Pilot-plant study on anaerobic treatment of a lipid- and protein-rich food industrial wastewater by a thermophilic multi-staged UASB reactor

2002 ◽  
Vol 45 (10) ◽  
pp. 225-230 ◽  
Author(s):  
T. Tagawa ◽  
H. Takahashi ◽  
Y. Sekiguchi ◽  
A. Ohashi ◽  
H. Harada
Keyword(s):  
High Strength ◽  
Pilot Scale ◽  
Anaerobic Treatment ◽  
Cod Removal ◽  
Uasb Reactor ◽  
High Concentration ◽  
Methanogenic Activity ◽  
Ca Ions ◽  
Scale Experiment ◽  
Protein Rich

An on-site pilot-scale experiment was conducted to investigate the performance of a multi-staged UASB (MS-UASB) reactor by feeding with a food processing wastewater containing high strength of lipid and protein. The reactor was operated at a thermophilic condition (55°C) for a period of 600 days. The reactor finally achieved 50 kgCOD·m−3ád−1 with a soluble COD removal of 90% (based on the influent total COD versus the effluent filtered COD), while the overall COD removal (based on the effluent COD-total) was considerably unsatisfactory at around only 60–70%. The presence of high strength of lipid and protein along with high concentration of Mg and Ca ions in the raw wastewater caused a severe scum and/or insolubilized substance formation within the UASB sludge bed, resulting in hindering the contact efficiency between substrate and sludge. The replacement of active microbial granules in the sludge bed with the insolubilized protein and lipid brought about deterioration of sludge methanogenic activity.

On-site treatment of high-strength alcohol distillery wastewater by a pilot-scale thermophilic multi-staged UASB (MS-UASB) reactor

2006 ◽  
Vol 53 (3) ◽  
pp. 27-35 ◽  
Author(s):  
M. Yamada ◽  
M. Yamauchi ◽  
T. Suzuki ◽  
A. Ohashi ◽  
H. Harada
Keyword(s):  
Time Course ◽  
High Strength ◽  
Pilot Scale ◽  
Cod Removal ◽  
High Rate ◽  
Uasb Reactor ◽  
Reactor Performance ◽  
Methanogenic Activity ◽  
Working Volume ◽  
Distillery Wastewater

A pilot-scale multi-staged UASB (MS-UASB) reactor with a working volume of 2.5 m3 was operated for thermophilic (55°C) treatment of an alcohol distillery wastewater for a period of over 600 days. The reactor steadily achieved a super-high rate COD removal, that is, 60 kgCOD m−3 d−1 with over 80% COD removal. However, when higher organic loading rates were further imposed upon the reactor, that is, above 90 kgCOD m−3 d−1 for barely-based alcohol distillery wastewater (ADWW) and above 100 kgCOD m−3 d−1 for sweet potato-based ADWW, the reactor performance somewhat deteriorated to 60 and 70% COD removal, respectively. Methanogenic activity (MA) of the retained sludge in the thermophilic MS-UASB reactor was assessed along the time course of continuous run by serum-vial test using different substrates as a vial sole substrate. With the elapsed time of continuous run, hydrogen-utilizing MA, acetate-utilizing MA and propionate-fed MA increased at maximum of 13.2, 1.95 and 0.263 kgCOD kgVSS−1 d−1, respectively, indicating that propionate-fed MA attained only 1/50 of hydrogen-utilizing MA and 1/7 of acetate-utilizing MA. Since the ADWW applied herewith is a typical seasonal campaign wastewater, the influence of shut-down upon the decline in sludge MA was also investigated. Hydrogen-utilizing MA and acetate-utilizing MA decreased slightly by 3/4, during a month of non-feeding period, whereas propionate-fed MA were decreased significantly by 1/5. Relatively low values of propionate-fed MA and its vulnerability to adverse conditions suggests that the propionate degradation step is the most critical bottleneck of overall anaerobic degradation of organic matters under thermophilic condition.

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.

scholarly journals UASB Performance and Perspectives in Urban Wastewater Treatment at Sub-Mesophilic Operating Temperature

Water ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 115
Author(s):  
Daniele Cecconet ◽  
Arianna Callegari ◽  
Andrea G. Capodaglio
Keyword(s):  
Wastewater Treatment ◽  
Removal Efficiency ◽  
Biogas Production ◽  
Operating Temperature ◽  
Pilot Scale ◽  
Anaerobic Treatment ◽  
Cod Removal ◽  
Uasb Reactor ◽  
Urban Wastewater ◽  
Cod Removal Efficiency

UASBs present several advantages compared to conventional wastewater treatment processes, including relatively low construction cost facilities, low excess sludge production, plain operation and maintenance, energy generation in the form of biogas, robustness in terms of COD removal efficiency, pH stability, and recovery time. Although anaerobic treatment is possible at every temperature, colder climates lead to lower process performance and biogas production. These factors can be critical in determining the applicability and sustainability of this technology for the treatment of urban wastewater at low operating temperature. The purpose of this study is the performance evaluation of a pilot-scale (2.75 m3) UASB reactor for treatment of urban wastewater at sub-mesophilic temperature (25 °C), below the optimal range for the process, as related to biogas production and organic matter removal. The results show that, despite lower methane production and COD removal efficiency compared to operation under ideal conditions, a UASB can still achieve satisfactory performance, and although not sufficient to grant effluent discharge requirements, it may be used as a pretreatment step for carbon removal with some degree of energy recovery. Options for UASB pretreatment applications in municipal WWTPs are discussed.

Pilot-scale thermophilic anaerobic treatment of wastewaters from seasonal vegetable processing industry

1997 ◽  
Vol 36 (2-3) ◽  
pp. 279-285 ◽  
Author(s):  
J. A. Rintala ◽  
S. S. Lepistö
Keyword(s):  
Pilot Study ◽  
Food Industry ◽  
Buffer Capacity ◽  
Granular Sludge ◽  
Pilot Scale ◽  
Anaerobic Treatment ◽  
Cod Removal ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Loading Rates

Thermophilic anaerobic treatment of food industry wastewaters was studied using a 0.65 m3 upflow anaerobic sludge bed (UASB) reactor. The reactor was operated at 55°C and placed on the premises of a factory manufacturing deep-frozen goods from vegetables. The hot (>80-90°C) and concentrated (COD 14-79 g/l) wastewater streams, deriving from steam peeling and blanching of carrot and potato were used. The UASB reactor was inoculated with a small amount of granular sludge from a full-scale mesophilic UASB reactor. Prior to inoculation, the inoculum was acclimated to 55°C for 2 days. The reactor was fed with a mixture of wastewaters diluted to the desired COD. The reactor was started with loading rates of about 1.2 kgCOD/m3d. After the initial acidification of the process, apparently due to insufficient buffer capacity, the COD removal started to improve and reached 60% within 35 days of inoculation. At the end of the 70 days run, more than 80% COD removal was achieved with loading rates of about 4 kgCOD/m3d. The pilot-study run was limited due to the end of the seasonal production in the target factory. The results of the pilot study together with the results from the intensive laboratory studies suggest the feasibility of thermophilic anaerobic treatment for the studied wastewaters.

Inhibition of methanogenic activity of starch-degrading granules by aromatic pollutants

1997 ◽  
Vol 35 (8) ◽  
pp. 247-253 ◽  
Author(s):  
Herbert H. P. Fang ◽  
Ivan W. C. Lau ◽  
Denis W. C. Chung
Keyword(s):  
Chemical Industry ◽  
Functional Group ◽  
Anaerobic Treatment ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Aromatic Pollutants ◽  
Methanogenic Activity ◽  
Phenolic Pollutants ◽  
Ic50 Values

The effects of nine common aromatic pollutants from chemical industry on the bioactivity of anaerobic granules were examined. The granules were obtained from an upflow anaerobic sludge blanket (UASB) reactor treating wastewater containing colloidal starch. The specific methanogenic activities (SMA) of granules were measured at 37°C in serum vials using 3000 mg/l of colloidal starch as substrate, plus individual pollutants at various concentrations. The toxicity was expressed by the IR50 and IC50 values, i.e. the toxicant/biomass ratio and concentration at which levels the granules exhibited only 50% of their original bioactivities. Results showed that in general the granules exhibited mild resistance to toxicity of aromatic pollutants, probably due to the granules' layered microstructure. The toxicities, which were dependent on the nature of chemical functional group, of the aromatic pollutants were in the following descending order: cresols > phenol > hydroxyphenols/phthalate > benzoate. There was only marginal difference between the toxicity of the steric isomers. For the seven phenolic pollutants, the more hydrophobic the functional group the higher the toxicity. The granules' resistance to toxicity suggested the plausibility of anaerobic treatment of wastewater from the chemical industry.

Anaerobic treatment of landfill leachate by sulfate reduction

2000 ◽  
Vol 41 (3) ◽  
pp. 239-246 ◽  
Author(s):  
J.G. Henry ◽  
D. Prasad
Keyword(s):  
Landfill Leachate ◽  
High Surface ◽  
High Strength ◽  
Anaerobic Treatment ◽  
Cod Removal ◽  
Sulphate Reduction ◽  
High Rate ◽  
Organic Loading Rate ◽  
Filter Performance ◽  
Low Strength

The present study was conducted to investigate the effectiveness of the sulphate-reduction pathway in the anaerobic treatment of landfill leachate. The effects of several COD/SO4 ratios (keeping COD constant) and loadings on anaerobic filter performance were studied and compared with the results from anaerobic filters which followed the methanogenic pathway. Results indicated that the treatability of leachate by sulphate reducing bacteria (SRB) was dependent upon the leachate strength. With high strength leachate (COD=15000 mg/L) from the Keele Valley Landfill, it was found that at lower COD/SO4 ratios (≤1.6) toxic conditions developed in the system that were more inhibitory to the SRB than to the methane producing bacteria (MPB). As the COD/SO4 ratio increased, methanogenesis predominated. No predominance of SRB occurred at any COD/SO4 ratio with high strength leachate. The highest COD removal achieved was about 70% of which 20% was accomplished by the SRB at a COD/SO4 ratio of 1.6 and an organic loading rate (OLR) of 4 kg COD/m3.d. With low strength leachate (COD=1500-3300 mg/L) from the Brock West Landfill, and a COD/SO4 ratio <1, SRB became predominant. In these anaerobic filters in which SRB were predominant, the SRB reduced the COD as well as the MPB could. Sulphide inhibition did not take place at any loading in units treating low strength leachate. Consequently, both SRB and MPB should function at COD/SO4 ratios between 1 and 3. About 60% COD removal was achieved at a loading of 2.8 kg COD/m3.d and a COD/SO4 ratio of 1.0. However at a loading of 6 kg COD/m3.d only 27% COD removal was achieved, all of it through the sulphate-reduction pathway. These OLR values are comparable to those applied in systems where methanogenesis was dominant. It was also observed that once the methanogens were established in the units, it was not possible to displace them completely. However, where methanogenesis had not been previously established, it was found that sulphate-reduction could be the sole pathway for COD removal. From this study, it can be concluded that there is no advantage to the sulphate-reduction pathway in the anaerobic treatment of landfill leachate. The other options for increasing the loadings, i.e. the use of high surface/volume filter media (to achieve higher biomass concentrations) or high rate systems are likely to be more successful.

Anaerobic treatment of a medium strength industrial wastewater at low-temperature and short hydraulic retention time: a pilot-scale experience

2011 ◽  
Vol 64 (8) ◽  
pp. 1629-1635 ◽  
Author(s):  
M. Esparza Soto ◽  
C. Solís Morelos ◽  
J. J. Hernández Torres
Keyword(s):  
Low Temperature ◽  
Hydraulic Retention Time ◽  
Loading Rate ◽  
Pilot Scale ◽  
Anaerobic Treatment ◽  
Uasb Reactor ◽  
Organic Loading Rate ◽  
Organic Loading ◽  
Processing Industry ◽  
Industry Wastewater

The aim of this work was to evaluate the performance of a pilot-scale upflow anaerobic sludge blanket (UASB) reactor during the treatment of cereal-processing industry wastewater under low-temperature conditions (17 °C) for more than 300 days. The applied organic loading rate (OLRappl) was gradually increased from 4 to 6 and 8 kg CODsol/m3d by increasing the influent soluble chemical oxygen demand (CODsol), while keeping the hydraulic retention time constant (5.2 h). The removal efficiency was high (82 to 92%) and slightly decreased after increasing the influent CODsol and the OLRappl. The highest removed organic loading rate (OLRrem) was reached when the UASB reactor was operated at 8 kg CODsol/m3d and it was two times higher than that obtained for an OLRappl of 4 kg CODsol/m3d. Some disturbances were observed during the experimentation. The formation of biogas pockets in the sludge bed significantly complicated the biogas production quantification, but did not affect the reactor performance. The volatile fatty acids in the effluent were low, but increased as the OLRappl increased, which caused an increment of the effluent CODsol. Anaerobic treatment at low temperature was a good option for the biological pre-treatment of cereal processing industry wastewater.

Effect of trace metals on the anaerobic degradation of volatile fatty acids in molasses stillage

1995 ◽  
Vol 32 (12) ◽  
pp. 121-129 ◽  
Author(s):  
A. Espinosa ◽  
L. Rosas ◽  
K. Ilangovan ◽  
A. Noyola
Keyword(s):  
Trace Metals ◽  
Propionic Acid ◽  
Removal Efficiency ◽  
Volatile Fatty Acids ◽  
Biogas Production ◽  
Cod Removal ◽  
Uasb Reactor ◽  
Organic Load ◽  
Methanogenic Activity ◽  
Cod Removal Efficiency

A laboratory UASB reactor was fed with cane molasses stillage at organic loadings from 5 to 21.5 kg COD/m3 d. With an organic load of 17.4 kg COD/m3 d, an accumulation of VFA, principally propionic acid, was observed due to little bioavailability or lack of trace metals (Fe, Ni, Co and Mo). Associated to this, the performance of the UASB reactor was low (44% COD removal efficiency), with an alkalinity ratio above 0.4. The addition of Fe (100 mg/l), Ni (15 mg/l), Co (10 mg/l) and Mo (0.2 mg/l) to the influent reduced significantly the level of propionic acid (5291mg/l to 251 mg/l) and acetic acid (1100 mg/l to 158 mg/l). The COD removal efficiency increased from 44% to 58%, the biogas production from 10.7 to 14.8 l/d (NTP) and 0.085 to 0.32 g CH4-COD/g SSV d for specific sludge methanogenic activity with propionic acid as substrate. These improved results were obtained with high COD (68.9 g/l) and organic load (21.5 kg COD/m3 d).

ANAEROBIC TREATMENT OF DISTILLERY SLOPS IN THE CIRCUMSTANCES OF CENTRAL EUROPE

1994 ◽  
Vol 30 (3) ◽  
pp. 157-160
Author(s):  
Pavel Jenícek ◽  
Jana Zábranská ◽  
Michal Dohányos
Keyword(s):  
Central Europe ◽  
Raw Materials ◽  
Pilot Scale ◽  
Anaerobic Treatment ◽  
Gas Production ◽  
Raw Material ◽  
Uasb Reactor ◽  
Suitable Material ◽  
Large Production ◽  
Volumetric Loading

Anaerobic treatment of many kinds of slops is one of the most progressive ways for the reuse of this material. The special feature of Central Europe is that the largest proportion of ethanol is produced by fermentation, and the raw material in big distilleries is only sugar beet molasses. The consequence of this is a large production of slops in small regions, and as far as the quality of slops is concerned, a relatively high content of inert and nonbiodegradable organic compounds in comparison with other more valuable raw materials, such as grapes, fruits, cereals, potatoes, etc. A two-year operation of the pilot scale UASB reactor bas shown that molasses slops are a suitable material for anaerobic treatment The slops were diluted by other wastewaters from the distillery to a concentration of about 25 g.l‒1 COD and then treated in the pilot reactor at 32°C with the following average results: COD removal efficiency 78.8 %; volumetric loading rate 7.1 kg.m-3.d‒1; volumetric gas production 2.6 m3.m‒3.d‒1; specific gas production 0.47 m3.kg‒1. The results achieved confi11II that molasses slops are a source of energy. For example, Czech distilleries could potentially produce 12-17 million m3 of the valuable gas fuel per annum.

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.

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