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.

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.

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.

Acclimation of the trichloroethylene-degrading anaerobic granular sludge and the degradation characteristics in an upflow anaerobic sludge blanket reactor

2013 ◽  
Vol 69 (1) ◽  
pp. 120-127 ◽  
Author(s):  
Ying Zhang ◽  
Yang Liu ◽  
Miao Hu ◽  
Zhao Jiang
Keyword(s):  
Flow Reactor ◽  
Granular Sludge ◽  
Upflow Anaerobic Sludge Blanket ◽  
Volume Index ◽  
Synthetic Wastewater ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Methanogenic Activity ◽  
Operation Conditions ◽  
Anaerobic Sludge Blanket

The granulation process was examined in an 8 L laboratory upflow anaerobic sludge blanket (UASB) reactor using synthetic wastewater contained trichloroethylene (TCE). Glucose and lactate were used as primary substrates. The anaerobic bacteria biomass were acclimated and granulated by increasing the chemical oxygen demand (COD) and TCE loadings. Anaerobic sludge was acclimated successfully in 120 days in the anaerobic sludge acclimation appliance. Since start-up, the UASB was operated as a continuous-flow reactor under the following operation conditions: temperature of (35 ± 1)°C, pH ≈ 7.2, hydraulic retention time of 10 h, COD of 2.5 g L−1 and TCE loading rate from 50.5 to 252.3 mg · (L d)−1. The UASB reactor was started successfully. The sludge volume index was 13 mL g−1. The maximum specific methanogenic activity was 1.42 gCOD · (gVSS.d)−1. After 90 days, 85% of COD and 85% of TCE removal efficiencies were achieved. The TCE degrading granular sludge had an average diameter of 2.7 mm and total suspended solid of 52 g L−1. Anaerobic sludge adsorption of TCE reached adsorption equilibrium in 0.5 h, and in 1 h reached desorption equilibrium. Furthermore, cis-dichloroethylene and vinyl chloride were detected, which showed that the removal of TCE was caused by both adsorption and biodegradation but mainly by biodegradation.

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.

Removal of chlorinated phenols in upflow anaerobic sludge blanket reactors

1998 ◽  
Vol 38 (8-9) ◽  
pp. 359-367 ◽  
Author(s):  
Ronald L. Droste ◽  
Kevin J. Kennedy ◽  
Jingua Lu ◽  
Mercedes Lentz
Keyword(s):  
Acetic Acid ◽  
Upflow Anaerobic Sludge Blanket ◽  
Synthetic Wastewater ◽  
Anaerobic Sludge ◽  
Chlorinated Phenols ◽  
Reactor Performance ◽  
Chlorine Atoms ◽  
Toxic Agents ◽  
Anaerobic Sludge Blanket ◽  
Uasb Reactors

The dechlorination of chlorophenol (CP) compounds was investigated using upflow anaerobic sludge blanket reactors. A total of five trichlorophenols (TCPs) and a single dichlorophenol (DCP) were individually treated: 2,3,4-TCP; 2,3,5-TCP; 2,3,6-TCP; 2,4,5-TCP; 2,4,6-TCP; and 3,5-DCP. Synthetic wastewater composed of sucrose and acetic acid provided an alternate, readily biodegradable carbon source. Each chlorinated compound was concurrently fed to separate reactors. The parameters that were quantified include biogas composition, acetic acid concentration, COD, and VSS. The degree to which CPs were sorbed to the granular biomass in actively dechlorinating UASB reactors was found to be insignificant. CP compounds were able to be metabolized to mineral end products to a large extent at loadings where reactor performance was not impaired. Ortho chlorine atoms were most readily removed from CPs. CPs containing chlorine atoms in the para position were the most toxic agents with 2,4,5-TCP being the most toxic compound. Toxicity was reversible.

scholarly journals Anaerobic degradation of phenol in wastewater at ambient temperature

2004 ◽  
Vol 49 (1) ◽  
pp. 95-102 ◽  
Author(s):  
H.H.P. Fang ◽  
Y. Liu ◽  
S.Z. Ke ◽  
T. Zhang
Keyword(s):  
Ambient Temperature ◽  
Retention Time ◽  
Anaerobic Degradation ◽  
Hydraulic Retention Time ◽  
Phenol Degradation ◽  
Upflow Anaerobic Sludge Blanket ◽  
Synthetic Wastewater ◽  
Anaerobic Sludge ◽  
Anaerobic Sludge Blanket

Treating a synthetic wastewater containing phenol as the sole substrate at 26°C, an upflow anaerobic sludge blanket reactor was able to remove over 98% of phenol up to 1,260 mg/l in wastewater with 12 h of hydraulic retention time, corresponding to 6.0 g-COD/(l·day). Results showed that benzoate was the key intermediate of phenol degradation. Conversion of benzoate to methane was suppressed by the presence of phenol. Based on DNA cloning analysis, the sludge was composed of five groups of microorganisms. Desulfotomaculum and Clostridium were likely responsible for the conversion of phenol to benzoate, which was further degraded by Syntrophus to acetate and H2/CO2. Methanogens lastly converted acetate and H2/CO2 to methane. The role of epsilon-Proteobacteria was, however, unclear.

scholarly journals A Comparative Study of Biogas Production from Cattle Slaughterhouse Wastewater Using Conventional and Modified Upflow Anaerobic Sludge Blanket (UASB) Reactors

2019 ◽  
Vol 17 (1) ◽  
pp. 283 ◽  
Author(s):  
Mohammed Ali Musa ◽  
Syazwani Idrus ◽  
Mohd Razif Harun ◽  
Tuan Farhana Tuan Mohd Marzuki ◽  
Abdul Malek Abdul Wahab
Keyword(s):  
Loading Condition ◽  
Biogas Production ◽  
Bacterial Species ◽  
High Strength ◽  
Upflow Anaerobic Sludge Blanket ◽  
Synthetic Wastewater ◽  
Anaerobic Sludge ◽  
Slaughterhouse Wastewater ◽  
Anaerobic Sludge Blanket ◽  
Uasb Reactors

Cattle slaughterhouses generate wastewater that is rich in organic contaminant and nutrients, which is considered as high strength wastewater with a high potential for energy recovery. Work was undertaken to evaluate the efficiency of the 12 L laboratory scale conventional and a modified upflow anaerobic sludge blanket (UASB) reactors (conventional, R1 and modified, R2), for treatment of cattle slaughterhouse wastewater (CSWW) under mesophilic condition (35 ± 1 °C). Both reactors were acclimated with synthetic wastewater for 30 days, then continuous study with real CSWW proceeds. The reactors were subjected to the same loading condition of OLR, starting from 1.75, 3, 5 10, 14, and 16 g L−1d−1, corresponding to 3.5, 6, 10, 20, 28, and 32 g COD/L at constant hydraulic retention time (HRT) of 24 h. The performance of the R1 reactor drastically dropped at OLR 10 g L−1d−1, and this significantly affected the subsequent stages. The steady-state performance of the R2 reactor under the same loading condition as the R1 reactor revealed a high COD removal efficiency of 94% and biogas and methane productions were 27 L/d and 89%. The SMP was 0.21 LCH4/gCOD added, whereas the NH3-N alkalinity ratio stood at 651 mg/L and 0.2. SEM showed that the R2 reactor was dominated by Methanosarcina bacterial species, while the R1 reactor revealed a disturb sludge with insufficient microbial biomass.

Pemodelan Reaktor Hibrid Anaerob Pengolah Molasse Pada Pembebanan Organik Tinggi

2020 ◽  
Author(s):  
Gede H Cahyana
Keyword(s):  
Fluidized Bed ◽  
Fixed Bed ◽  
High Rate ◽  
Upflow Anaerobic Sludge Blanket ◽  
Anaerobic Sludge ◽  
Expanded Bed ◽  
Anaerobic Sludge Blanket

Telah dikembangkan reaktor anaerob kecepatan tinggi (high rate) yang merupakan modifikasi reaktor konvensional. Di antaranya berupa (bio)reaktor pertumbuhan tersuspensi (contoh: UASB, Upflow Anaerobic Sludge Blanket) dan reaktor pertumbuhan lekat (Fixed Bed atau Biofilter, Fluidized Bed, Expanded Bed, Rotating Biodisc dan Baffled Reactor). Kedua tipe reaktor di atas memiliki sejumlah kelebihan dan kekurangan. Untuk mengoptimalkan nilai positifnya (terutama untuk keperluan desain) maka reaktor tersebut, pada penelitian ini, disusun menjadi satu urutan yang disebut Reaktor Hibrid Anaerob (Rehan) yakni UASB di bawah dan AF di atasnya. Lebih lanjut, penelitian ini diharapkan dapat memberikan informasi tentang kinerja Rehan dalam mengolah air limbah (substrat) yang konsentrasi zat organiknya (COD) sangat tinggi dan suatu model matematika yang dapat mewakili reaktor tersebut.

The treatment of iron oxalate leach liquors in a UASB with sulfate reduction

1997 ◽  
Vol 36 (6-7) ◽  
pp. 383-390 ◽  
Author(s):  
J. E. Teer ◽  
D. J. Leak ◽  
A. W. L. Dudeney ◽  
A. Narayanan ◽  
D. C. Stuckey
Keyword(s):  
Bacterial Species ◽  
Upflow Anaerobic Sludge Blanket ◽  
Anaerobic Sludge ◽  
Desulfovibrio Vulgaris ◽  
Hydrogenotrophic Methanogenesis ◽  
Irreversible Effects ◽  
High Concentrations ◽  
A Minor ◽  
Anaerobic Sludge Blanket ◽  
Reducing Bacteria

The presence of small amounts of iron (>0.013% Fe) in sand creates problems in the manufacture of high quality glass. Removal by hot sulphuric acid is possible, but creates environmental problems, and is costly. Hence organic acids such as oxalic have been investigated since they are effective in removing iron, and can be degraded anaerobically. The aim of this work was to identify key intermediates in the anaerobic degradation of oxalate in an upflow anaerobic sludge blanket reactor (UASB) which was removing iron from solution in the sulphide form, and to determine the bacterial species involved. 2-bromoethanesulfonic acid (BES) and molybdenum were selected as suitable inhibitors for methanogenic and sulphate reducing bacteria (SRB) respectively. 40mM molybdenum was used to inhibit the SRB in a reactor with a 12hr HRT. Total SRB inhibition took place in 20 hrs, with a complete breakthrough of influent sulphate. The lack of an immediate oxalate breakthrough confirmed Desulfovibrio vulgaris subspecies oxamicus was not the predominant oxalate utilising species. Nevertheless, high concentrations of molybdenum were found to inhibit oxalate utilising bacteria in granular reactors but not in suspended population reactors; this observation was puzzling, and at present cannot be explained. Based on the intermediates identified, it was postulated that oxalate was degraded to formate by an oxalate utilising bacteria such as Oxalobacter formigenes, and the formate used by the SRBs to reduce sulphate. Acetate, as a minor intermediate, existed primarily as a source of cell carbon for oxalate utilising bacteria. Methanogenic inhibition identified that 62% of the CH4 in the reactor operated at 37°C originated from hydrogenotrophic methanogenesis, whilst this figure was 80% at 20°C. Possible irreversible effects were recorded with hydrogenotrophic methanogens.

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