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.

Performance of Hero's Turbine Using Two-phase Mixture as Working Fluid : Experimental Results in an Air-water Two-phase System

1984 ◽  
Vol 27 (234) ◽  
pp. 2795-2802 ◽  
Author(s):  
Koji AKAGAWA ◽  
Terushige FUJII ◽  
Sigeo TAKAGI ◽  
Masaru TAKEDA ◽  
Kouich TSUJI
Keyword(s):  
Experimental Results ◽  
Working Fluid ◽  
Phase System ◽  
Two Phase ◽  
Phase Mixture

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.

Performance and energy aspects of single and two phase thermophilic anaerobic digestion of waste activated sludge

2016 ◽  
Vol 86 ◽  
pp. 1324-1331 ◽  
Author(s):  
Wanderli Rogério Moreira Leite ◽  
Marco Gottardo ◽  
Paolo Pavan ◽  
Paulo Belli Filho ◽  
David Bolzonella
Keyword(s):  
Anaerobic Digestion ◽  
Activated Sludge ◽  
Waste Activated Sludge ◽  
Two Phase ◽  
Thermophilic Anaerobic Digestion ◽  
Energy Aspects

Comparison of One-Phase and Two-Phase Anaerobic Digestion Processes in Characteristics of Substrate Degradation and Bacterial Population Levels

1991 ◽  
Vol 23 (7-9) ◽  
pp. 1157-1166 ◽  
Author(s):  
Tian Cheng Zhang ◽  
Tatsuya Noike
Keyword(s):  
Anaerobic Digestion ◽  
Bacterial Population ◽  
Removal Rate ◽  
Cod Removal ◽  
Phase System ◽  
Two Phase ◽  
Experimental Conditions ◽  
Substrate Degradation ◽  
Cod Removal Rate ◽  
The One

The comparison of one-phase and two-phase anaerobic digestion processes in the characteristics of substrate degradation and the bacterial population levels was investigated by using the chemostat-type reactors to which starch was fed as substrate when both processes were operated under the same experimental conditions. By decreasing the SRTs of both systems from 10.2 d to 5 d, 2.5 d and 1.75 d. it was found that the two-phase system was more stable to the change in pH than one-phase system. The CH4 recovery rates and COD removal rates in the two-phase system increased by 4 to 9% and 3 to 10%. respectively, although the CH4 recovery rate and the COD removal rate in the one-phase system were slightly higher than those in the two-phase system at the SRT of 10.2 d. The concentration of propionate in the effluent of the one-phase system was 30 to 50% higher than that in the two-phase system; while the concentrations of acetate and butyrate in the one-phase system were slightly lower than those in the two-phase one. The enumeration of the bacteria was performed by the MPN method. The population levels of acidogenic bacteria in both systems were in the same order (108 to 1010 MPN/ml). the population levels of hydrogenotrophs were also in the same order as the acidogenic bacteria in the two-phase system, while the population levels of hydrogenotrophs were 10 to 100 fold less than that of acidogenic bacteria in the one-phase system. The number of HAc-utilizing methanogens in the methanogenesis of the two-phase system were 2 to 10 times higher than that in the one-phase system. Therefore, the one-phase system cannot be regarded simply as the sum of acidogenesis and methanogenesis.

A hybrid two-phase system for anaerobic digestion of food waste

2002 ◽  
Vol 45 (12) ◽  
pp. 159-165 ◽  
Author(s):  
J.Y. Wang ◽  
H.L. Xu ◽  
J.H. Tay
Keyword(s):  
Anaerobic Digestion ◽  
Food Waste ◽  
Batch Reactor ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Phase System ◽  
Bioreactor Landfills ◽  
Two Phase ◽  
Methanogenic Phase

A hybrid two-phase system, consisting of a solid waste reactor as the acidification reactor and a wastewater reactor, i.e. an upflow anaerobic sludge blanket (UASB) reactor, as the methanogenic reactor, for anaerobic digestion of food waste was investigated. After the pre-acidification stage, COD and total VFA removals in the methanogenic phase were in the ranges of 74-93% and 77-100%, respectively, while leachate COD and total VFA concentrations in the acidification phase decreased by 95% and 97-99%, respectively. Some 99% of the total CH4 generated was from the methanogenic phase with the CH4 content of 68-70%. About 77-79% of TOC, 57-60% of volatile solids and 79-80% of total COD were removed. The results of this laboratory-scale study show that the hybrid two-phase anaerobic batch reactor system is suitable for effective conversion of food waste into CH4 and CO2. The hybrid two-phase system can be further developed into an effective and efficient way to enhance waste stabilization in operating bioreactor landfills.

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