scholarly journals Influence of Inoculum and Substrate Concentration on Anaerobic Digestion of Ocimum Sanctum (Holy Basil)

2020 ◽  
pp. 217-219
Keyword(s):  
Anaerobic Digestion ◽  
Substrate Concentration ◽  
Oxygen Demand ◽  
Ocimum Sanctum ◽  
Batch Reactors ◽  
Anaerobic Microorganisms ◽  
Volatile Solids ◽  
Degradation Rates ◽  
Holy Basil ◽  
Anaerobic System

“Anaerobic digestion is the constrained degradation of usual organic waste in the oxygen deficient environment and the existence of anaerobic microorganisms. Anaerobic digestion is accomplished by microbial diversity. “Substrate loading rate is a measure of biological conversion capacity of anaerobic system and has significant influence on the process performance. Henceforth in the current work, the outcome of different concentrations of substrate to inoculum (0.3, 0.6 and 0.9) on anaerobic digestion of Holy Basil (Ocimum sanctum) used as substrate was explored in batch reactors for 45 days along with heterogenous cowdung as Inoculum. Temperature and biogas were noted daily. “The Volatile Solids (VS), Chemical Oxygen Demand (COD), Total Kjeldhal Nitrogen (TKN) and Phosphorous were analyzed at an interval of 5 days. Though the degradation rates of various parameters showed a higher efficiency at 0.3 inoculum to “substrate concentration, the biogas generation was impending to be maximum at 0.6 among the various digesters.

scholarly journals Biogas from slaughter house waste and optimization of the process

2016 ◽  
Vol 51 (3) ◽  
pp. 203-214 ◽  
Author(s):  
MA Rouf ◽  
MS Islam ◽  
T Rabeya ◽  
AK Mondal ◽  
M Khanam ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Stomach Content ◽  
Oxygen Demand ◽  
Gas Production ◽  
Batch Reactors ◽  
Volatile Solid ◽  
Optimum Conditions ◽  
Slaughter House ◽  
Destruction Efficiency ◽  
Volatile Solids

To assess the potential of biogas generation by anaerobic digestion from slaughter house waste (undigested stomach content) and to determine the optimum conditions for biogas generation from the substrate, different proportions of substrate were used in six batch reactors R1, R2, R3, R4, R5 and R6. The reactors were operated with initial volatile solid concentrations of 34.00, 50.80, 67.20, 51.60, 48.10 and 63.36 g/l and corresponding specific gas production obtained was 0.258, 0.200, 0.160, 0.270, 0.201 and 0.170 l/g respectively. The volatile solids (VS) destruction efficiency was 31.71%, 29.15%, 28.26%, 32.29%, 30.56 and 29.08% as well as chemical oxygen demand (COD)  reduction achieved in the test reactors were 40.31%, 44.44%, 49.40%, 53.24%, 48.55% and 51.26% in R1, R2, R3, R4, R5 and R6 respectively. Methane yield in different reactors varied from 72% to 76%. The optimum mix for generation of biogas from the substrate was 75% slaughter waste mixed with 25% cow dung.Bangladesh J. Sci. Ind. Res. 51(3), 203-214, 2016

scholarly journals Batch and Semi-Continuous Anaerobic Digestion of Industrial Solid Citrus Waste for the Production of Bioenergy

Processes ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 648
Author(s):  
Erik Samuel Rosas-Mendoza ◽  
Andrea Alvarado-Vallejo ◽  
Norma Alejandra Vallejo-Cantú ◽  
Raúl Snell-Castro ◽  
Sergio Martínez-Hernández ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Oxygen Demand ◽  
Continuous Mode ◽  
Citrus Industry ◽  
Batch Mode ◽  
Volatile Solids ◽  
Working Volume ◽  
Plant Level ◽  
Citrus Waste ◽  
Mesophilic Conditions

The aim of this paper is to describe a study of the anaerobic digestion of industrial citrus solid waste (ISCW) in both batch and semi-continuous modes for the production of bioenergy without the elimination of D-limonene. The study was conducted at the pilot plant level in an anaerobic reactor with a working volume of 220 L under mesophilic conditions of 35 ± 2 °C. Cattle manure (CM) was used as the inoculum. Three batches were studied. The first batch had a CM/ISCW ratio of 90/10, and Batches 2 and 3 had CM/ISCW ratios of 80/20 and 70/30, respectively. In the semi-continuous mode an OLR of approximately 8 g total chemical oxygen demand (COD)/Ld (4.43 gVS/Ld) was used. The results showed that 49%, 44%, and 60% of volatile solids were removed in the batch mode, and 35% was removed in the semi-continuous mode. In the batch mode, 0.322, 0.382, and 0.316 LCH4 were obtained at STP/gVSremoved. A total of 24.4 L/d (34% methane) was measured in the semi-continuous mode. Bioenergy potentials of 3.97, 5.66, and 8.79 kWh were obtained for the respective batches, and 0.09 kWh was calculated in the semi-continuous mode. The citrus industry could produce 37 GWh per season. A ton of processed oranges has a bioenergy potential of 162 kWh, which is equivalent to 49 kWh of available electricity ($3.90).

scholarly journals Treatment of dairy waste by anaerobic co-digestion with sewage sludge

2016 ◽  
Vol 23 (1) ◽  
pp. 99-115 ◽  
Author(s):  
Agnieszka A. Pilarska ◽  
Krzysztof Pilarski ◽  
Kamil Witaszek ◽  
Hanna Waliszewska ◽  
Magdalena Zborowska ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Anaerobic Digestion ◽  
Sewage Sludge ◽  
Organic Carbon ◽  
Organic Waste ◽  
Cheese Whey ◽  
Oxygen Demand ◽  
Volatile Solids ◽  
Biomethane Production ◽  
Digested Sewage Sludge

Abstract The results of anaerobic digestion (AD) of buttermilk (BM) and cheese whey (CW) with a digested sewage sludge as inoculum is described. The substrate/inoculum mixtures were prepared using 10% buttermilk and 15% cheese whey. The essential parameters of the materials were described, including: total solids (TS), volatile solids (VS), pH, conductivity, C/N ratio (the quantitative ratio of organic carbon (C) to nitrogen (N)), alkalinity, chemical oxygen demand (COD). The potential directions of biodegradation of the organic waste types, as used in this study, are also presented. Appropriate chemical reactions illustrate the substrates and products in each phase of anaerobic decomposition of the compounds that are present in buttermilk and cheese whey: lactic acid, lactose, fat, and casein. Moreover, the biogas and biomethane production rates are compared for the substrates used in the experiment. The results have shown that buttermilk in AD generates more biogas (743 m3/Mg VS), including methane (527 m3/Mg VS), when compared with cheese whey (600 m3/Mg VS, 338 m3/Mg VS for biogas and methane, respectively).

Sludge electrooxidation as pre-treatment for anaerobic digestion

2016 ◽  
Vol 75 (4) ◽  
pp. 775-781 ◽  
Author(s):  
J. A. Barrios ◽  
U. Duran ◽  
A. Cano ◽  
M. Cisneros-Ortiz ◽  
S. Hernández
Keyword(s):  
Anaerobic Digestion ◽  
Volatile Fatty Acids ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Wastewater Sludge ◽  
Boron Doped Diamond ◽  
Boron Doped ◽  
Treatment Conditions ◽  
Volatile Solids ◽  
Pre Treatment

Anaerobic digestion of wastewater sludge is the preferred method for sludge treatment as it produces energy in the form of biogas as well as a stabilised product that may be land applied. Different pre-treatments have been proposed to solubilise organic matter and increase biogas production. Sludge electrooxidation with boron-doped diamond electrodes was used as pre-treatment for waste activated sludge (WAS) and its effect on physicochemical properties and biomethane potential (BMP) was evaluated. WAS with 2 and 3% total solids (TS) achieved 2.1 and 2.8% solubilisation, respectively, with higher solids requiring more energy. After pre-treatment, biodegradable chemical oxygen demand values were close to the maximum theoretical BMP, which makes sludge suitable for energy production. Anaerobic digestion reduced volatile solids (VS) by more than 30% in pre-treated sludge with a food to microorganism ratio of 0.15 g VSfed g−1 VSbiomass. Volatile fatty acids were lower than those for sludge without pre-treatment. Best pre-treatment conditions were 3% TS and 28.6 mA cm−2.

scholarly journals Comparison between biodegradable polymers from cassava starch and glycerol as additives to biogas production

2016 ◽  
Vol 37 (4) ◽  
pp. 1827 ◽  
Author(s):  
Paulo André Cremonez ◽  
Armin Feiden ◽  
Joel Gustavo Teleken ◽  
Samuel Nelson Melegari de Souza ◽  
Michael Feroldi ◽  
...  
Keyword(s):  
Biodegradable Polymers ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Cassava Starch ◽  
Swine Wastewater ◽  
Batch Reactors ◽  
Total Volatile ◽  
Swine Waste ◽  
Volatile Solids ◽  
Working Volume

In this study, we compared cassava starch-based biodegradable polymers (PBMs) and glycerol (G) as additives used to increase biogas production from the co-digestion of swine wastewater (ARS). We chose to work with an inoculum comprising 40% (v/v) of the total volume of the reactor; this inoculum was obtained from a Canadian model digester for treating swine waste. In the anaerobic digestion process, batch reactors were used on a laboratory scale with a total volume of approximately 4 L and a working volume of 3.2 L. Three treatments were conducted to compare the efficiency of solid removal, the chemical oxygen demand (COD), and the production of biogas. The first treatment contained only swine waste; the second included the addition of glycerol at 1, 3, and 5% (w/v); and the third treatment included the addition of 1, 3, and 5% (w/v) of PBM residue in relation to the swine wastewater. From the results, it can be concluded that higher yields were obtained for the treatment with 3% PBM and 1% glycerol. Most treatments showed high removal rates of total solids and total volatile solids. Reductions lower than 70% were obtained only for treatments with PBM and glycerol at a ratio of 5%.

Anaerobic acidification of a synthetic wastewater in batch reactors at 55°C

2002 ◽  
Vol 46 (11-12) ◽  
pp. 153-157 ◽  
Author(s):  
H.Q. Yu ◽  
H.H.P. Fang
Keyword(s):  
Fatty Acid ◽  
Substrate Concentration ◽  
Volatile Fatty Acid ◽  
Biomass Yield ◽  
Oxygen Demand ◽  
Dairy Wastewater ◽  
Synthetic Wastewater ◽  
Batch Reactors ◽  
Production Of Hydrogen ◽  
Anaerobic Acidification

Experiments were conducted to study the acidogenesis of a dairy wastewater in batch reactors at pH 5.5 and 55°C. There was a biased fermentation sequence for carbohydrate and protein, and the protein fermentation was delayed by carbohydrate. The production of hydrogen was exclusively from the fermentation of carbohydrate. Acetate and butyrate concentrations both increased rapidly at the beginning and peaked at some points, then declined in the reactors fed with 8 g-COD (chemical oxygen demand)/l, or higher concentrations. Butanol and propanol fractions increased with the substrate concentration. The metabolism shifted from the volatile fatty acid-producing pathways to the alcohol-producing pathways when the substrate concentration increased beyond 8 g-COD/l. The acidogenic biomass yield was in the range 0.19-0.25 mg-VSS/mg-COD.

Anaerobic digestion of primary sludge from chemical pre-precipitation

1997 ◽  
Vol 36 (6-7) ◽  
pp. 357-365 ◽  
Author(s):  
Wouter Ghyoot ◽  
Willy Verstraete
Keyword(s):  
Anaerobic Digestion ◽  
Wastewater Treatment Plants ◽  
Oxygen Demand ◽  
Molar Ratio ◽  
Municipal Sewage ◽  
Primary Sludge ◽  
Loading Rates ◽  
Volatile Solids ◽  
Feasible Option ◽  
Kjeldahl Nitrogen

Many existing wastewater treatment plants are to be upgraded for phosphorus removal. In our study, ferric chloride was used as a coagulant in pre-precipitation of municipal sewage. Using a Fe/P molar ratio of 0.8, removal efficiencies for suspended solids (64%), chemical oxygen demand (50%), Kjeldahl nitrogen (22%), total phosphorus (43%) and orthophosphate (51%) were obtained. Anaerobic digestion of raw primary sludge yielded a volatile solids (VS) destruction of 35% at VS loading rates of 0.60 to 0.79 kg VS/m3.d. Digestion of chemically enriched primary sludge (CEP-sludge) yielded a VS destruction of 57% at a VS loading rate of 1.36 kgVS/m3.d. Comparison of the methane production per kg VS destroyed (519 to 612 1 CH4/kgVS destroyed for primary sludge, 299 to 395 1 CH4/kgVS destroyed for CEP-sludge) evidenced a change in the composition of the organic material after precipitation with coagulants; the latter sludge was enriched in less reduced compounds. The precipitated phosphorus was not released to the supernatant during anaerobic digestion. No evidence for reduced digester stability was found for digestion of CEP-sludge. These results indicate that retro-fitting a plant by chemical pre-precipitation and subsequent anaerobic digestion of the CEP-sludge is a feasible option.

Grease biodegradation: is bioaugmentation more effective than natural populations for start-up?

1996 ◽  
Vol 34 (5-6) ◽  
pp. 303-308 ◽  
Author(s):  
Leopoldo Mendoza-Espinosa ◽  
Tom Stephenson
Keyword(s):  
Activated Sludge ◽  
Natural Populations ◽  
Oxygen Demand ◽  
Cod Removal ◽  
Batch Reactors ◽  
Optimum Conditions ◽  
Start Up ◽  
Degradation Rates ◽  
Activated Sludge Reactor ◽  
Micro Organisms

Investigations were undertaken in order to compare the grease degradation rates for a natural population of acclimatised activated sludge micro-organisms with a commercial bioaugmentation product (bioadditive) under optimum conditions in laboratory-scale batch reactors. Lard was chosen as the source of grease because it contains the fatty acids more commonly found in urban wastewaters. During acclimatisation, the bioadditive reactor achieved a slightly better chemical oxygen demand (COD) removal efficiency than the activated sludge reactor. Therefore, under optimum conditions, activated sludge was able to degrade grease at nearly the same rate as a bioadditive solution. Moreover, the bioadditive and the activated sludge reactors had very similar kinetics of COD removal under different grease concentrations. It was concluded that the use of natural activated sludge micro-organisms was sufficient to acclimatise biological processes to removing grease.

scholarly journals Mathematical models of anaerobic digestion for the treatment of swine effluents

2015 ◽  
Vol 45 (2) ◽  
pp. 172-179
Author(s):  
Daisa Stéfano Fagundes ◽  
Marco Antonio Previdelli Orrico Junior ◽  
Ana Carolina Amorim Orrico ◽  
Leonardo Oliveira Seno
Keyword(s):  
Anaerobic Digestion ◽  
Mathematical Models ◽  
Chemical Oxygen Demand ◽  
Solid Fraction ◽  
Methane Production ◽  
Oxygen Demand ◽  
Multivariate Models ◽  
High Confidence ◽  
Total Solids ◽  
Volatile Solids

ABSTRACT Pig breeding results in the production of large amounts of waste, which can cause serious environmental problems, when handled incorrectly. This study aimed at testing mathematical models to estimate the parameters of anaerobic biodigestion in biodigesters as a function of the composition of swine effluents with and without separation of the solid fraction and hydraulic retention times (HRT). Semi-continuous biodigesters fed with swine effluents with and without separation of the solid fraction and managed for 15, 22, 29 and 36 days of hydraulic retention were used. The potential of biogas and methane production, as well as the reduction of total solids, volatile solids and chemical oxygen demand, were assessed as a function of the effluents composition. HRT was the variable that most influenced the variation of the models, followed by the contents of total and volatile solids. Uni and multivariate models presented high confidence indices, being classified as “great” at predicting the potentials of biogas and methane production and “good” at predicting the reductions of total solids, volatile solids and chemical oxygen demand. The models obtained in this study can be used to reliably predict the parameters of the anaerobic biodigestion process of swine effluents in semi-continuous tubular biodigesters.

scholarly journals Laboratory-scale anaerobic sequencing batch reactor for treatment of stillage from fruit distillation

2013 ◽  
Vol 67 (5) ◽  
pp. 1068-1074 ◽  
Author(s):  
Elena Cristina Rada ◽  
Marco Ragazzi ◽  
Vincenzo Torretta
Keyword(s):  
Anaerobic Digestion ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Oxygen Demand ◽  
Gas Production ◽  
Design Parameters ◽  
Anaerobic Sequencing Batch Reactor ◽  
Reactor Technology ◽  
Volatile Solids ◽  
Experimental Apparatus

This work describes batch anaerobic digestion tests carried out on stillages, the residue of the distillation process on fruit, in order to contribute to the setting of design parameters for a planned plant. The experimental apparatus was characterized by three reactors, each with a useful volume of 5 L. The different phases of the work carried out were: determining the basic components of the chemical oxygen demand (COD) of the stillages; determining the specific production of biogas; and estimating the rapidly biodegradable COD contained in the stillages. In particular, the main goal of the anaerobic digestion tests on stillages was to measure the parameters of specific gas production (SGP) and gas production rate (GPR) in reactors in which stillages were being digested using ASBR (anaerobic sequencing batch reactor) technology. Runs were developed with increasing concentrations of the feed. The optimal loads for obtaining the maximum SGP and GPR values were 8–9 gCOD L−1 and 0.9 gCOD g−1 volatile solids.

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