A Potential Treatment Alternative for Swine Wastewater in the Tropics

1985 ◽  
Vol 17 (4-5) ◽  
pp. 819-831 ◽  
Author(s):  
P. Y. Yang ◽  
S. Y. Nagano
Keyword(s):  
Anaerobic Digestion ◽  
Production Rate ◽  
Algal Biomass ◽  
Energy Production ◽  
Loading Rate ◽  
Gas Production ◽  
Energy Utilization ◽  
Swine Wastewater ◽  
N Removal ◽  
The Tropics

Development of a low-cost and effective swine waste management system in the tropics is the main objective of this study. Because of the apppropriate temperature environment and abundance of sunlight, an integration of an anaerobic digestion and an algal biomass process was selected and investigated. A pilot, plant integrating a 20 m3 anaerobic digester with sludge recycling and a 120 m3 algal-biomass raceway were installed and evaluated. Maximum gas production rate of 1.527 liter/liter/day (69% methane content) can be achieved by a TVS loading rate of 4.23 gram/liter/day. A sludge production rate of 0.82-2.62 g TS/liter is obtained from a TVS loading rate of 0.76-4.23 g TVS/liter/day. Critical SRT for maximum gas production rate is 2.67. For the algal biomass raceway, a loading rate of 0.097 g SCOD/liter/day or 0.017 g NH4-N/liter/day would achieve SCOD and NH4-N removal efficiencies of 94.44% and 98.42%, respectively. Combining the previous analysis of energy input and land requirement for an algal biomass raceway and mass balance of energy production and utilization, integrating the energy production (anaerobic digestion) and energy utilization (dehydration of digested sludge and power requirement of raceway) provides a great potential for a swine wastewater treatment in the tropics.

Study of Methane Production by High Temperature Anaerobic Fermentation of Chicken Manure and Stalks

2020 ◽  
Vol 14 (4) ◽  
pp. 551-557
Author(s):  
Yongku Li ◽  
Xiaomin Hu ◽  
Lei Feng
Keyword(s):  
High Temperature ◽  
Anaerobic Digestion ◽  
Production Rate ◽  
Methane Production ◽  
Anaerobic Fermentation ◽  
Biogas Production ◽  
Gas Production ◽  
Chicken Manure ◽  
Biogas Slurry ◽  
Production Rates

The changing parameters, as the biogas production rate, the methane production rate, the cumulative biogas amount, the cumulative methane amount, the biogas composition, pH etc. in high temperature anaerobic fermentation of chicken manure and stalks were analyzed by experiments with different mass ratios of chicken manure or livestock manure and stalks with a high C/N ratio. The methane production mechanism of high temperature anaerobic digestion of chicken manure and stalks was discussed in detail. It showed that not only the biogas production rates but also the methane production rates of R1–R7 demonstrated the trend of initial increase and then decrease after 50 d of high temperature anaerobic digestion. Besides, the gas production of R1 with pure chicken manure stopped on the 30th d of the reaction. The gas production of other groups R2–R7 also stopped on the corresponding 34th, 36th, 36th, 37th, 37th, and 37th day, respectively. At the end of the reaction, the cumulative biogas amounts and the cumulative methane amounts of R1–R7 were 411.58 and 269.54, 459.91 and 314.41, 425.32 and 294.11, 401.85 and 272.54, 382.63 and 257.07, 363.04 and 218.16, and 257.15 and 160.10 N ml/(g VS). The biogas slurry pH of R1–R7 all demonstrated a trend of initial decrease and then increase, e. g., pH of R2 reached the minimum of 5.94 on the 5th day. pH values of other groups were between 6.01 and 6.39. After the addition of 4 g of sodium bicarbonate on the 7th day, biogas slurry pH of R1–R7 all increased. pH was maintained between 7.16 and 7.44 until the end of the reaction.

Design of the Solar Energy-Heated Biogas Digester

2014 ◽  
Vol 953-954 ◽  
pp. 103-106
Author(s):  
Jin Yang Li ◽  
Jian Li ◽  
Qing Yu Liu ◽  
Hao Zheng
Keyword(s):  
Anaerobic Digestion ◽  
Solar Energy ◽  
Production Rate ◽  
Northern China ◽  
Gas Production ◽  
Raw Material ◽  
Solar Thermal ◽  
Biogas Slurry ◽  
Optimum Temperature ◽  
Working Principle

Heating biogas digester is essential in northern China, especially during the winter. Solar energy-heated biogas digester is a facility that radiates heat by the solar thermal, which maintains the temperature of the biogas digester. The working principle behind this facility is the division of the traditional biogas digester into three parts, namely, raw material storage section, biogas slurry storage section, and anaerobic digestion section. We only heat the anaerobic digestion section to decrease the heating volume and reduce the heat dissipating surface, thereby saving energy. Solar energy is unstable, and the anaerobic digestion section needs to be maintained at its best temperature, thus, we control the raw material inlet at its optimum temperature. This biogas digester improves the anaerobic digestion condition and enhances gas production rate, which enables the efficient function of the digester during winter.

Production of Biogas by Anaerobic Digestion of Food Waste and Process Simulation

2014 ◽  
Author(s):  
Md. Abdullah Hil Baky ◽  
Muhammad Nazmul Hassan Khan ◽  
Md. Faisal Kader ◽  
Habibullah Amin Chowdhury
Keyword(s):  
Organic Matter ◽  
Anaerobic Digestion ◽  
Food Waste ◽  
Process Simulation ◽  
Loading Rate ◽  
Gas Production ◽  
Biogas Plant ◽  
Experimental Results ◽  
Sustainable Solutions ◽  
University Of Technology

Anaerobic Digestion is a biological process that takes place naturally when microorganisms break down organic matter in the absence of oxygen. In an enclosed chamber, controlled anaerobic digestion of organic matter produces biogas which is predominantly methane. The produced methane then can be directly used for rural cooking; or after certain conditioning, can be used in onsite power generation, heating homes or as vehicular fuel. Besides, food waste is increasingly becoming a major problem in every society imposing serious economic and environmental concerns. For this reason, many contemporary researches are emphasizing in finding sustainable solutions to recycle and produce energy from such waste. In this context, this paper aims to study and optimize the production of biogas from food waste (rice). For the experiment, an existing wet digestion biogas plant installed in Islamic University of Technology was used. The food waste (rice) for the research was collected from the cafeteria of Islamic University of Technology. Furthermore, a process simulation was performed by PROII software to estimate the methane production rate. Eventually, the simulated and experimental results were compared. The duration of the study period was 120 days. The experimental results showed that an average specific gas production of 14.4 kg-mol/hr can be obtained for 0.05 kg-mol/hr of starch loading rate. In case of the simulated results, the gas production was found to be 19.82 kg-mol/hr for the same loading rate of starch. The percentage of methane and CO2 obtained in the biogas plant was 69% and 29% respectively.

Modelling of anaerobic digestion using self-organizing maps and artificial neural networks

2000 ◽  
Vol 41 (12) ◽  
pp. 149-156 ◽  
Author(s):  
P. Holubar ◽  
L. Zani ◽  
M. Hagar ◽  
W. Fröschl ◽  
Z. Radak ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Production Rate ◽  
Regression Coefficient ◽  
Gas Production ◽  
Neural Nets ◽  
Organic Loading Rate ◽  
Self Organizing Map ◽  
Gas Composition ◽  
Volatile Fatty Acid Concentration ◽  
Self Organizing

In this work the training of a self-organizing map and a feed-forward back-propagation neural network was made. The aim was to model the anaerobic digestion process. To produce data for the training of the neural nets an anaerobic digester was operated at steady state and disturbed by pulsing the organic loading rate. Measured parameters were: gas composition, gas production rate, volatile fatty acid concentration, pH, redox potential, volatile suspended solids and chemical oxygen demand of feed and effluent. It could be shown that both types of self-learning networks in principle could be used to model the process of anaerobic digestion. Using the unsupervised Kohonen self-organizing map, the model's predictions could not follow the measurements in all details. This resulted in an unsatisfactory regression coefficient of R2= 0.69 for the gas composition and R2= 0.76 for the gas production rate. When the supervised FFBP neural net was used the training resulted in more precise predictions. The regression coefficient was found to be R2= 0.74 for the gas composition and R2== 0.92 for the gas production rate.

Prediction of Landfill Gas Production of Municipal Solid Waste and Energy Utilization Analysis

2013 ◽  
Vol 860-863 ◽  
pp. 3119-3122
Author(s):  
Dan Li ◽  
Zhi Xin Pan ◽  
Yong'an Ao
Keyword(s):  
Municipal Solid Waste ◽  
Solid Waste ◽  
Production Rate ◽  
Landfill Gas ◽  
Gas Production ◽  
Energy Utilization ◽  
Environmental Benefit ◽  
Landfill Sites ◽  
Production Quantity

It is an important factor to predict the LFG production rate and production quantity accurately and conveniently for the LFG recovery projects.According to the characters of Chinese Municipal Solid Waste (MSW) component, the paper studies on the Landfill Gas (LFG) models, and establishes the LFG model that is adapt to the characters of Chinese MSW component. The paper takes the Laohuchong landfill sites in Shenyang for example, predicts the LFG production and analyses the energy utilization and environmental benefit.

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.

scholarly journals Treatment of winery wastewater by an anaerobic sequencing batch reactor

2002 ◽  
Vol 45 (10) ◽  
pp. 219-224 ◽  
Author(s):  
C. Ruíz ◽  
M. Torrijos ◽  
P. Sousbie ◽  
J. Lebrato Martínez ◽  
R. Moletta ◽  
...  
Keyword(s):  
Production Rate ◽  
Sequencing Batch Reactor ◽  
Loading Rate ◽  
Batch Reactor ◽  
Gas Production ◽  
Operating Conditions ◽  
Organic Loading Rate ◽  
Organic Loading ◽  
Winery Wastewater ◽  
Anaerobic Sequencing Batch Reactor

Treatment of winery wastewater was investigated using an anaerobic sequencing batch reactor (ASBR). Biogas production rate was monitored and permitted the automation of the bioreactor by a simple control system. The reactor was operated at an organic loading rate (ORL) around 8.6 gCOD/L.d with soluble chemical oxygen demand (COD) removal efficiency greater than 98%, hydraulic retention time (HRT) of 2.2 d and a specific organic loading rate (SOLR) of 0.96 gCOD/gVSS.d. The kinetics of COD and VFA removal were investigated for winery wastewater and for simple compounds such as ethanol, which is a major component of winery effluent, and acetate, which is the main volatile fatty acid (VFA) produced. The comparison of the profiles obtained with the 3 substrates shows that, overall, the acidification of the organic matter and the methanisation of the VFA follow zero order reactions, in the operating conditions of our study. The effect on the gas production rate resulted in two level periods separated by a sharp break when the acidification stage was finished and only the breaking down of the VFA continued.

scholarly journals Opportunities for Green Energy through Emerging Crops: Biogas Valorization of Cannabis sativa L. Residues

Climate ◽  
2019 ◽  
Vol 7 (12) ◽  
pp. 142 ◽  
Author(s):  
Carla Asquer ◽  
Emanuela Melis ◽  
Efisio Antonio Scano ◽  
Gianluca Carboni
Keyword(s):  
Anaerobic Digestion ◽  
Loading Rate ◽  
Cannabis Sativa ◽  
Biogas Production ◽  
Gas Production ◽  
Enzymatic Treatment ◽  
Laboratory Scale ◽  
Industrial Plant ◽  
Organic Loading Rate ◽  
Organic Loading

The present work shows the experimental evidence carried out on a pilot scale and demonstrating the potential of Cannabis sativa L. by-products for biogas production through anaerobic digestion. While the current state-of-the-art tests on anaerobic digestion feasibility are carried out at the laboratory scale, the here described tests were carried out at a pilot-to-large scale. An experimental campaign was carried out on hemp straw residues to assess the effective performance of this feedstock in biogas production by reproducing the real operating conditions of an industrial plant. An organic loading rate was applied according to two different amounts of hemp straw residues (3% wt/wt and 5% wt/wt). Also, specific bioenhancers were used to maximize biogas production. When an enzymatic treatment was not applied, a higher amount of hemp straw residues determined an increase of the median values of the gas production rate of biogas of 92.1%. This reached 116.6% when bioenhancers were applied. The increase of the specific gas production of biogas due to an increment of the organic loading rate (5% wt/wt) was +77.9% without enzymatic treatment and it was +129.8% when enzymes were used. The best management of the biodigester was found in the combination of higher values of hemp straw residues coupled with the enzymatic treatment, reaching 0.248 Nm3·kgvolatile solids−1 of specific biogas production. Comparisons were made between the biogas performance obtained within the present study and those found in the literature review coming from studies on a laboratory scale, as well as those related to the most common energy crops. The hemp straw performance was similar to those provided by previous studies on a laboratory scale. Values reported in the literature for other lignocellulosic crops are close to those of this work. Based on the findings, biogas production can be improved by using bioenhancers. Results suggest an integration of industrial hemp straw residues as complementary biomass for cleaner production and to contribute to the fight against climate change.

scholarly journals Effect Of Co-Digestion Of Source Separated Organics And Manure On Methane Production

2021 ◽  
Author(s):  
Devarshi Sevak ◽  
Elsayed Elbeshbishy
Keyword(s):  
Anaerobic Digestion ◽  
Production Rate ◽  
Methane Production ◽  
Gas Production ◽  
Mixture Ratio ◽  
Biomethane Potential ◽  
Methane Production Rate ◽  
Biomethane Production ◽  
Mesophilic Condition

Anaerobic co-digestion (AcoD) is more advantageous than conventional mono-digestion, because of higher gas production rate. This study was aimed to study the effect of mixture ratio in codigestion of manure and source separated organics (SSO) in mesophilic condition. Manure and SSO at different mixture ratios of 9:1, 7:3, 5:5, 3:7, and 1:9 on a volumetric basis were used to determine the effect of the mixture ratios on methane production in biomethane potential assay (BMP). Results showed that co-digestion of SSO and manure at the ratio of 1:9 (V/V) resulted in the highest biomethane production rate of 46 mL CH4 /day. In comparison, the maximum methane production rate for anaerobic digestion of manure alone was 43 mL CH4 /day. When manure is mixed with SSO at a ratio of 5:5, about 15% higher cumulative methane production has been achieved. This research also verified the advantages of co-digestion over mono-digestion. Keywords: Anaerobic Digestion, Co-digestion, Source Separated Organics (SSO), Manure

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