The performance and microbial diversity of temperature-phased hyperthermophilic and thermophilic anaerobic digestion system fed with organic waste

2008 ◽  
Vol 57 (2) ◽  
pp. 283-289 ◽  
Author(s):  
M. Y. Lee ◽  
J. H. Cheon ◽  
T. Hidaka ◽  
H. Tsuno
Keyword(s):  
Anaerobic Digestion ◽  
Microbial Diversity ◽  
Conversion Efficiency ◽  
Methane Conversion ◽  
Organic Waste ◽  
Effect Of Temperature ◽  
High Concentration ◽  
Thermophilic Anaerobic Digestion ◽  
In Series ◽  
Increasing Temperature

The objective of this study was to evaluate the performances and microbial diversities for development of the effective hyperthermophilic digester system that consists of a hyperthermophilic reactor and hyperthermophilic or thermophilic reactor in series. Lab-scale reactors were operated continuously fed with artificial kitchen garbage. The effect of temperature on the acidification step was firstly investigated. Results indicated that 20.8% of COD solubilization was achieved at 70°C, with 12.6% at 80°C. The average protein solubilization reached 31% at 80°C. Methane conversion efficiency following the acidification was around 85% on average at 55°C, but decreased with increasing temperature and methane gas was not produced over 73°C. As well, bacteria affiliated with the methanogens dominated the population below 65°C, while those affiliated with acidogens were predominant over 73°C. These results indicated that the hyperthermophilic process has considerable benefits to treat wastewater or waste containing high concentration of protein.

scholarly journals Effects of Crush Process on Methane Conversion Efficiency in Thermophilic Anaerobic Digestion with Coffee Grounds

2014 ◽  
Vol 12 (3) ◽  
pp. 245-257
Author(s):  
Yugo TAKABE ◽  
Kohei YAMASE ◽  
Kohsuke WATANABE ◽  
Yasunari KUSUDA ◽  
Tadao MIZUNO ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Conversion Efficiency ◽  
Methane Conversion ◽  
Thermophilic Anaerobic Digestion ◽  
Coffee Grounds

Biopolymers modulate microbial communities in municipal organic waste digestion

2020 ◽  
Vol 96 (10) ◽  
Author(s):  
Francesca Bandini ◽  
Chiara Misci ◽  
Eren Taskin ◽  
Pier Sandro Cocconcelli ◽  
Edoardo Puglisi
Keyword(s):  
Organic Matter ◽  
Anaerobic Digestion ◽  
Microbial Communities ◽  
Organic Waste ◽  
High Throughput Sequencing ◽  
Fungal Communities ◽  
Organic Fraction ◽  
Thermophilic Anaerobic Digestion ◽  
A Minor ◽  
Real Plant

ABSTRACT The development of biopolymers has raised issues about their recalcitrance in the environment. Their disposal is mainly carried out with the organic fraction of municipal solid waste (OFMSW) through thermophilic anaerobic digestion and aerobic composting, bioprocesses aimed at turning organic matter into biogas and compost. However, the effects of biopolymers on OFMSW treatment, on the final compost and on the microbial communities involved are partly unexplored. In this study, the OFMSW treatment was reproduced on a laboratory-scale respecting real plant conditions and testing the impacts of mixing polylactic acid (PLA) and starch-based bioplastic (SBB) separately. The dynamics of bacterial, archaeal and fungal communities during the process was screened by high-throughput sequencing (HTS) of phylogenetic amplicons. Starch-based bioplastic showed a minor and heterogeneous microbial diversity between the anaerobic and aerobic phases. Contrariwise, PLA treatment resulted in wider and more diverse bacterial and fungal communities for the compost and the aerobic biofilm. Since the biodiversity in compost may play a crucial role in its stability and safety, the modulation of environmental microbial communities induced by higher concentrations of PLA in OFMSW treatment can pose relevant issues.

Degradation characteristics of polylactide in thermophilic anaerobic digestion with hyperthermophilic solubilization condition

2011 ◽  
Vol 64 (11) ◽  
pp. 2135-2142 ◽  
Author(s):  
F. Wang ◽  
T. Hidaka ◽  
T. Oishi ◽  
S. Osumi ◽  
J. Tsubota ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Methane Conversion ◽  
Experimental Results ◽  
Phase System ◽  
Two Phase ◽  
Thermophilic Anaerobic Digestion ◽  
Promotional Effect ◽  
Thermophilic Condition ◽  
Ammonia Addition ◽  
Control Batch

To test whether hyperthermophilic treatment promotes polylactide (PLA) dissolution and methane conversion under anaerobic digestion conditions, a single thermophilic control reactor (55 °C) and a two-phase system consisting of a hyperthermophilic reactor (80 °C) and a thermophilic reactor (55 °C) were continuously fed with a mixture of PLA and artificial kitchen garbage. In Runs 1 and 2, the PLA dissolution ratios in the two-phase system were 79.2 ± 6.5% and 85.2 ± 7.0%, respectively, higher than those of the control. Batch experimental results indicated that hyperthermophilic treatment could promote PLA dissolution to a greater degree as compared with single thermophilic treatment and that ammonia addition also had a promotional effect on PLA dissolution. In the two-phase system, after hyperthermophilic treatment, dissolved PLA was converted to methane gas under the subsequent thermophilic condition.

Design and Testing of a Mini-Plant for Conversion of Organic Waste to Biogas

2011 ◽  
Vol 367 ◽  
pp. 537-544
Author(s):  
Patrick Ebunilo ◽  
David Otiede
Keyword(s):  
Anaerobic Digestion ◽  
Ambient Temperature ◽  
Conversion Efficiency ◽  
Organic Waste ◽  
Temperature Range ◽  
Design And Testing ◽  
Good Percentage ◽  
Blue Flame

An experimental organic waste to biogas conversion mini-plant that works by anaerobic digestion has been designed, fabricated and tested. The demonstration involved the use of primarily, a biodigester and few other components. The organic waste was made into slurry and digested anaerobically for 14 days at an ambient temperature range of 28 to 32°C. The flame of biogas generated burnt with smokeless blue flame, indicating the presence of a colourless odourless gas called methane. The biodigester achieved a conversion efficiency of 64 percent. This equipment can be used to meet a good percentage of the fuel needs in Nigeria.

scholarly journals Methane conversion efficiency as a simple control parameter for an anaerobic digester at high loading rates

2011 ◽  
Vol 64 (2) ◽  
pp. 534-540 ◽  
Author(s):  
W. Charles ◽  
N. P. Carnaje ◽  
R. Cord-Ruwisch
Keyword(s):  
Anaerobic Digestion ◽  
Production Rate ◽  
Conversion Efficiency ◽  
Methane Conversion ◽  
Control Parameter ◽  
Loading Rate ◽  
High Loading ◽  
Loading Rates ◽  
Ch4 Production ◽  
On Line

The anaerobic digestion process is globally applied to the treatment of highly concentrated wastes such as industrial and rural effluents, and sewage sludge. However, it is known to be relatively unstable. When loaded with high concentrations of organic material, unwanted volatile fatty acids (VFA) are often produced rather than methane (CH4) gas which can lead to digester acidification and failure. This study investigated digester behaviour under high loading rates, testing the usefulness of stoichiometric methane conversion efficiency as a digester control parameter at high loading rates. Our results show that, in general, the CH4 production rate was proportional to the feed rate (loading rate). However, at very high loading rates, the CH4 production rate was not proportional to the increase in the feeding rate. Consequently, VFA accumulated and the H2 partial pressure increased. The proportionality of the loading rate and gas production rate is stoichiometrically expressed as the conversion efficiency. We found that conversion efficiency was a useful indicator as an early warning of digester imbalance. The digester remained stable at conversion efficiencies above 75%. Dropping below 70% signified the onset of digester failure. As loading rate and methane production data are readily available on-line in most anaerobic digestion plants, the conversion efficiency can be monitored on-line and used as an efficient control technique to maintain safe operation of anaerobic digesters at high loading rates.

Temperature Characteristics of the Methanogenesis Process in Anaerobic Digestion

1987 ◽  
Vol 19 (1-2) ◽  
pp. 299-300 ◽  
Author(s):  
C. Y. Lin ◽  
T. Noike ◽  
K. Sato ◽  
J. Matsumoto
Keyword(s):  
Anaerobic Digestion ◽  
Growth Yield ◽  
Utilization Rate ◽  
Specific Substrate ◽  
High Concentration ◽  
Temperature Characteristics ◽  
Substrate Removal ◽  
Rate Dependent ◽  
Specific Substrate Utilization Rate ◽  
Increasing Temperature

Experiments using high concentration of the major intermediates of anaerobic digestion were conducted with anaerobic chemostat-type reactors to investigate the temperature characteristics of the methanogenesis process. Temperature ranging from 15°C to 50°C were studied. The optimum temperature was 35°C. The methane production was temperature and loading rate dependent. Bacilli were the predominant microbial species and this predominance was independent of digestion temperature. At the mesophilic range, with increasing temperature the saturation constant (Ks) decreased, while the maximum specific substrate utilization rate (vmax) and growth yield (Yg) increased. Their temperature characteristics were described using exponential expressions. For retention times longer than 8 days, the process progressed normally and satisfactorily even at 25°C, and the substrate removal efficiency was more than 96% which was the same as that at 35°C. At the temperature range of 25°C to 35°C, the simulation model is

Highly-efficient Anaerobic Digestion of Refractory Organic Waste Using Subcritical Water Hydrolysis as Pretreatment Process

2012 ◽  
Vol 48 (1) ◽  
pp. 23-27
Author(s):  
TOMONAO MIYASHIRO ◽  
QINGHONG WANG ◽  
YINGNAN YANG ◽  
KAZUYA SHIMIZU ◽  
NORIO SUGIURA ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Organic Waste ◽  
Subcritical Water ◽  
Highly Efficient ◽  
Water Hydrolysis ◽  
Subcritical Water Hydrolysis
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