Amending anaerobic bioreactors with pyrogenic carbonaceous materials: the influence of material properties on methane generation

2018 ◽  
Vol 4 (11) ◽  
pp. 1794-1806 ◽  
Author(s):  
Qiwen Cheng ◽  
Francis L. de los Reyes ◽  
Douglas F. Call
Keyword(s):  
Electrical Conductivity ◽  
Material Properties ◽  
Methane Production ◽  
Carbonaceous Material ◽  
Batch Reactors ◽  
Short Term ◽  
Methane Generation ◽  
Anaerobic Bioreactors ◽  
Multiple Material ◽  
The Impact

The impact of pyrogenic carbonaceous material amendments on methane production in short-term anaerobic batch reactors depended on multiple material properties, including, but not limited to, electrical conductivity.

Comparison of methane production by co-digesting fruit and vegetable waste with first stage and second stage anaerobic digester sludge from a two stage digester

2012 ◽  
Vol 65 (7) ◽  
pp. 1252-1257 ◽  
Author(s):  
Nathan D. Park ◽  
Ronald W. Thring ◽  
Steve S. Helle
Keyword(s):  
Methane Production ◽  
Anaerobic Digester ◽  
Batch Reactors ◽  
Vegetable Waste ◽  
Fruit And Vegetable ◽  
Methane Generation ◽  
Second Stage ◽  
Substrate Ratio ◽  
Sewer Sludge ◽  
Anaerobic Digester Sludge

Fruit and vegetable waste (FVW) was co-digested with first stage (FSS) and second stage anaerobic digester sludge (SSS) separately, over the course of 10 days, in batch reactors. Addition of FVW significantly increased the methane production in both sludges. After 10 days of digestion FSS + FVW produced 514 ± 57 L CH4 kg VS−1added compared with 392 ± 16 L CH4 for the SSS + FVW. The increased methane yield was most likely due to the higher inoculum substrate ratio of the FSS. The final VS and COD contents of the sewer sludge and FVW mixtures were not significantly different from the control values suggesting that all of the FVW added was degraded within 10 days. It is recommended that FVW be added to the first stage of the anaerobic digester in order to maximize methane generation.

scholarly journals Estimation of future methane production from Hellenic landfills

2013 ◽  
Vol 11 (2) ◽  
pp. 162-171
Keyword(s):  
Methane Production ◽  
Energy Production ◽  
Phase Model ◽  
Methane Generation ◽  
Sanitary Landfills ◽  
Multi Phase ◽  
The Impact ◽  
The Eu

The main objective of this research was to predict expected methane generation in Hellenic sanitary landfills, in order to evaluate its potential for energy production and to ensure health and safety in and around these sites on the long term. The study was performed for the period 2008 – 2028 with the use of a multi-phase model and included also a sensitivity analysis in order to determine the impact of certain waste parameters. In this context, two ‘extreme’ reference scenarios were formulated and assessed, one anticipating fulfilment of the EU landfill directive (which sets limits to the amount of biodegradable and packaging materials to be deposited in sanitary landfills) whereas a second (do-nothing scenario) assuming no such timely compliance.

scholarly journals The Effect of Perfluorooctane Sulfonate, Exposure Time, and Chemical Mixtures on Methanogenic Community Structure and Function

2015 ◽  
Vol 8s2 ◽  
pp. MBI.S31345 ◽  
Author(s):  
Patrick J. McNamara ◽  
Timothy M. LaPara ◽  
Paige J. Novak
Keyword(s):  
Community Structure ◽  
Exposure Time ◽  
Methane Production ◽  
Perfluorooctane Sulfonate ◽  
Structure And Function ◽  
Short Term ◽  
Anaerobic Digesters ◽  
And Function ◽  
The Impact

A plethora of organic micropollutant mixtures are found in untreated municipal wastewater. Anaerobic digesters receive large loadings of hydrophobic micropollutants that sorb to wastewater biosolids. Despite micropollutants being pervasive as mixtures, little research is available to explain the impact that mixtures of compounds, as well as exposure time, have on microbial communities in anaerobic digesters. Perfluorooctane sulfonate (PFOS) was added to anaerobic enrichment cultures in both short-term (14 days) and long-term (140 days) studies to determine the impact of exposure time. Additionally, triclosan was added during the experiments to investigate the impact of mixtures on community structure and function. PFOS did not alter methane production in short-term studies, but in long-term studies, methane production increased, consistent with our hypothesis that PFOS may act as a metabolic uncoupler. The impact of triclosan on methane production was exacerbated when PFOS was already present in the anaerobic enrichment cultures. Triclosan also had greater impacts on microbial community structures in the bottles that had been exposed to PFOS long-term. These results demonstrate that both chemical mixtures and exposure time are important parameters to address when trying to define the impacts of micropollutants on anaerobic microbial communities.

Anaerobic co-digestion of winery wastewater

2007 ◽  
Vol 56 (2) ◽  
pp. 49-54 ◽  
Author(s):  
L. Rodríguez ◽  
J. Villaseñor ◽  
F.J. Fernández ◽  
I.M. Buendía
Keyword(s):  
Anaerobic Digestion ◽  
Methane Production ◽  
Reduction Rate ◽  
Operational Performance ◽  
Waste Activated Sludge ◽  
Batch Reactors ◽  
Methane Generation ◽  
Winery Wastewater ◽  
Methane Production Rate ◽  
Mesophilic Conditions

The operational performance of anaerobic batch reactors treating winery wastewater (WW) combined with waste activated sludge (WAS) in different proportions was investigated under mesophilic conditions. In these experiments it was shown that for anaerobic digestion of WW alone, methane production rate was lower than the rates achieved when WW and WAS were treated together. When WW was mixed with WAS at a concentration of 50% WW resulted in the highest methane production rates. A simplified anaerobic model was used to determine the main kinetic parameters; maximum COD reduction rate (qDA) and maximum methane generation rate (kmax). The maximum values of qDA and kmax were 16.50 kgCOD COD−1 d−1 and 14.34 kgCOD kgCOD−1 d−1, respectively.

A Newspaper’s Effect on the Strength of Automatic Associations in Memory

2012 ◽  
Vol 24 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Florian Arendt
Keyword(s):  
Treatment Group ◽  
Term Effect ◽  
Control Group ◽  
Implicit Measure ◽  
Short Term ◽  
Short Term Treatment ◽  
Short Term Effect ◽  
Automatic Associations ◽  
Foreign Nationality ◽  
The Impact

A test was done to see if reading a newspaper which consistently overrepresents foreigners as criminals strengthens the automatic association between foreign country and criminal in memory (i.e., implicit cultivation). Further, an investigation was done to find out if reading articles from the same newspaper produces a short-term effect on the same measure and if (1) emotionalization of the newspaper texts, (2) emotional reactions of the reader (indicated by arousal), and (3) attributed text credibility moderate the short-term treatment effect. Eighty-five participants were assigned to one of three experimental conditions. Participants in the control group received short factual crime texts, where the nationality of the offender was not mentioned. Participants in the factual treatment group received the same texts, but the foreign nationality was mentioned. Participants in the emotionalized treatment group received emotionalized articles (i.e., texts which are high in vividness and frequency) covering the same crimes, with the foreign nationality mentioned. Supporting empirical evidence for implicit cultivation and a short-term effect was found. However, only emotionalized articles produced a short-term effect on the strength of the automatic association, indicating that newspaper texts must have a minimum of stimulus intensity to overcome an effect threshold. There were no moderating effects of arousal or credibility pertaining to the impact on the implicit measure. However, credibility moderated the short-term effect on a first-order judgment (i.e., estimated frequency of foreigners of all criminals). This indicates that a newspaper’s effect on the strength of automatic associations is relatively independent from processes of propositional reasoning.

Diatoms in the Amur Bay sediments (Sea of Japan) and the impact of typhoons on their accumulation over the last 2000 years

2019 ◽  
pp. 252-256
Author(s):  
Irina A. Prushkovskaya ◽  
Ira B. Tsoy
Keyword(s):  
Sea Of Japan ◽  
Short Term ◽  
Catastrophic Events ◽  
Bromine Content ◽  
Amur Bay ◽  
The Impact

The study of diatoms in the sediments of the Amur Bay (Sea of Japan), formed over the last 2000 years, showed that the sharp short-term drops in the concentration of diatoms coincide with the minima of bromine content, which can be explained by the influence of typhoons or other catastrophic events leading to floods and used later in paleoreconstructions.

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