Influence of agitation rate on the performance of a stirred anaerobic sequencing batch reactor containing immobilized biomass

2001 ◽  
Vol 44 (4) ◽  
pp. 305-312 ◽  
Author(s):  
S. M. Ratusznei ◽  
J. A.D. Rodrigues ◽  
E. F.M. Camargo ◽  
M. Zaiat ◽  
W. Borzani
Keyword(s):  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Domestic Wastewater ◽  
Agitation Rate ◽  
Order Kinetic ◽  
Mechanical Agitation ◽  
Anaerobic Sequencing Batch Reactor ◽  
Substrate Removal ◽  
Order Kinetic Model ◽  
Immobilized Biomass

The present work reports on the influence of the mechanical agitation rates on the performance of a stirred anaerobic sequencing batch reactor containing immobilized biomass on polyurethane foam, as inert support, treating synthetic domestic wastewater. The reactor was operated at 30°C and an 8-hour cycle was used to treat approximately 0.5 L of the synthetic substrate with a COD concentration of nearly 500 mg/L. The studied agitation rates ranged from no agitation to 750 rpm. The system attained non-filtered substrate removal efficiency greater than 83% when agitation was employed. A very short start-up period and good solid retention could be observed. The use of agitation increased the efficiency of the reactor and enabled reduction of the total cycle time. An empirical equation and a first-order kinetic model are proposed to analyze the influence of agitation rates on the reactor's performance.

Operating feasibility of anaerobic whey treatment in a stirred sequencing batch reactor containing immobilized biomass

2003 ◽  
Vol 48 (6) ◽  
pp. 179-186 ◽  
Author(s):  
S.M. Ratusznei ◽  
J.A.D. Rodrigues ◽  
M. Zaiat
Keyword(s):  
Sequencing Batch Reactor ◽  
Cheese Whey ◽  
Batch Reactor ◽  
Oxygen Demand ◽  
Organic Load ◽  
Agitation Rate ◽  
Mechanical Agitation ◽  
Operating Stability ◽  
Immobilized Biomass ◽  
Startup Period

The scope of this work was to evaluate the operating feasibility of anaerobic whey treatment in a stirred sequencing batch reactor (ASBR) containing biomass immobilized on inert support. Assays were performed using 8-hour cycles and agitation rate of 200 rpm at 30 ± 1¡C, for treating cheese whey containing 500 to 4,000 mgCOD/L, which corresponded to a volumetric organic load (VOL) of 0.81 to 5.7 gCOD/L.d. Stability and high organic matter removal of about 96% were achieved at effluent concentration below 160 mgCOD/L for non filtered samples. Operating stability of the reactor was shown to be strongly dependent on the alkalinity supplementing strategy during the assay, especially during the startup period, where NaHCO3 supplementation was approximately 20Ð30% of the chemical oxygen demand (mgNaHCO3/mgCOD). After startup, alkalinity supplementation could be reduced down to 10% maintaining efficiency and stability. Moreover, proper homogenization of the system through mechanical agitation was also shown to be indispensable, especially with increasing organic load.

Substrate removal kinetics and performance assessment of a vermifilter bioreactor under organic shock load conditions

2016 ◽  
Vol 74 (5) ◽  
pp. 1177-1184 ◽  
Author(s):  
Tarun Kumar ◽  
K. S. Hari Prasad ◽  
Nitin Kumar Singh
Keyword(s):  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Pilot Scale ◽  
Shock Load ◽  
Order Kinetic ◽  
Shock Loads ◽  
Normal Loading ◽  
Substrate Removal ◽  
Order Kinetic Model ◽  
And Performance

In the present study, the effect of short-term organic shock loads (675, 799, 1,084 and 1,410 mg COD/L) on the treatment performance of a pilot-scale vermifilter (VF), employing an epigeic earthworm Eisenia fetida and treating synthetic domestic wastewater is investigated. The effect of organic shock loads on the performance and stability of vermifiltration reactor was evaluated to identify its feasibility in actual field conditions. Prior to the application of each organic shock load, normal loading conditions were maintained to achieve the pseudo steady state (PSS) conditions. The results showed satisfactory endurance against imposed organic shock loads with negligible reduction in chemical oxygen demand (COD) removals and it was almost similar to PSS condition with removal efficiencies of ∼ 66, 71, 67 and 68%, respectively. The experimental COD data fit well to first-order kinetic model, with a regression value of 0.95. At the end of all shock loads, the nutritional analysis of vermicompost obtained from the top layer of VF, showed increased concentration of total nitrogen (∼31 g/Kg) and total phosphorus (29 g/Kg). Besides, an augmented earthworm biomass, ∼23.2% on weight basis and ∼22% on number basis, was observed at the end of the study.

Stirred anaerobic sequencing batch reactor containing immobilized biomass: a behavior study when submitted to different fill times

2004 ◽  
Vol 49 (11-12) ◽  
pp. 311-318 ◽  
Author(s):  
A.C. Borges ◽  
R.R. Siman ◽  
J.A.D. Rodrigues ◽  
S.M. Ratusznei ◽  
M. Zaiat ◽  
...  
Keyword(s):  
Organic Matter ◽  
Polyurethane Foam ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Viscous Material ◽  
Filling Stage ◽  
Anaerobic Sequencing Batch Reactor ◽  
Behavior Study ◽  
Operation Stability ◽  
Immobilized Biomass

The effect of the filling stage on the behavior of a mechanically stirred anaerobic sequencing batch reactor containing biomass immobilized on 1 cm polyurethane foam cubes was investigated. The reactor was made of acrylic with a capacity of 6.3 L, treating per cycle 2.5 L synthetic low-strength wastewater with a concentration of 500 mgCOD/L, at 30 ± 1°C. Eight-hour cycles (tC) and agitation of 500 rpm were utilized. At the beginning of each cycle 60% of the wastewater volume was treated, sufficient to completely cover the bed. The remaining volume was added at different fill times (tF) of 10, 120, 240, 260 and 480 min. The results obtained showed that ratios of tF/tC ≤ 0.5 enabled organic matter removal higher than 75% and 70% for filtered and non-filtered samples, respectively. Ratios of tF/tC > 0.5, despite operation stability, resulted in loss of efficiency and formation of viscous material, similar to extra-cellular polymeric substances.

Influence of agitation rate on the performance of an anaerobic sequencing batch reactor containing granulated biomass treating low-strength wastewater

2003 ◽  
Vol 7 (2) ◽  
pp. 405-410 ◽  
Author(s):  
José Alberto Domingues Rodrigues ◽  
Suzana Maria Ratusznei ◽  
Eduardo Freitas Moraes de Camargo ◽  
Marcelo Zaiat
Keyword(s):  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Agitation Rate ◽  
Anaerobic Sequencing Batch Reactor ◽  
Low Strength
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