Nanoparticles in Methane Production from Anaerobic Digesters

2020 ◽  
pp. 202-232
Author(s):  
Efraín Reyes Cruz ◽  
Lilia Ernestina Montañez Hernández ◽  
Inty Omar Hernández De Lira ◽  
Nagamani Balagurusamy
Keyword(s):  
Methane Production ◽  
Anaerobic Digesters

scholarly journals Microbiota of anaerobic digesters in a full-scale wastewater treatment plant

2017 ◽  
Vol 43 (3) ◽  
pp. 53-60 ◽  
Author(s):  
Piotr Świątczak ◽  
Agnieszka Cydzik-Kwiatkowska ◽  
Paulina Rusanowska
Keyword(s):  
Microbial Community ◽  
Sewage Sludge ◽  
Methane Production ◽  
Treatment Plant ◽  
Full Scale ◽  
Successful Implementation ◽  
Anaerobic Digesters ◽  
Syntrophic Bacteria ◽  
The Stability ◽  
Microbial Groups

AbstractAnaerobic digestion is an important technology for the bio-based economy. The stability of the process is crucial for its successful implementation and depends on the structure and functional stability of the microbial community. In this study, the total microbial community was analyzed during mesophilic fermentation of sewage sludge in full-scale digesters.The digesters operated at 34–35°C, and a mixture of primary and excess sludge at a ratio of 2:1 was added to the digesters at 550 m3/d, for a sludge load of 0.054 m3/(m3·d). The amount and composition of biogas were determined. The microbial structure of the biomass from the digesters was investigated with use of next-generation sequencing.The percentage of methanogens in the biomass reached 21%, resulting in high quality biogas (over 61% methane content). The abundance of syntrophic bacteria was 4.47%, and stable methane production occurred at a Methanomicrobia to Synergistia ratio of 4.6:1.0. The two most numerous genera of methanogens (about 11% total) wereMethanosaetaandMethanolinea, indicating that, at the low substrate loading in the digester, the acetoclastic and hydrogenotrophic paths of methane production were equally important. The high abundance of the orderBacteroidetes, including the classCytophagia(11.6% of all sequences), indicated the high potential of the biomass for efficient degradation of lignocellulitic substances, and for degradation of protein and amino acids to acetate and ammonia.This study sheds light on the ecology of microbial groups that are involved in mesophilic fermentation in mature, stably-performing microbiota in full-scale reactors fed with sewage sludge under low substrate loading.

Application of Methanobrevibacter acididurans in anaerobic digestion

2004 ◽  
Vol 50 (6) ◽  
pp. 109-114 ◽  
Author(s):  
D.V. Savant ◽  
D.R. Ranade
Keyword(s):  
Fatty Acids ◽  
Anaerobic Digestion ◽  
Methane Production ◽  
Volatile Fatty Acids ◽  
Low Ph ◽  
Anaerobic Digesters ◽  
Hydrogenotrophic Methanogen ◽  
Distillery Wastewater ◽  
Acid Tolerant ◽  
Acidic Conditions

To operate anaerobic digesters successfully under acidic conditions, hydrogen utilizing methanogens which can grow efficiently at low pH and tolerate high volatile fatty acids (VFA) are desirable. An acid tolerant hydrogenotrophic methanogen viz. Methanobrevibacter acididurans isolated from slurry of an anaerobic digester running on alcohol distillery wastewater has been described earlier by this lab. This organism could grow optimally at pH 6.0. In the experiments reported herein, M. acididurans showed better methanogenesis under acidic conditions with high VFA, particularly acetate, than Methanobacterium bryantii, a common hydrogenotrophic inhabitant of anaerobic digesters. Addition of M. acididurans culture to digesting slurry of acidogenic as well as methanogenic digesters running on distillery wastewater showed increase in methane production and decrease in accumulation of volatile fatty acids. The results proved the feasibility of application of M. acididurans in anaerobic digesters.

scholarly journals Methods for the Evaluation of Industrial Mechanical Pretreatments before Anaerobic Digesters

Molecules ◽  
2020 ◽  
Vol 25 (4) ◽  
pp. 860 ◽  
Author(s):  
Helen Coarita Fernandez ◽  
Diana Amaya Ramirez ◽  
Ruben Teixeira Franco ◽  
Pierre Buffière ◽  
Rémy Bayard
Keyword(s):  
Particle Size ◽  
Rheological Properties ◽  
Production Rate ◽  
Methane Production ◽  
Water Retention Capacity ◽  
Retention Capacity ◽  
Anaerobic Digesters ◽  
Before And After ◽  
Methane Potential ◽  
Methane Production Rate

Different methods were tested to evaluate the performance of a pretreatment before anaerobic digestion. Besides conventional biochemical parameters, such as the biochemical methane potential (BMP), the methane production rate, or the extent of solubilization of organic compounds, methods for physical characterization were also developed in the present work. Criteria, such as the particle size distribution, the water retention capacity, and the rheological properties, were thus measured. These methods were tested on samples taken in two full-scale digesters operating with cattle manure as a substrate and using hammer mills. The comparison of samples taken before and after the pretreatment unit showed no significant improvement in the methane potential. However, the methane production rate increased by 15% and 26% for the two hammer mills, respectively. A relevant improvement of the rheological properties was also observed. This feature is likely correlated with the average reduction in particle size during the pretreatment operation, but these results needs confirmation in a wider range of systems.

Methane Production during Start-Up Phase of Mesophilic Semi-Continues Suspended Growth Anaerobic Digester

2010 ◽  
Vol 8 (1) ◽  
Author(s):  
Reem A Alrawi ◽  
Anees Ahmad ◽  
Norli I. ◽  
Mohd Omar A. K.
Keyword(s):  
Methane Production ◽  
Rumen Fluid ◽  
Granular Sludge ◽  
Continuous Stirred Tank Reactor ◽  
Anaerobic Digesters ◽  
Stabilization Phase ◽  
Start Up ◽  
Suspended Growth ◽  
Continuous Feeding ◽  
Continuous Stirred Tank

This study identified the effect and importance of the start-up period on methane production. Methane production was studied during the start-up period of semi-continuous stirred tank reactor (SCSTR) of anaerobic suspended growth under mesophilic conditions (37±3°C) with semi-continuous feeding. Two reactors were seeded with an inoculum of rumen fluid (5% and 10%) and mixed with anaerobic granular sludge (95% and 90%) as a substrate, respectively. The anaerobic digesters were filled up with 800 ml of these seeds during feeding phase. A supernatant of raw Palm oil mill effluent (POME) was fed in semi-continuous mode during the stabilization phase. The pH of the digesters was kept within the range of 7.2 -7.5 without any adjustment during this period. The effects of different concentration of seeding, MLVSS and COD (mg/L) on the quantity of produced methane during the start–up period were studied. The results showed that during the feeding phase methane content was 82.10% and 81.34% for both mixtures. But at the end of start-up period both reactors have the same percentage which is around 55%. Higher methane production occurred during the feeding phase for the second mixture. MLVSS and COD concentrations have a direct relationship with the methane obtained.

Combination of extremum-seeking algorithms with effective hydraulic handling of equalization tanks to control anaerobic digesters

2010 ◽  
Vol 61 (11) ◽  
pp. 2825-2834 ◽  
Author(s):  
J. Alferes ◽  
I. Irizar
Keyword(s):  
Methane Production ◽  
Wastewater Treatment Plants ◽  
The State ◽  
Extremum Seeking ◽  
Limit Set ◽  
Anaerobic Digesters ◽  
Set Point ◽  
Control Approach ◽  
Upper Limit ◽  
Equalization Tank

The benefits of upgrading extremum-seeking controllers with an effective exploitation of the buffer capacity of equalization tanks have been investigated and applied to anaerobic digesters. In this respect, a Fuzzy-based supervisory module that monitors the state of the equalization tank has been designed and built on top of an extremum-seeking algorithm in charge of automatically regulating the wastewater fed into the anaerobic digester. The extremum-seeking controller guarantees good disturbance rejection and methane production around an upper limit set-point. The on-top Fuzzy module optimizes the long-term methane production by modifying this upper limit set-point as a function of the state of the equalization tank. A systematic simulation study has been carried out to evaluate the performance of the proposed control solution. Thus, on the basis of existing simulation benchmarks for assessment of control strategies in wastewater treatment plants, a dedicated simulation protocol for anaerobic digesters has been defined and implemented. Simulation results have shown that, compared with manual operation, effluent quality and methane production improvements of 10–15% are achieved using the proposed control approach.

scholarly journals Inter-stage thermophilic aerobic digestion may increase organic matter removal from wastewater sludge without decreasing biogas production

2017 ◽  
Vol 77 (3) ◽  
pp. 721-726
Author(s):  
Sasha D. Hafner ◽  
Johan T. Madsen ◽  
Johanna M. Pedersen ◽  
Charlotte Rennuit
Keyword(s):  
Anaerobic Digestion ◽  
Methane Production ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Wastewater Sludge ◽  
Aerobic Digestion ◽  
Anaerobic Digesters ◽  
Stage System ◽  
Thermophilic Aerobic Digestion ◽  
Pre Treatment

Abstract Combining aerobic and anaerobic digestion in a two-stage system can improve the degradation of wastewater sludge over the use of either technology alone. But use of aerobic digestion as a pre-treatment before anaerobic digestion generally reduces methane production due to loss of substrate through oxidation. An inter-stage configuration may avoid this reduction in methane production. Here, we evaluated the use of thermophilic aerobic digestion (TAD) as an inter-stage treatment for wastewater sludge using laboratory-scale semi-continuous reactors. A single anaerobic digester was compared to an inter-stage system, where a thermophilic aerobic digester (55 °C) was used between two mesophilic anaerobic digesters (37 °C). Both systems had retention times of approximately 30 days, and the comparison was based on measurements made over 97 days. Results showed that the inter-stage system provided better sludge destruction (52% volatile solids (VS) removal vs. 40% for the single-stage system, 44% chemical oxygen demand (COD) removal vs. 34%) without a decrease in total biogas production (methane yield per g VS added was 0.22–0.24 L g−1 for both systems).

scholarly journals Assessing Methanogenic Archaeal Community in Full Scale Anaerobic Sludge Digester Systems in Dubai, United Arab Emirates

2018 ◽  
Vol 12 (1) ◽  
pp. 123-134 ◽  
Author(s):  
Munawwar A. Khan ◽  
Poojabahen G. Patel ◽  
Arpitha G. Ganesh ◽  
Naushad Rais ◽  
Sultan M. Faheem ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
United Arab Emirates ◽  
Methane Production ◽  
Archaeal Community ◽  
Full Scale ◽  
Anaerobic Sludge ◽  
Fish Analysis ◽  
Anaerobic Digesters ◽  
Archaeal Communities

Introduction:Anaerobic digestion for methane production comprises of an exceptionally diverse microbial consortium, a profound understanding about which is still constrained. In this study, the methanogenic archaeal communities in three full-scale anaerobic digesters of a Municipal Wastewater Treatment Plant were analyzed by Fluorescencein situhybridization and quantitative real-time Polymerase Chain Reaction (qPCR) technique.Methods & Materials:Fluorescencein situhybridization (FISH) was performed to detect and quantify the methanogenicArchaeain the sludge samples whereas qPCR was carried out to support the FISH analysis. Multiple probes targeting domain archaea, different orders and families of Archaea were used for the studies.Results and Discussion:In general, the aceticlastic organisms(Methanosarcinaceae & Methanosaetaceae)were more abundant than the hydrogenotrophic organisms(Methanobacteriales, Methanomicrobiales, Methanobacteriaceae & Methanococcales). Both FISH and qPCR indicated that familyMethanosaetaceaewas the most abundant suggesting that aceticlastic methanogenesis is probably the dominant methane production pathway in these digesters.Conclusion:Future work involving high-throughput sequencing methods and correlating archaeal communities with the main operational parameters of anaerobic digesters will help to obtain a better understanding of the dynamics of the methanogenic archaeal community in wastewater treatment plants in United Arab Emirates (UAE) which in turn would lead to improved performance of anaerobic sludge digesters.

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