Potential pitfalls of FISH microscopy as assessment method for anaerobic digesters

AbstractIn the present work we investigated how the state of a biogas reactor impacts the enumeration of prokaryotic cells by fluorescencein situhybridisation (FISH). Therefore, the correlation between gas production and FISH hybridisation rates was analysed in different anaerobic digester sludges. High gasification activity coincided with high hybridisation rates. Low hybridisation rates were especially achieved with reactor samples subjected to long starvation periods showing low biogas production.Based on our findings we conclude that samples for FISH analysis should be fixed as soon as possible to prevent a loss of microbial activity resulting in lower FISH signals. Furthermore, the location of sampling is of importance, since samples from different fermenters within the same biogas plant also varied strongly in their FISH hybridisation rate. Our results indicate that FISH could be a useful method for assessing the metabolic state of microorganisms in anaerobic digester plants.

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Empirical Studies into Demand Based Reactor Sizing in Low-Cost Biogas Production for Domestic Utilization

FUOYE Journal of Engineering and Technology ◽

10.46792/fuoyejet.v3i1.172 ◽

2018 ◽

Vol 3 (1) ◽

Author(s):

Olayinka Omotosho ◽

Adebayo Oke

Keyword(s):

Rural Areas ◽

Biogas Production ◽

Low Cost ◽

Empirical Studies ◽

Total Yield ◽

Gas Production ◽

Management Of Resources ◽

Domestic Use ◽

Substrate Ratio ◽

Biogas Reactor

A low-cost biogas reactor incorporating a hydro-pressurizing and gas dispensing unit which was able to deliver biogas at a rate of 6.25 x 10-5m3/s and calculated pressure of 58.7N/m2 was designed and fabricated for the purpose of this study. The substrate loading intervals for the reactor were varied at 6, 7, 8, 12, 13, 17 and 33 days interval to determine which of the intervals gave the optimum yield in gas production. The fabricated unit had the highest average daily biogas production level and optimum total yield to substrate ratio at substrate feed interval of 13 days. Results obtained from the study were used to propose a biogas reactor sizing guideline for the low-cost biogas reactor design for domestic use. The proposed guideline would help in adequate deployment and management of resources for waste conversion and renewable energy production in rural areas.

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Velocity gradient as a tool to characterise the link between mixing and biogas production in anaerobic waste digesters

Water Science & Technology ◽

10.2166/wst.2013.206 ◽

2013 ◽

Vol 67 (12) ◽

pp. 2800-2806 ◽

Cited By ~ 25

Author(s):

R. Sindall ◽

J. Bridgeman ◽

C. Carliell-Marquet

Keyword(s):

Velocity Gradient ◽

Biogas Production ◽

Gas Production ◽

Valuable Contribution ◽

Anaerobic Digesters ◽

Mixing Speed ◽

Cfd Models ◽

Specific Effects ◽

Velocity Gradients ◽

Computational Fluid Dynamics Cfd

Whilst the importance of mixing in anaerobic digesters to enhance process performance and gas production is well recognised, the specific effects of mixing regime on biogas production are not clear. Here, the velocity gradient is used to demonstrate the importance of minimally mixed zones in a digester, with computational fluid dynamics (CFD) models indicating that 20–85% of a laboratory-scale digester experiences local velocity gradients of less than 10 s−1, dependent on mixing speed. Experimental results indicate that there is a threshold above which increased mixing speed (and hence velocity gradient) becomes counter-productive and biogas production falls. The effects of minimal mixing on digester microbiology are considered with the creation or destruction of localised pockets of high acetate concentration providing a possible explanation for the velocity gradient threshold. The identification of this threshold represents a valuable contribution to the understanding of the effects of mixing on gas production in anaerobic digesters.

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

The Open Microbiology Journal ◽

10.2174/1874285801812010123 ◽

2018 ◽

Vol 12 (1) ◽

pp. 123-134 ◽

Cited By ~ 3

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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Biogas Production from Swine Manure Co-Digestion with Hyacinth

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.953-954.304 ◽

2014 ◽

Vol 953-954 ◽

pp. 304-308

Author(s):

Sorrasak Thayai ◽

Supawat Vivanpatarakij

Keyword(s):

Carbon Dioxide ◽

Biogas Production ◽

Swine Manure ◽

Carbon Dioxide Production ◽

Gas Production ◽

Anaerobic Digesters ◽

Mixing Ratios ◽

Total Percentage ◽

Pig Farm ◽

Maximum Quantity

The suitable ratio between swine manure and hyacinth for biogas production was considered. From Ratchaburi Province, the swine manure and hyacinth were taken from the pig farm and natural canal, respectively. For this study, mixing ratios between swine manure with hyacinth are 0:100, 25:75, 50:50, 75:25 and 100:0, considered by dry basis. The anaerobic digesters were studied total mixing volume 300 ml in 500 ml volumetric flask on shaker. Total dry substrate is 2 g every ratio, swine manure and hyacinth. And microbial inoculum from pig farm is 3 g (dry basis). The experimental results showed the proportion of 0:100 illustrate the maximum quantity of biogas accumulated equal 243.48 ml. And the ratio of 100:0 shows the minimum cumulative biogas volume equal 33.60 ml. The analysis of the gas production, the blend of swine manure per hyacinth has the highest percentage of methane ratio is 0:100 (CH4=6.4%), and the lowest percentage is the ratio of 100:0 (CH4=0.5 %). For carbon dioxide production, the highest percentage of carbon dioxide is ratio of 0:100 (CO2=4.1 %) and the lowest is ratio 100:0 (CO2=0.9 %). Percentage of methane to compare with total percentage of methane and carbon dioxide has the highest percentage is the ratio of 25:75 (CH4=63.9 %), and the lowest percentage is the ratio of 100:0 (CH4=35.7 %). The highest to compare the lowest, percentage of methane per total percentage of methane and carbon dioxide is percentage of methane ratio 25:75 more than ratio 100:0 is 1.79.

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An experimental study on Bio-gas production by anaerobic digestion of RiceMill Wastewater (RMW)

Global NEST Journal ◽

10.30955/gnj.003442 ◽

2020 ◽

Vol 23 (1) ◽

pp. 35-42

Keyword(s):

Anaerobic Digestion ◽

Biogas Production ◽

Oxygen Demand ◽

Gas Production ◽

Anaerobic Digester ◽

Organic Loading Rate ◽

Anaerobic Sludge ◽

Working Volume ◽

Mesophilic Temperature ◽

Rice Mill Wastewater

<p>With the rising interest for sustainable power source and ecological security, anaerobic digestion of biogas technology has attracted considerable attention within the scientific researchers. This paper proposes a new research achievement on biogas production from Rice Mill Wastewater (RMW) with the utilization of anaerobic digester. An anaerobic digester is maintained with RMW and distillery anaerobic sludge at mesophilic temperature condition for 15 days as stabilization mode. After attaining stabilization stage, studies continued to examine the effect of Organic Loading Rate (OLR) and Hydraulic Retention Time (HRT) on the mesophilic anaerobic digestion of RMW. The OLR of the anaerobic reactor increased stepwise from 0.25 to 3.91 Kg COD/m3/dayand HRT ranged from 1 to 32.0 days. The total chemical oxygen demand (TCOD) utilized was higher than 75% and the CH4 percentage of the biogas was 62.00-63.00% for the OLRs studied. The efficient working volume of the digester is preserved as 25% of distillery anaerobic sludge and 75% of rice mill wastewater, loaded at Mesophilic temperature conditions for study purpose. By changing the conditions of OLR and HRT, biogas production, methane yield and percentage of COD reduction is examined. An anaerobic sludge is utilized as a seeding material to biodegrade the organic pollutants present in the wastewater. It will enhance the biological treatment of effluent with anaerobic sludge in a continuous mode of activity.The result showed that the proposed analysis obtains more biogas production with reduced COD when compared with existing approaches.</p>

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In Situ Acoustic Treatment of Anaerobic Digesters to Improve Biogas Yields

Environments ◽

10.3390/environments7020011 ◽

2020 ◽

Vol 7 (2) ◽

pp. 11 ◽

Cited By ~ 3

Author(s):

John Loughrin ◽

Stacy Antle ◽

Karamat Sistani ◽

Nanh Lovanh

Keyword(s):

Microbial Growth ◽

Vibrational Energy ◽

Biogas Production ◽

Acoustic Cavitation ◽

Pilot Scale ◽

Broadband Noise ◽

Anaerobic Digesters ◽

Acoustic Treatment

Sound has the potential to increase biogas yields and enhance wastewater degradation in anaerobic digesters. To assess this potential, two pilot-scale digestion systems were operated, with one exposed to sound at less than 10 kHz and with one acting as a control. Sounds used were sine waves, broadband noise, and orchestral compositions. Weekly biogas production from sound-treated digesters was 18,900 L, more than twice that of the control digester. The sound-treated digesters were primarily exposed to orchestral compositions, because this made cavitational events easier to identify and because harmonic and amplitude shifts in music seem to induce more cavitation. Background recordings from the sound-treated digester were louder and had more cavitational events than those of the control digester, which we ascribe to enhanced microbial growth and the resulting accelerated sludge breakdown. Acoustic cavitation, vibrational energy imparted to wastewater and sludge, and mixing due to a release of bubbles from the sludge may all act in concert to accelerate wastewater degradation and boost biogas production.

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Fatigue Assessment of Installed Thermowells: Fatigue Stress Evaluation Based on In-Situ Vibration Measurements and Dedicated Models

Volume 3: Design and Analysis ◽

10.1115/pvp2020-21296 ◽

2020 ◽

Author(s):

Pieter van Beek

Keyword(s):

Resonance Condition ◽

Flow Direction ◽

Assessment Method ◽

Gas Production ◽

Fe Model ◽

Gas Temperature ◽

Vibration Measurements ◽

Fatigue Assessment ◽

Fatigue Stress

Abstract For measurement of the gas temperature inside process piping, temperature sensors are installed in a thermowell. In most cases these cylindrical thermowells are installed perpendicular to the flow direction. Declining pressures of many aging oil & gas assets results in higher gas velocities. This will increase the so-called Strouhal frequency and amplitude of the dynamic forcing at the thermowell. If the frequency of this force coincides with the installed resonance frequency of the thermowell, this can lead to fatigue failure. The design of thermowells is comprehensively described in ASME PTC19.3 TW Code. In a recent version the excitation of the so-called in-line resonance condition was introduced, which already occurs at half the flow velocity of the original transverse resonance condition. As a result, many already installed thermowells do not pass the so-called ‘frequency criterion’ anymore. However, when all other criteria in the ASME Code are passed, the thermowell may operate at higher flow velocities, only if the fatigue stress remains acceptable. When calculating the fatigue stress with the tools as provided in the Code, in many cases this will lead to prediction of unacceptable fatigue stresses. Therefore, here a more detailed fatigue assessment method has been developed. It consists of in-situ vibration measurements at the tip of the thermowell and a numerical evaluation with a detailed FE model of the installed thermowell. With this approach the fatigue stress is then calculated and judged against a fatigue limit. In the meanwhile, this detailed assessment method has been successfully applied to numerous high pressure, gas filled installations. In most cases this led to acceptable fatigue stresses and preservation of the desired gas production profiles.

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Hydrothermal Pretreatment of Rice Straw with Alkaline Addition for Enhancing Biogas Production in Semicontinuous Anaerobic Digester

Journal of Physics Conference Series ◽

10.1088/1742-6596/2117/1/012034 ◽

2021 ◽

Vol 2117 (1) ◽

pp. 012034

Author(s):

A Sato ◽

A Widjaja ◽

Soeprijanto

Keyword(s):

Production Process ◽

Hydrothermal Treatment ◽

Rice Straw ◽

Biogas Production ◽

Anaerobic Digester ◽

Hydrothermal Pretreatment ◽

Organic Degradation ◽

Anaerobic Digesters

Abstract This study presents the results of hydrothermal pretreatment of rice straw on its ability to improve the biogas production process in anaerobic digesters. Hydrothermal treatment on rice straw biomass was carried out with the addition of 0%, 3% and 5% NaOH (w/w rice straw) for one hour at a temperature of 140 °C. This study showed that hydrothermal and alkaline hydrothermal pretreatments were able to increase organic degradation of rice straw as indicated by an increase in the dissolution of lignin and hemicellulose from rice straw. Temperature and NaOH worked synergistically to dissolve lignocellulose in the hydrothermal pretreatment process. In the semicontinuous digester fed with pretreated rice straw, NaOH content in the pretreatment stage was found to give significant effect in enhancing biogas production. Average daily biogas production by the untreated rice straw, hydrothermal pretreated without NaOH addition, hydrothermally treated rice straw with 3% NaOH and 5% NaOH was 23.9, 57.1, 95.8 and 108.8 L/kg rice straw, respectively.

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Jacobsen syndrome and neonatal bleeding: report on two unrelated patients

Italian Journal of Pediatrics ◽

10.1186/s13052-021-01108-2 ◽

2021 ◽

Vol 47 (1) ◽

Author(s):

Gregorio Serra ◽

Luigi Memo ◽

Vincenzo Antona ◽

Giovanni Corsello ◽

Valentina Favero ◽

...

Keyword(s):

Developmental Delay ◽

De Novo ◽

Comparative Genomic ◽

Fish Analysis ◽

Variable Degree ◽

Jacobsen Syndrome ◽

Contiguous Gene ◽

Clinical Consequences ◽

11Q Deletion

Abstract Introduction In 1973, Petrea Jacobsen described the first patient showing dysmorphic features, developmental delay and congenital heart disease (atrial and ventricular septal defect) associated to a 11q deletion, inherited from the father. Since then, more than 200 patients have been reported, and the chromosomal critical region responsible for this contiguous gene disorder has been identified. Patients’ presentation We report on two unrelated newborns observed in Italy affected by Jacobsen syndrome (JBS, also known as 11q23 deletion). Both patients presented prenatal and postnatal bleeding, growth and developmental delay, craniofacial dysmorphisms, multiple congenital anomalies, and pancytopenia of variable degree. Array comparative genomic hybridization (aCGH) identified a terminal deletion at 11q24.1-q25 of 12.5 Mb and 11 Mb, in Patient 1 and 2, respectively. Fluorescent in situ hybridization (FISH) analysis of the parents documented a de novo origin of the deletion for Patient 1; parents of Patient 2 refused further genetic investigations. Conclusions Present newborns show the full phenotype of JBS including thrombocytopenia, according to their wide 11q deletion size. Bleeding was particularly severe in one of them, leading to a cerebral hemorrhage. Our report highlights the relevance of early diagnosis, genetic counselling and careful management and follow-up of JBS patients, which may avoid severe clinical consequences and lower the mortality risk. It may provide further insights and a better characterization of JBS, suggesting new elements of the genotype-phenotype correlations.

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