė (HRT) nuo 11 iki 4 dienų, kai temperatūra 37 °C, pH palaikant 6,5–7,5. Vykstant procesui nuolat buvo pašalinama 97–99% ChD, kai tiekimo ir pakrovimo sparta 1,5–4,8 g – ChDS 1−1d.−1 kintant HRT(11–7,2 d.). Butiratas yra svarbus tarpininkas organinių medžiagų anaerobinio skilimo procese. Sulfatas iš aplinkos, butiratas iš POME (BDS/ChDS santykis 0,5) yra acetato ir vandenilio β oksidatoriai, priverčiantys protonų reducentus sintrofinės sąveikos su vandeniliu metu utilizuoti metanogenus. Acetato virtimas metanu pasirodė esąs greitį ribojantis veiksnys. Daugiausia biodujų (20,17 l 1−1 d.−1) ir metano (16,2 l 1−1 d.−1) susidarė tada, kai suvartojamo ChD tiekimo greitis buvo 4,80 g 1−1d.−1, o HRT – 7,2 dienos. Daugiau biodujų ir metano susidarė dalyvaujant butiratui, palyginti su kontroliniu pavyzdžiu. Biodujose metano kiekis tyrimo metu svyravo 70–80%, o kontroliniame buvo 60–65%. Šis tyrimas aiškiai parodė, kad POME su butiratu UASBreaktoriuje apdorojamas sėkmingai.

DEGRADATION OF STARCH PARTICULATES IN A HYBRID REACTOR

1994 ◽  
Vol 30 (4) ◽  
pp. 97-104 ◽  
Author(s):  
Herbert H. P. Fang ◽  
Tin-Sang Kwong
Keyword(s):  
Loading Rate ◽  
Oxygen Demand ◽  
Upflow Anaerobic Sludge Blanket ◽  
Hybrid Reactor ◽  
Anaerobic Sludge ◽  
Methanogenic Activity ◽  
Loading Rates ◽  
Granular Biomass ◽  
Abundant Supply ◽  
Anaerobic Sludge Blanket

The study was conducted over 265 days to study the feasibility of removing starch particulates from wastewater using an 8.5 L reactor which was a hybrid between the upflow anaerobic sludge blanket (UASB) and the anaerobic filter reactors. At pH 7.2-7.5 and 37°C, the reactor was effective for the removal of chemical oxygen demand (COD) from wastewater containing starch particulates equivalent to 5000 mglL of COD with 12 hours of retention time, corresponding to a loading rate of 10 g-COD/L.d. Despite their insoluble nature, the starch particulates did not cause noticeable adverse effeels on the granulation of biomass, probably due to its easy-to-biodegrade nature and the cautious startup strategy. About 5.8% of COD in wastewater remained in the effluent, 82.5% was converted to methane, and the remaining 11.7% was converted to granular biomass with an average sludge yield of 0.09 g-VSS/g-COD. The granules exhibited a layered microstructure. The methanogenic activity of the granular biomass was 0.86 g-methane-COD/g-VSS.d in the reactor, which was considerably lower than the 1.96 g-methane-COD/ g-VSS.d measured in serum vials with an abundant supply of substrate, suggesting that further increase of loading rates was possible for the hybrid reactor.

Pilot plant performance and model calibration of a sequencing batch air-lift reactor

1997 ◽  
Vol 35 (1) ◽  
pp. 121-128
Author(s):  
A. Brenner ◽  
N. Ben-Shushan ◽  
M. H. Siegel ◽  
J. C. Merchuk
Keyword(s):  
Optimization Technique ◽  
Plant Performance ◽  
Upflow Anaerobic Sludge Blanket ◽  
Synthetic Wastewater ◽  
Anaerobic Sludge ◽  
Model Parameters ◽  
Wastewater Treatment Process ◽  
Air Lift Reactor ◽  
Anaerobic Sludge Blanket ◽  
Air Lift

A sequencing batch wastewater treatment process was studied in a 200 L air-lift reactor (ALR), using a synthetic wastewater. A modification of the SBR process was introduced to exploit the ALR's geometric structure using an upflow anaerobic sludge blanket (UASB) mode of feeding. The mean COD removal efficiency of the process was extremely high. A study was made of the change in the filtered COD concentration in the reactor as a function of time during a cycle. A partial reduction in the COD was observed after the UASB Fill stage. Further removal of the residual COD was achieved within a very short time once air was supplied to the system. These phenomena required the inclusion of a biosorption-storage concept in the mathematical description of the system, in order to predict more precisely the COD transformations. The mathematical model parameters were evaluated experimentally and then calibrated with the aid of an optimization technique. Experimental results including COD, MLVSS, DO and OUR changes showed good agreement with model predictions.

THE PRODUCTION OF BIOHYDROGEN AND BIOMETHANE FROM CASSAVA WASTEWATER UNDER MESOPHILIC ANAEROBIC FERMENTATION BY USING UPFLOW ANAEROBIC SLUDGE BLANKET REACTORS (UASB)

2016 ◽  
Vol 78 (5-6) ◽  
Author(s):  
Patcharee Intanoo ◽  
Sumaeth Chavadej ◽  
Oijai Khongsumran
Keyword(s):  
Production Rate ◽  
Loading Rate ◽  
Anaerobic Fermentation ◽  
Oxygen Demand ◽  
H2 Production ◽  
Upflow Anaerobic Sludge Blanket ◽  
Anaerobic Sludge ◽  
Fixed Temperature ◽  
Cassava Wastewater ◽  
Anaerobic Sludge Blanket

The main objective was to separately generate biohydrogen (H2) and biomethane (CH4) with the cassava wastewater via the upflow anaerobic sludge blanket reactors (UASB) under the mesophilic temperature (37 ºC). For the first part, the production of H2, the controlled system was managed on the fixed temperature (37 º C) and pH (5.5) included the varied organic concentration in term of chemical oxygen demand (COD) loading rates. As the proper COD loading rate of 25 kg/m3 d, H2 and carbon dioxide (CO2) were mainly generated gases which provided the highest specific H2 production rate of 0.39 l H2/l d and the highest H2 yield of 39.83 l H2/kg COD removed. For the second part, the effluent liquid that generated from the stage of H2 production on COD loading rate of 25 kg/m3 d was fed to the UASB with the fixed temperature (37 °C) and no pH control. The highest specific CH4 production rate of 0.91 l CH4/l d and the highest CH4 yield of 115.23 l CH4/kg COD removed were shown on the proper COD loading rate of 8 kg/m3 d.  

Toxicity of Sodium and Potassium Ions on Performance of UASB System

2014 ◽  
Vol 953-954 ◽  
pp. 1105-1108 ◽  
Author(s):  
Seni Karnchanawong ◽  
Kraiwet Kabtum
Keyword(s):  
Biogas Production ◽  
Cod Removal ◽  
Upflow Anaerobic Sludge Blanket ◽  
Synthetic Wastewater ◽  
Organic Loading Rate ◽  
Anaerobic Sludge ◽  
Working Volume ◽  
Anaerobic Sludge Blanket ◽  
Uasb Reactors ◽  
Sodium And Potassium

The objective of this study was to investigate the toxicity of Na+and K+ions on performance of upflow anaerobic sludge blanket (UASB) system. Three laboratory-scale UASB reactors, 15.8 - l working volume, were employed with 1 reactor operated as control. They were loaded at organic loading rate (OLR) of 5 kg COD/(m3-d), treating synthetic wastewater with COD concentration ~ 5000 mg/l. Na+and K+ions were added in the range of 1010 - 7180 and 41 - 7320 mg/l, respectively. No toxicity was observed at influent Na+and K+concentrations up to 3340 and 2750 mg/l, respectively. Slight inhibitions on COD removal were founded at Na+and K+concentrations of 4610 and 3920 mg/l, respectively, but moderate effect on biogas production had occurred. When Na+and K+concentrations were increased to 7180 and 7320 mg/l, respectively, strong inhibitions were observed with COD removal dropped to 45.5 and 48.8 %, respectively. Ratios of biogas productions, as compared to the control reactor, were dropped to 0.31 and 0.32, respectively. Increasing cation concentrations had more detrimental effect on biogas production than COD removal.

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