The effects of hydraulic and organic shock loads on the robustness of upflow anaerobic sludge blanket reactors treating sewage

2006 ◽  
Vol 54 (2) ◽  
pp. 49-55 ◽  
Author(s):  
R.C. Leitão ◽  
S.T. Santaellla ◽  
A.C. van Haandel ◽  
G. Zeeman ◽  
G. Lettinga
Keyword(s):  
Removal Efficiency ◽  
Cod Removal ◽  
Ph Stability ◽  
Upflow Anaerobic Sludge Blanket ◽  
Anaerobic Sludge ◽  
Hydraulic Shock ◽  
Treatment Unit ◽  
Shock Loads ◽  
Cod Removal Efficiency ◽  
Uasb Reactors

In this investigation, the robustness and stability of UASB reactors was evaluated on the basis of four indicators: (i) COD removal efficiency; (ii) effluent variability; (iii) pH stability; and (iv) recovery time. The experiments were carried out using six pilot-scale UASB reactors fed with domestic sewage and operated under different operational conditions. After establishment of a “steady-state”, organic and hydraulic shock loads (six times the loading rate during six hours) were imposed. The results show that the UASB reactors are robust systems with regards to COD removal efficiency and pH stability when exposed to shock loads. However, this reactor cannot attenuate the imposed fluctuation in the influent COD. A secondary treatment unit is needed to retain the expelled sludge occurring as a result of a hydraulic shock load, or prior to the shock, a sufficient amount of sludge needs to be discharged from the reactor.

Buoyant Filter Bio-Reactor (BFBR)–a novel anaerobic wastewater treatment unit

2008 ◽  
Vol 58 (2) ◽  
pp. 373-377
Author(s):  
Soosan J. Panicker ◽  
M. C. Philipose ◽  
Ajit Haridas
Keyword(s):  
Removal Efficiency ◽  
Treatment Plant ◽  
Cod Removal ◽  
Upflow Anaerobic Sludge Blanket ◽  
Organic Loading Rate ◽  
Anaerobic Sludge ◽  
Treatment Unit ◽  
Biogas Yield ◽  
Cod Removal Efficiency ◽  
Anaerobic Sludge Blanket

The Buoyant Filter Bio-Reactor (BFBR) is a novel and very efficient method for the treatment of complex wastewater. Sewage is a complex wastewater containing insoluble COD contributed by fat and proteins. The fat and proteins present in the domestic sewage cause operational problems and underperformance in the Upflow Anaerobic Sludge Blanket Reactor, used now for treating sewage anaerobically. The biogas yield from the BFBR is 0.36 m3/kg COD reduced and the methane content was about 70–80%. Production of methane by anaerobic digestion of organic waste had the benefit of lower energy costs for treatment and is thus environmentally beneficial to the society by providing a clean fuel from renewable feed stocks. The BFBR achieved a COD removal efficiency of 80–90% for an organic loading rate of 4.5 kg/m3/d at a hydraulic retention time of 3.25 hours. The effluent COD was less than 100 mg/l, thus saving on secondary treatment cost. No pretreatment like sedimentation was required for the influent to the BFBR. The BFBR can produce low turbidity effluent as in the activated sludge process (ASP). The land area required for the BFBR treatment plant is less when compared to ASP plant. Hence the problem of scarcity of land for the treatment plant is reduced. The total expenditure for erecting the unit was less than 50% as that of conventional ASP for the same COD removal efficiency including land cost.

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.

Thermophilic Anaerobic Treatment of Sulfate-Rich Pulp and Paper Integrate Process Water

1991 ◽  
Vol 24 (3-4) ◽  
pp. 149-160 ◽  
Author(s):  
J. Rintala ◽  
J. L. Sanz Martin ◽  
G. Lettinga
Keyword(s):  
Sulfate Reduction ◽  
Removal Efficiency ◽  
Anaerobic Treatment ◽  
Cod Removal ◽  
Process Water ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Cod Removal Efficiency ◽  
Uasb Reactors

Anaerobic treatment of sulfate - rich (COD/SO4 ratio 1.4-2.1) clarified Whitewater from a thermomechanical pulping (TMP) process was studied in three laboratory-scale upflow anaerobic sludge blanket (UASB) reactors at 55°C and in batch digesters at 55° and 65°C. Different seed materials were used in the UASB reactors. The highest COD removal efficiency (effluent sulfide stripped) achieved was approximately 65 % in the UASB reactors. About 55 % COD removal efficiency was obtained at a loading rate of about 41 kgCODm−3d−1 in the UASB reactor seeded with thermophilic sludge cultivated with volatile fatty acids (VFAs). The total sulfide present in the liquid phase after anaerobic treatment accounted for approximately 65-78 % and 15-61 % of the removed COD in the batch digesters and the UASB reactors, respectively. Sulfate reduction was almost complete in the batch digesters, whereas about 24-64 % of sulfate was reduced in the UASB reactors. Acetate utilization for sulfate reduction was apparent in the batch digesters, whereas that could not be demonstrated in the UASB reactors. Sulfate reduction in the UASB reactors was obviously substrate limited. In conclusion, thermophilic anaerobic treatment is an alternative for the treatment of warm sulfate rich TMP process water.

Effects of hydraulic shock loads on small on-site sewage treatment unit

1997 ◽  
Vol 35 (8) ◽  
pp. 145-152 ◽  
Author(s):  
T. Panswad ◽  
L. Komolmethee
Keyword(s):  
Removal Efficiency ◽  
Sewage Treatment ◽  
Septic Tank ◽  
Hydraulic Shock ◽  
Treatment Unit ◽  
Shock Loads ◽  
Retention Period ◽  
Intermittent Feeding ◽  
Continuous Feed ◽  
Filter Unit

This research was to determine the effects of hydraulic shock loads by intermittent feeding on the removal efficiency of a small prefabricated real-sized septic tank/anaerobic filter unit. Besides the ‘control’ 24-hour continuous runs the other twice a day feeding periods covered 16, 12 and 8 hours per day, with the tank's retention time varying from 22.5 to 90 hours. It was demonstrated that the variation of the hydraulic feeding patterns ranging from 24-hour continuous feed to 8 h per day intermittent feed did not affect the performance of the system much. The percentage of BOD reduction was decreased from 85 to 82 and 81 percent for the feed times of 24, 16 and 8 hours per day, respectively. The tank capacity played a relatively major role in determining the removal efficiency of the process. The efficiency of BOD and SS reduction dwindled from 82.2 to 68.9 and 56.0% with the corresponding reduction in tank sizes from 90 to 45 and 22.5 hours retention, respectively. In any event, the unit could not satisfactorily remove nutrients. A retention period of not less than 48 hours is recommended if the Thai effluent standards are to be met. Equations for predicting the BOD removal capability were also developed.

Effective Anaerobic Bio-Treatment of Fresh Leachate From Municipal Solid Waste Incineration Plant by Full-Scale Internal Circulation Reactor

2018 ◽  
Vol 141 (4) ◽  
Author(s):  
Tao Wang ◽  
Zhenxing Huang ◽  
Hongyan Ren ◽  
Hengfeng Miao ◽  
Minxing Zhao ◽  
...  
Keyword(s):  
Municipal Solid Waste ◽  
Solid Waste ◽  
Removal Efficiency ◽  
Full Scale ◽  
Cod Removal ◽  
Anaerobic Sludge ◽  
Internal Circulation ◽  
Biogas Yield ◽  
Cod Removal Efficiency ◽  
Effluent Recirculation

This study aimed to investigate the effectiveness of the full-scale internal circulation (IC) reactor in biodegrading of municipal solid waste (MSW) fresh leachate under mesophilic conditions, where the anaerobic process stability, biogas yield, and sludge granulation were intensively investigated. The effects of operational parameters on the influent organic loading rate (OLR), chemical oxygen demand (COD) removal efficiency, alkalinity (ALK), pH, volatile fatty acids (VFAs) accumulation, and effluent recirculation were also studied. The results showed that the reactor operated stably and effectively. The COD removal efficiency and biogas yield could be maintained at (92.8 ± 2.0)% and (0.47 ± 0.05) m3/kg CODremoval, respectively, with the influent OLR (24.5 ± 0.9) kg COD/(m3 d) and hydraulic retention time (HRT) 2.7d during the stable operation phase. Meanwhile, this study demonstrated that 1.5–3.0 m/h would be the optimal Vup for the reactor, corresponding to the effluent recirculation of 32.5–78.0 m3/h. Moreover, it was found that the content of extracellular polymeric substances (EPS) in the anaerobic sludge increased from 50.3 to 140.7 mg/g volatile suspended solids (VSS), and the sludge had good granular performance during the reactor operation.

Two examples of anaerobic pre-treatment of wastewater in the beverage industry

1997 ◽  
Vol 36 (2-3) ◽  
pp. 311-319 ◽  
Author(s):  
Ute Austermann-Haun ◽  
Karl-Heinz Rosenwinkel
Keyword(s):  
Removal Efficiency ◽  
Fruit Juice ◽  
Anaerobic Treatment ◽  
Full Scale ◽  
Cod Removal ◽  
Load Variations ◽  
Cod Removal Efficiency ◽  
Beverage Industry ◽  
Pre Treatment ◽  
Uasb Reactors

Two examples of full scale UASB-reactors in a fruit juice factory and a brewery are given. In both cases, the design was based on semi-technical tests. Although the wastewater concentrations are rather similar and move within a low range, the parts of the anaerobic treatment plants and their design are different. In both cases, the COD removal efficiency in the UASB-reactors is consistently above 80%. It becomes apparent that UASB-reactors are very suitable for industries with seasonal load variations. The co-fermentation of a kieselguhre-sludge-mixture was tested in lab-scale experiments. It became obvious that the pellet structure of the biomass gets lost. Furthermore, it is shown that the running expenses of anaerobic pre-treatment are very low, even when combined with an aerobic stage.

Characteristic of Granular Sludge Bed and Granular Sludge in Interior Diversion Expanded Granular Sludge Bed

2013 ◽  
Vol 726-731 ◽  
pp. 2813-2817
Author(s):  
Guang Li ◽  
Jing Li ◽  
Ke Sun
Keyword(s):  
Removal Efficiency ◽  
Granular Sludge ◽  
Gas Production ◽  
Cod Removal ◽  
Organic Loading Rate ◽  
Anaerobic Sludge ◽  
Cod Removal Efficiency ◽  
Seed Sludge ◽  
Bed Expansion

The interior diversion expanded granular sludge bed was concurrently operated for 140d to study the characteristic of the granular sludge bed. The influent COD concentration varied from 2000mg/L to 22300 mg/L, hydraulic retention time was maintained constant at 24 h and the organic loading rate was changed through a change in substrate concentration. The results showed that the reactor had great COD removal efficiency. When the MLSS was 23.1g/L, the influent COD was 18890mg/L, the COD removal efficiency was 80.4%; The interior diversion EGSB could greatly improve the role of gas-dynamic, when the liquid upflow velocity was 3.55m/h, the gas production was 5.96 L/d shows higher sludge bed expansion rate than 2.77 L/d about 9.5%. During the experimental, the anaerobic sludge has the following properties: the average sludge diameter was increased from 0.41mm to 1.66mm. Observed under the scanning electronic microscopy, we found that the sludge appeared obviously granulation, the bacteria amount and species are more than seed sludge after operation of 50d. It was found that rough surface of anaerobic sludge has clear figure with being covered by mucous lamina, with visible hole or cavity on surface.

Study on Granulation of Anaerobic Sludge in UASB Reactor Adding Cationic Polymer Treating Low Strength Wastewater at Room Temperature

2011 ◽  
Vol 71-78 ◽  
pp. 2974-2977 ◽  
Author(s):  
Zong Lian She ◽  
Jian Wu ◽  
Xiao Hui Fu ◽  
En Shi ◽  
Bao Shi Li ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Room Temperature ◽  
Control Experiment ◽  
Cationic Polymer ◽  
Cod Removal ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Cod Removal Efficiency ◽  
Low Strength ◽  
To Receive

Effect of cationic polymer on granulation and COD removal efficiency in lab scale UASB reactors was examined, treating low-strength wastewater (COD 300-500mg l-1) at room temperature. It was shown that cationic polymer was more effective for enhancing sludge granulation and COD removal efficiency as compared to the control experiment (without additives). After day 166 of operation, the amount of granules size above 0.5mm accounted for 32.1% of total sludge, higher than that of control experiment (19.3%). At 1.03 kg COD m-3 d-1 of OLR and 9.8 h of HRT, the effluent VFA had a maximum value of 168mg l-1 and 240mg l-1 in Reactor A and B respectively. The polymer-amended reactor took 36days to receive 1.44 kg COD m-3 d-1 of OLR at the 7.8 h of HRT, shorter than the control reactor (54days). The two reactors obtained above 80% in COD removal efficiency. It is shown that UASB reactor can also achieve higher COD removal treating low strength wastewater at room temperature.

Phenol degradation in horizontal-flow anaerobic immobilized biomass (HAIB) reactor under mesophilic conditions

2001 ◽  
Vol 44 (4) ◽  
pp. 167-174 ◽  
Author(s):  
R. M.L. Bolaños ◽  
M. B.A. Varesche ◽  
M. Zaiat ◽  
E. Foresti
Keyword(s):  
Removal Efficiency ◽  
Phenol Degradation ◽  
Oxygen Demand ◽  
Operating Conditions ◽  
Cod Removal ◽  
Horizontal Flow ◽  
Anaerobic Sludge ◽  
Cod Removal Efficiency ◽  
Immobilized Biomass ◽  
Potential Use

A bench-scale horizontal-flow anaerobic immobilized biomass (HAIB) reactor was assayed aiming to verify its potential use for phenol degradation. The HAIB reactor consisted of a bore-silicate tube (100 cm long; 5.04 cm diameter) filled with polyurethane foam matrices containing immobilized anaerobic sludge. Before being subjected to phenol, the reactor was fed with synthetic substrate at the influent chemical oxygen demand (COD) of 1,028 mg.l−1 achieving 98% of COD removal efficiency. Thereafter, phenol as the sole carbon source was added under step-increasing concentrations from 50 to 1,200 mg.l−1. Phenol degradation was evaluated by gas chromatographic analysis of influent and effluent samples. Process monitoring included determinations of pH, volatile acids, alkalinity and COD. The HAIB reactor was operated at a constant hydraulic detention time (HDT) of 12 hours. After 33 days with 50 mg/l of phenol in the influent, the reactor achieved 98% of COD removal efficiency. Successful phenol degradation (efficiency removal of 99%) occurred for influent concentrations of 100, 300, 600, 900 and 1,200 mg.l−1 after 148, 58, 47, 29 and 7 days, respectively. The predominance of Methanosaeta-like, rods and methanogenic cocci could be observed in all the operating conditions, besides the presence of phenol oxidizing microorganisms as irregular rods. The results indicate that phenol degradation at very high rates can be accomplished in HAIB reactors containing acclimatized biomass.

Removal Efficiency of Hazardous Material in Cyclohexanone Production Wastewater Applying Anaerobic Upflow Bed Filter

2010 ◽  
Vol 160-162 ◽  
pp. 1440-1444
Author(s):  
Dou Li ◽  
Dong Wei Li
Keyword(s):  
Removal Efficiency ◽  
Granular Sludge ◽  
Hazardous Materials ◽  
Cod Removal ◽  
The Self ◽  
Coagulation Necrosis ◽  
Anaerobic Sludge ◽  
Operational Parameters ◽  
Hazardous Material ◽  
Cod Removal Efficiency

The cyclohexanone production wastewater includes hazardous material such as cyclohexanone and cyclohexane which can harm the vessel of human body resulting in coagulation necrosis of viscera and brain. Our experiment choosed the cyclohexanone production wastewater to be investigated, and used the self-made anaerobic upflow bed filter (UBF) to deal with it. We try to find the optimal operational parameters which can make the degradation of hazardous materials maximizing. The COD removal efficiency was decreasing with the COD of influent’s increasing in starting stage, the shock load made the microbe in UBF can’t adapt the high VLR temporarily. In the running stage, the anaerobic sludge in UBF was incompact and the settleability of sludge was not very well. As the UBF running, the granular sludge shaped up greatly, the COD removal efficiency kept on 80%. The result showed that the UBF reactor was valid for hazardous material in cyclohexanone production wastewater.

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