scholarly journals Integrated sustainable anaerobic treatment for low strength wastewater

2011 ◽  
Author(s):  
S. I. Abou-Elela ◽  
M. E. Fawzy ◽  
M. El-Khateeb ◽  
W. Abdel-Halim
Keyword(s):  
Anaerobic Treatment ◽  
Low Strength

Low strength wastewater treatment using emerging anaerobic treatment processes

2019 ◽  
Author(s):  
◽  
Liyuan Hou
Keyword(s):  
Electron Transfer ◽  
Municipal Wastewater ◽  
Anaerobic Treatment ◽  
Methane Yield ◽  
Extracellular Electron Transfer ◽  
Anaerobic Sludge ◽  
Treatment Processes ◽  
Anodic Chamber ◽  
Specific Affinity ◽  
Low Strength

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] Anaerobic treatment is a promising and energy saving process for low-strength wastewater treatment. Roles of half saturation constant (Ks) and maximum specific growth rate (umax) in anaerobic treatment systems, however, are often overlooked. This study proposed to apply specific affinity (defined as umax/ Ks) as the key performance indicator of anaerobic processes treating low-strength wastewater. Furthermore, this study provided a new insight into the relationship between specific affinity and population of methanogens in an anaerobic membrane bioreactor (AnMBR) treating low-strength wastewater. High abundance of Methanosaeta (85.8% of total archaea) was linked to the high specific affinity (1.6 x 10[superscript -3] L/mg COD/d) in acclimated anaerobic sludge, resulting in low effluent chemical oxygen demand (COD) concentrations. Short hydraulic retention times (HRTs) are preferred for AnMBRs to treat low strength wastewater at a high volumetric organic loading rate with lower capital costs. However, short HRTs become a potential bottleneck in anaerobic treatment processes because of possible interspecies mass transfer limitations and membrane fouling in AnMBRs. Till now, little is known about how short HRTs would affect effluent water quality that is linked to the specific affinity of anaerobic sludge and their microbial community structures in AnMBRs. In current study, the overall performance, specific affinity of anaerobic sludge, and dynamics of community structures of an AnMBR treating synthetic municipal wastewater at decreasing HRTs (i.e., 24 h, 12 h, and 6 h) was investigated. A decrease in HRT resulted in sludge with high specific affinity. Correspondingly, Methanosaeta became the dominant methanogens in the AnMBR. Both the effluent water quality and methane yield were enhanced. Municipal wastewater contains complex organic constituents while multi-step biochemical processes are involved in anaerobic treatment processes. Two identical AnMBR were operated under decreasing HRTs (24 h, 12 h, and 6 h, respectively) treating low strength wastewater containing different substrate (acetate or glucose, respectively). As a result, microbial communities in the two AnMBRs diverged. The effluent quality and methane yield were enhanced in the acetate fed AnMBR while methane yield decreased in the glucose fed AnMBR as HRT decreased. Correspondingly, the abundance of Methanosaetaceae in the acetate fed AnMBR increased, but it decreased in the AnMBR fed with glucose. Interestingly, hydrogenotrophic methanogens have a higher proportion in the glucose fed AnMBR than in the acetate fed AnMBR. Overall, a minimum HRT higher than 6 h may be required to treat wastewater containing complex organic matter to ensure a successful operation. To treat the sulfate-containing low-strength wastewater, we proposed a newly designed anaerobic microbial fuel cell (MFC) system that could be used to produce electricity and remove sulfate simultaneously. A maximum voltage output of 129 mV was observed under the following feed conditions: that the ratio of lactate: sulfate was 60:20 and 0:10 in the anodic chamber and cathodic chamber, respectively. The decrease in the organic substrate/sulfate ratio in anodic chamber had a great effect on the electricity production, which could be resulted from an increasing DvH attaching on the electrode at a higher sulfate concertation contributes more electrons transfer. However, there was no significant electricity production at the ratio of two presumably because sulfate in the anodic chamber obtained all electrons produced by lactate without transferring to cathodic chamber since the stoichiometric ratio of lactate and sulfate is two. To our knowledge, this was the first time to show the electricity generation by using Desulfovibrio vulgaris Hildenborough (DvH) in such a MFC configuration. Electron microscopic analysis indicated that nanoscale filaments could enhance the extracellular electron transfer of DvH. DvH biofilm, which is necessary for extracellular electron transfer, suggesting that DvH has multiple direct electron transfer mechanisms. This could further benefit the application of DvH to enhance the power output and treat the real sulfate-containing low-strength wastewater.

The potentials of sub-mesophilic and/or psychrophilic anaerobic treatment of low strength wastewaters

1999 ◽  
pp. 221-234 ◽  
Author(s):  
G. Lettinga ◽  
S. Rebac ◽  
J. van Lier ◽  
G. Zeman
Keyword(s):  
Anaerobic Treatment ◽  
Low Strength

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 low-strength synthetic TCF effluents and biomass adhesion in fixed-bed systems

2008 ◽  
Vol 31 (6) ◽  
pp. 535-540 ◽  
Author(s):  
Anuska Mosquera-Corral ◽  
Angela Belmar ◽  
Jacqueline Decap ◽  
Katherine Sossa ◽  
Homero Urrutia ◽  
...  
Keyword(s):  
Fixed Bed ◽  
Anaerobic Treatment ◽  
Low Strength

Anaerobic treatment of low-strength municipal wastewater by a two-stage pilot plant under psychrophilic conditions

2008 ◽  
Vol 99 (15) ◽  
pp. 7051-7062 ◽  
Author(s):  
J.A. Álvarez ◽  
E. Armstrong ◽  
M. Gómez ◽  
M. Soto
Keyword(s):  
Pilot Plant ◽  
Municipal Wastewater ◽  
Anaerobic Treatment ◽  
Two Stage ◽  
Low Strength

Anaerobic Treatment of Low-Strength Domestic Wastewater Using an Anaerobic Expanded Bed Reactor

1998 ◽  
Vol 124 (7) ◽  
pp. 652-659 ◽  
Author(s):  
Anthony G. Collins ◽  
Thomas L. Theis ◽  
Srinivas Kilambi ◽  
Lin He ◽  
Spyros G. Pavlostathis
Keyword(s):  
Domestic Wastewater ◽  
Anaerobic Treatment ◽  
Expanded Bed ◽  
Low Strength

scholarly journals Influence of pH and the C/N ratio on the biogas production of wastewater

2019 ◽  
pp. 70-79 ◽  
Author(s):  
Alexandra Ceron-Vivas ◽  
Karen Tatiana Cáceres-Cáceres ◽  
Alejandro Rincón-Pérez ◽  
Alvaro Andrés Cajigas
Keyword(s):  
Biogas Production ◽  
Anaerobic Treatment ◽  
Methane Yield ◽  
Methanogenic Activity ◽  
Effluent Quality ◽  
Ph Values ◽  
Methane Production Rate ◽  
Low Strength ◽  
Influence Of Ph ◽  
Aerobic Sludge

Wastewater from institutions are considered with low strength and they may have a low C/N ratio and pH values higher than 7.0 units. In developing countries, anaerobic treatment for low strength wastewater is widely applied. However, COD removals and biogas production can be low due to inhibitions in the process. To improve the effluent quality, aerobic posttreatment has been used. The aim of this study was accessing the influence of pH and C/N ratio on methane yield of institutional wastewater, taking into account the aerobic sludge recirculation towards the anaerobic reactor. A factorial design 32 was used, evaluating different pH values: 6.9±0.1, 7.5±0.05 and 9.0±0.5; and C/N ratio: 4.9±0.2, 8.2±0.18 and 14.2±0.17. Biochemical methane (BMP) tests were performed using as inoculum a sludge with the hydrolytic, acidogenic and specific methanogenic activity of 2.79 gCOD/gVSS-d, 2.80 gCOD/gVSS-d and 0.14 gCODCH4/gVSS-d, respectively. Results indicating that with high C/N ratio, the methane yield increased. The maximum BMP was 318 L CH4/kgVSS with pH 7.5 and C/N ratio of 8.2±0.18; however, with the C/N ratio of 14.2±017 a major COD removal and methane production rate were observed.

The anaerobic treatment of low strength wastewaters in UASB and EGSB reactors

1997 ◽  
Vol 36 (6-7) ◽  
pp. 375-382 ◽  
Author(s):  
Mario T. Kato ◽  
Jim A. Field ◽  
Gatze Lettinga
Keyword(s):  
Detrimental Effect ◽  
Granular Sludge ◽  
Anaerobic Treatment ◽  
Organic Loading ◽  
Methanogenic Activity ◽  
Loading Rates ◽  
Treatment Performance ◽  
The Media ◽  
Low Strength ◽  
Uasb Reactors

The application of the UASB and EGSB reactors for the treatment of low strength wastewaters was investigated. The effect of dissolved oxygen on the methanogenic activity of granular sludges, the low substrate levels inside reactors and lower temperatures on the treatment performance were evaluated. The results showed that methanogens located in granular sludge have a high tolerance to oxygen. The concentration to cause 50% inhibition to methanogenic activity was between 7% and 41% oxygen in the head space of flasks, corresponding to 0.05 mg/l and 6 mg/l of DO prevailing in the media, respectively. The feasibility of UASB and EGSB reactors at 30°C was demonstrated. In UASB reactors, COD removal efficiencies exceeded 95% at organic loading rates up to 6.8 g COD/l.d and influent COD concentrations ranging from 422 to 722 mg/l, during the treatment of ethanol substrate. In EGSB reactors, efficiencies were above 80% at OLRs up to 12 g COD/l.d with COD as low as 100 to 200 mg/l. The studies confirmed that in practice DO does not constitute any detrimental effect on the reactor treatment performance. Lowering the temperature down to 15°C in EGSB reactors also showed that the potentials of anaerobic technology can be further explored in the treatment of dilute wastewaters.

ChemInform Abstract: Anaerobic Treatment of Low-Strength Wastewater by a Biofilm Reactor

ChemInform ◽  
2011 ◽  
Vol 42 (38) ◽  
pp. no-no
Author(s):  
Ioannis D. Manariotis ◽  
Sotirios G. Grigoropoulos ◽  
Yung-Tse Hung
Keyword(s):  
Anaerobic Treatment ◽  
Biofilm Reactor ◽  
Low Strength

Anaerobic Treatment of Low-Strength Brewery Wastewater in Expanded Granular Sludge Bed Reactor

1999 ◽  
Vol 76 (1) ◽  
pp. 15-32 ◽  
Author(s):  
Mario T. Kato ◽  
Salih Rebac ◽  
Gatze Lettinga
Keyword(s):  
Granular Sludge ◽  
Anaerobic Treatment ◽  
Brewery Wastewater ◽  
Low Strength
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