scholarly journals Role of syntrophic microbial communities in high-rate methanogenic bioreactors

2012 ◽  
Vol 66 (2) ◽  
pp. 352-362 ◽  
Author(s):  
Alfons J. M. Stams ◽  
Diana Z. Sousa ◽  
Robbert Kleerebezem ◽  
Caroline M. Plugge
Keyword(s):  
Fatty Acid ◽  
Industrial Wastewater ◽  
Microbial Community Composition ◽  
Methanogenic Archaea ◽  
High Strength ◽  
Cost Effective ◽  
Anaerobic Treatment ◽  
High Rate ◽  
Degrading Bacteria

Anaerobic purification is a cost-effective way to treat high strength industrial wastewater. Through anaerobic treatment of wastewaters energy is conserved as methane, and less sludge is produced. For high-rate methanogenesis compact syntrophic communities of fatty acid-degrading bacteria and methanogenic archaea are essential. Here, we describe the microbiology of syntrophic communities in methanogenic reactor sludges and provide information on which microbiological factors are essential to obtain high volumetric methane production rates. Fatty-acid degrading bacteria have been isolated from bioreactor sludges, but also from other sources such as freshwater sediments. Despite the important role that fatty acid-degrading bacteria play in high-rate methanogenic bioreactors, their relative numbers are generally low. This finding indicates that the microbial community composition can be further optimized to achieve even higher rates.

Anaerobic digestion for sustainable development: a natural approach

2002 ◽  
Vol 45 (10) ◽  
pp. 321-328 ◽  
Author(s):  
H.J. Gijzen
Keyword(s):  
Industrial Wastewater ◽  
Systems Approach ◽  
Cost Effective ◽  
Anaerobic Treatment ◽  
High Rate ◽  
Natural Ecosystems ◽  
Natural Systems ◽  
Anaerobic Reactors ◽  
Rural And Urban ◽  
Pre Treatment

After the discovery of methane gas by Alessandro Volta in 1776, it took about 100 years before anaerobic processes for the treatment of wastewater and sludges were introduced. The development of high rate anaerobic digesters for the treatment of sewage and industrial wastewater took until the nineteen-seventies and for solid waste even till the nineteen-eighties. All digesters have in common that they apply natural anaerobic consortia of microorganisms for degradation and transformation processes. In view of this, it could be rewarding to evaluate the efficiency of natural ecosystems for their possible application. Examples of high rate anaerobic natural systems include the forestomach of ruminants and the hindgut of certain insects, such as termites and cockroaches. These “natural reactors” exhibit volumetric methane production rates as high as 35 l/l.d. The development of anaerobic reactors based on such natural anaerobic systems could produce eco-technologies for the effective management of a wide variety of solid wastes and industrial wastewater. Important limitations of anaerobic treatment of domestic sewage relate to the absence of nutrient and pathogen removal. A combination of anaerobic pre-treatment followed by photosynthetic post-treatment is proposed for the effective recovery of energy and nutrients from sewage. This eco-technology approach is based on the recognition that the main nutrient assimilating capacity is housed in photosynthetic plants. The proposed anaerobic-photosynthetic process is energy efficient, cost effective and applicable under a wide variety of rural and urban conditions. In conclusion: a natural systems approach towards waste management could generate affordable eco-technologies for effective treatment and resource recovery.

scholarly journals Methanogenic Microorganisms in Industrial Wastewater Anaerobic Treatment

Processes ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 1546
Author(s):  
Monika Vítězová ◽  
Anna Kohoutová ◽  
Tomáš Vítěz ◽  
Nikola Hanišáková ◽  
Ivan Kushkevych
Keyword(s):  
Wastewater Treatment ◽  
Industrial Wastewater ◽  
Methanogenic Archaea ◽  
High Strength ◽  
Anaerobic Treatment ◽  
Microbiome Composition ◽  
Anaerobic Wastewater Treatment ◽  
The Past ◽  
Anaerobic Reactors ◽  
Anaerobic Environment

Over the past decades, anaerobic biotechnology is commonly used for treating high-strength wastewaters from different industries. This biotechnology depends on interactions and co-operation between microorganisms in the anaerobic environment where many pollutants’ transformation to energy-rich biogas occurs. Properties of wastewater vary across industries and significantly affect microbiome composition in the anaerobic reactor. Methanogenic archaea play a crucial role during anaerobic wastewater treatment. The most abundant acetoclastic methanogens in the anaerobic reactors for industrial wastewater treatment are Methanosarcina sp. and Methanotrix sp. Hydrogenotrophic representatives of methanogens presented in the anaerobic reactors are characterized by a wide species diversity. Methanoculleus sp., Methanobacterium sp. and Methanospirillum sp. prevailed in this group. This work summarizes the relation of industrial wastewater composition and methanogen microbial communities present in different reactors treating these wastewaters.

Advances in high rate anaerobic treatment: staging of reactor systems

2001 ◽  
Vol 44 (8) ◽  
pp. 15-25 ◽  
Author(s):  
J.B. van Lier ◽  
F.P. van der Zee ◽  
N.C.G. Tan ◽  
S. Rebac ◽  
R. Kleerebezem
Keyword(s):  
Cost Effective ◽  
Anaerobic Treatment ◽  
High Rate ◽  
Extreme Conditions ◽  
Waste Streams ◽  
Textile Processing ◽  
Anaerobic Wastewater Treatment ◽  
Anaerobic Reactors ◽  
Wide Acceptance ◽  
Solids Retention

Anaerobic wastewater treatment (AnWT) is considered as the most cost-effective solution for organically polluted industrial waste streams. Particularly the development of high-rate systems, in which hydraulic retention times are uncoupled from solids retention times, has led to a world-wide acceptance of AnWT. In the last decade up to the present, the application potentials of AnWT are further explored. Research shows the feasibility of anaerobic reactors under extreme conditions, such as low and high temperatures. Also toxic and/or recalcitrant wastewaters, that were previously believed not to be suitable for anaerobic processes, are now effectively treated. The recent advances are made possible by adapting the conventional anaerobic high-rate concept to the more extreme conditions. Staged anaerobic reactor concepts show advantages under non-optimal temperature conditions as well as during the treatment of chemical wastewater. In other situations, a staged anaerobic - aerobic approach is required for biodegradation of specific pollutants, e.g. the removal of dyes from textile processing wastewaters. The current paper illustrates the benefits of reactor staging and the yet un-exploited potentials of high-rate AnWT.

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 simulated high-strength industrial wastewater containing chlorophenols

1994 ◽  
Vol 66 (1) ◽  
pp. 21-31 ◽  
Author(s):  
Joseph R. V. Flora ◽  
Makram T. Suidan ◽  
Alice M. Wuellner ◽  
Terrence K. Boyer
Keyword(s):  
Industrial Wastewater ◽  
High Strength ◽  
Anaerobic Treatment

Design of Pre-Acidification Reactors for the Anaerobic Treatment of Industrial Wastewaters

1994 ◽  
Vol 29 (9) ◽  
pp. 199-204 ◽  
Author(s):  
I. E. Alexiou ◽  
G. K. Anderson ◽  
L. M. Evison
Keyword(s):  
Industrial Wastewater ◽  
Volatile Fatty Acids ◽  
High Strength ◽  
Pilot Scale ◽  
Anaerobic Treatment ◽  
Coffee Production ◽  
Two Phase ◽  
Industrial Wastewaters ◽  
Wide Range ◽  
Pre Treatment

Two-phase anaerobic digestion has often been considered beneficial for the treatment of high strength industrial wastewaters, especially when the first phase is used as a pre-treatment system known as pre-acidification. Several applications in the field of industrial wastewater treatment have been reviewed in order to evaluate the advantages of the pre-acidification process and its effects on the methanogenic reactor. Although pre-acidification has obvious advantages, complete acidification may be detrimental to the efficiency of the overall process. The use of balancing tanks at full-scale has been common practice for the pre-acidification of a wide range of wastewaters yet no accepted design criteria for acidogenic reactors have been formulated and two-phase applications are generally based upon previous experience. The paper summarizes the results of a two year investigation into pre-acidification at both bench- and pilot-scale, presents the results of instant coffee production wastewaters and discusses a wide range of parameters which have been evaluated. Operating criteria will be discussed and guidelines for the design of pre-acidification reactors will be presented. Finally alternatives to using the total VFA (volatile fatty acids) concentrations for expressing the efficiency of acidogenesis will be introduced.

scholarly journals Up-Flow Anaerobic Sludge Blanket (UASB) Technology for Energy Recovery: A Review on State-of-the-Art and Recent Technological Advances

2020 ◽  
Vol 7 (2) ◽  
pp. 43 ◽  
Author(s):  
Matia Mainardis ◽  
Marco Buttazzoni ◽  
Daniele Goi
Keyword(s):  
Circular Economy ◽  
Microbial Community Composition ◽  
Anaerobic Treatment ◽  
High Rate ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Fatty Acid Production ◽  
Modeling Tools ◽  
Biogas Yield ◽  
Anaerobic Sludge Blanket

Up-flow anaerobic sludge blanket (UASB) reactor belongs to high-rate systems, able to perform anaerobic reaction at reduced hydraulic retention time, if compared to traditional digesters. In this review, the most recent advances in UASB reactor applications are critically summarized and discussed, with outline on the most critical aspects for further possible future developments. Beside traditional anaerobic treatment of soluble and biodegradable substrates, research is actually focusing on the treatment of refractory and slowly degradable matrices, thanks to an improved understanding of microbial community composition and reactor hydrodynamics, together with utilization of powerful modeling tools. Innovative approaches include the use of UASB reactor for nitrogen removal, as well as for hydrogen and volatile fatty acid production. Co-digestion of complementary substrates available in the same territory is being extensively studied to increase biogas yield and provide smooth continuous operations in a circular economy perspective. Particular importance is being given to decentralized treatment, able to provide electricity and heat to local users with possible integration with other renewable energies. Proper pre-treatment application increases biogas yield, while a successive post-treatment is needed to meet required effluent standards, also from a toxicological perspective. An increased full-scale application of UASB technology is desirable to achieve circular economy and sustainability scopes, with efficient biogas exploitation, fulfilling renewable energy targets and green-house gases emission reduction, in particular in tropical countries, where limited reactor heating is required.

Anaerobic Treatment of a High-Strength Industrial Waste Bearing Inhibitory Concentrations of 1,1,1-Trichloroethane

1991 ◽  
Vol 23 (7-9) ◽  
pp. 1385-1393 ◽  
Author(s):  
M. T. Suidan ◽  
A. M. Wuellner ◽  
T. K. Boyer
Keyword(s):  
Acetic Acid ◽  
Industrial Wastewater ◽  
High Strength ◽  
Anaerobic Treatment ◽  
Adsorptive Capacity ◽  
Phenol Removal ◽  
Feed Concentration ◽  
Successful Operation ◽  
Phenol Biodegradation ◽  
Better Than

A high-strength simulated industrial wastewater containing 5,900 mg/L of acetic acid, 3,000 mg/L of phenol, and 20-430 mg/L of 1,1,1-trichlorophenol (TCA) was successfully treated in an expanded-bed granular activated carbon (GAC) anaerobic reactor. Acetic acid and phenol removal efficiencies in this system were always better than 93 and 99 %, respectively, while TCA reduction was always better than 99.4 %. The adsorptive capacity of GAC was found to improve the performance efficiency of the system but was not necessary for the successful operation of the reactor. Acetate and phenol biodegradation was found to be inhibited by TCA, with a stronger effect observed on the methanogens. The treatment system was found to tolerate moderate fluctuations in the feed concentration of TCA.

scholarly journals Isolation and Characterization of Novel Bacteria Capable of Degrading 1,4-Dioxane in the Presence of Diverse Co-Occurring Compounds

2021 ◽  
Vol 9 (5) ◽  
pp. 887
Author(s):  
Tanmoy Roy Tusher ◽  
Takuya Shimizu ◽  
Chihiro Inoue ◽  
Mei-Fang Chien
Keyword(s):  
Industrial Wastewater ◽  
Cost Effective ◽  
Organic Load ◽  
Bacterial Strains ◽  
Gene Encoding ◽  
Initial Oxidation ◽  
Isolation And Characterization ◽  
Degrading Bacteria ◽  
Single Carbon Source ◽  
Group 5

Biodegradation is found to be a promising, cost-effective and eco-friendly option for the treatment of industrial wastewater contaminated by 1,4-dioxane (1,4-D), a highly stable synthetic chemical and probable human carcinogen. This study aimed to isolate, identify, and characterize metabolic 1,4-D-degrading bacteria from a stable 1,4-D-degrading microbial consortium. Three bacterial strains (designated as strains TS28, TS32, and TS43) capable of degrading 1,4-D as a sole carbon and energy source were isolated and identified as Gram-positive Pseudonocardia sp. (TS28) and Gram-negative Dokdonella sp. (TS32) and Afipia sp. (TS43). This study, for the first time, confirmed that the genus Dokdonella is involved in the biodegradation of 1,4-D. The results reveal that all of the isolated strains possess inducible 1,4-D-degrading enzymes and also confirm the presence of a gene encoding tetrahydrofuran/dioxane monooxygenase (thmA/dxmA) belonging to group 5 soluble di-iron monooxygenases (SDIMOs) in both genomic and plasmid DNA of each of the strains, which is possibly responsible for the initial oxidation of 1,4-D. Moreover, the isolated strains showed a broad substrate range and are capable of degrading 1,4-D in the presence of additional substrates, including easy-to-degrade compounds, 1,4-D biodegradation intermediates, structural analogs, and co-contaminants of 1,4-D. This indicates the potential of the isolated strains, especially strain TS32, in removing 1,4-D from contaminated industrial wastewater containing additional organic load. Additionally, the results will help to improve our understanding of how multiple 1,4-D-degraders stably co-exist and interact in the consortium, relying on a single carbon source (1,4-D) in order to develop an efficient biological 1,4-D treatment system.

Effect of Diluents on Post-Reaction Sintering of Silicon Nitride Ceramics

2007 ◽  
Vol 352 ◽  
pp. 185-188 ◽  
Author(s):  
Toru Wakihara ◽  
Masahiro Yabuki ◽  
Junichi Tatami ◽  
Katsutoshi Komeya ◽  
Takeshi Meguro ◽  
...  
Keyword(s):  
Bending Strength ◽  
Exothermic Reaction ◽  
High Strength ◽  
Cost Effective ◽  
Raw Material ◽  
Reaction Sintering ◽  
Oxygen Donor ◽  
Nitride Ceramics ◽  
Si3n4 Ceramics

Post-reaction sintering as a technique for the fabrication of Si3N4 ceramics has received much attention as a cost-effective process due to the use of cheap Si powder as a raw material. In this method, the rapid exothermic nitridation of Si results in local melting of Si to cause its agglomeration, which is expected to be a flaw after densification. Therefore, control of the exothermic reaction is needed to improve the reliability of post-reaction sintered Si3N4 ceramics. In this study, Si3N4 ceramics were fabricated by post-reaction sintering with Si3N4 or SiO2 powders in order to control the exothermic reaction. As a result, the microstructure and bending strength of Si3N4 ceramics was changed by adding these additives. In particular, the addition of SiO2 resulted in the high strength of Si3N4 ceramics. Consequently, it was found that Si3N4 and SiO2 particles played the role of diluents, and SiO2 was effective in post-reaction sintering as an oxygen donor.

Sign in / Sign up

Export Citation Format

Share Document