Mesophilic Anaerobic Study on Chinese Herbs Residues of Honeysuckle and Midday Tea

2014 ◽  
Vol 878 ◽  
pp. 481-488
Author(s):  
Jun Hu Xu ◽  
Xiong Fei Chen ◽  
Lin Lin Mu ◽  
Hong Bo Zhang ◽  
Ya Fan Bi
Keyword(s):  
Methane Production ◽  
Solid Phase ◽  
Kinetic Constant ◽  
Maximum Yield ◽  
Anaerobic Treatment ◽  
Zero Order ◽  
Chinese Herbs ◽  
Anaerobic Sludge ◽  
Production Volume ◽  
Order Kinetic

A large number of Chinese herbs residues were produced during the production of honeysuckle and midday tea. Usually, the content of organic components in the residues was at a high level. These residues would pose a great threat to the local water environment, if they were not treated and disposed properly. In this paper, a self-prepared anaerobic reactor was utilized to treat the residues of honeysuckle and midday tea in semi-solid phase media. The anaerobic sludge was inoculated into the residues for anaerobic digestion at the temperature of 37±1°C, and ISRs (ISRs is the total solid mass ratio between inoculum and substrate) were 1:2, 1:1, 2:1 respectively. The result showed that the ultimate maximum yield of methane was the under ISRs of 1:1, the cumulative methane production volume of honeysuckle and midday tea dregs were 5832mL/100g and 5591mL/100g, respectively, after 192h digestion. Under the best inoculation ratio of 1:1, another mesophilic anaerobic experiment was carried out by mixing the residues of honeysuckle and midday tea as substrate at different ratios of 0:3, 1:2, 1:1, 2:1 and 3:0, respectively, which were to compare the methane production at 37±1°C. The result indicated that the ultimate maximum yield of methane was under mixed ratio of 1:2, the cumulative methane production volume of the mixed Chinese herbs residues was 9110 mL/100g after 192h digestion. Furthermore, the zero-order kinetic model was found to be suitable to characterize the removal ratio of substrate during 0~108h digestion while the biogas was generated fast, and the kinetic constant k was 50.49mL/h. To obtain the ultimate maximum rate of methane production, the anaerobic reaction should be controlled under the stage of zero-order reaction. Thus, the experimental results could provide scientific proof for anaerobic treatment and methane recycling in organic waste of Chinese herbs enterprises.

scholarly journals Kinetic analysis and simulation of UASB anaerobic treatment of a synthetic fruit wastewater

2013 ◽  
Vol 12 (2) ◽  
pp. 175-180 ◽  
Keyword(s):  
Kinetic Constant ◽  
Anaerobic Treatment ◽  
Uasb Reactor ◽  
Continuous Reactor ◽  
Anaerobic Sludge ◽  
Order Kinetic ◽  
First Order ◽  
Substrate Removal ◽  
Order Kinetic Model ◽  
Volumetric Loading

An Upflow Anaerobic Sludge Bed (UASB) reactor was used to evaluate mesophilic anaerobic treatment of a pre-acidified fruit wastewater. The system was operated at increasing volumetric loading rates by sequentially increasing wastewater flowrate. The operational temperature was maintained initially at 37 oC and consequently decreased to 30 and 25 oC. For the volumetric loading rates examined i.e. 5-35 KgCOD m-3d-1), the UASB attained COD removal levels higher than 70%. The first-order kinetics were found to be suitable for representation of the substrate removal. The kinetic constant decreased from 23 to 21 and 19 d-1 at 37, 30 and 25 oC respectively. Prediction of effluent COD and methane production rate during continuous reactor operation was possible using the first-order kinetic model.

Comparison of the biodegradability of the grey fraction of municipal solid waste of Barcelona in mesophilic and thermophilic conditions

2003 ◽  
Vol 48 (4) ◽  
pp. 21-28 ◽  
Author(s):  
S. Mace ◽  
D. Bolzonella ◽  
F. Cecchi ◽  
J. Mata-Alvarez
Keyword(s):  
Kinetic Study ◽  
Methane Production ◽  
Kinetic Constant ◽  
Order Kinetic ◽  
Organic Loading ◽  
First Order ◽  
Loading Rates ◽  
Start Up ◽  
Constant Operation ◽  
Thermophilic Conditions

The results of the start-up of two digesters in mesophilic and thermophilic conditions, together with its steady results at several organic loading rates are described. A kinetic study is also carried out which allows one to estimate the ultimate methane production, together with the first-order kinetic constant. Operation at thermophilic temperature yields better results as it allows a more loaded reactor and the methane production is slightly higher.

scholarly journals Hydrocarbon Toxicity towards Hydrogenotrophic Methanogens in Oily Waste Streams

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4830
Author(s):  
Bruno P. Morais ◽  
Valdo Martins ◽  
Gilberto Martins ◽  
Ana Rita Castro ◽  
Maria Madalena Alves ◽  
...  
Keyword(s):  
Methane Production ◽  
Complex Mixture ◽  
Anaerobic Treatment ◽  
Anaerobic Sludge ◽  
Oily Sludge ◽  
Waste Streams ◽  
Energy Potential ◽  
Methanogenic Activity ◽  
Hydrogenotrophic Methanogens ◽  
Oily Waste

Hydrocarbon-containing wastes and wastewaters are produced worldwide by the activities of the oil and gas industry. Anaerobic digestion has the potential to treat these waste streams, while recovering part of its energy potential as biogas. However, hydrocarbons are toxic compounds that may inhibit the microbial processes, and particularly the methanogens. In this work, the toxicity of hexadecane (0–30 mM) towards pure cultures of hydrogenotrophic methanogens (Methanobacterium formicicum and Methanospirillum hungatei) was assessed. Significantly lower (p < 0.05) methane production rates were only verified in the incubations with more than 15 mM hexadecane and represented up to 52% and 27% inhibition for M. formicicum and M. hungatei, respectively. The results obtained point out that 50% inhibition of the methanogenic activity would likely occur at hexadecane concentrations between 5–15 mM and >30 mM for M. formicicum and M. hungatei, respectively, suggesting that toxic effects from aliphatic hydrocarbons towards hydrogenotrophic methanogens may not occur during anaerobic treatment. Hydrocarbon toxicity towards hydrogenotrophic methanogens was further assessed by incubating an anaerobic sludge with H2/CO2 in the presence of a complex mixture of hydrocarbons (provided by the addition of an oily sludge from a groundwater treatment system). Specific methanogenic activity from H2/CO2 decreased 1.2 times in the presence of the hydrocarbons, but a relatively high methane production (~30 mM) was still obtained in the assays containing the inoculum and the oily sludge (without H2/CO2), reinforcing the potential of anaerobic treatment systems for methane production from oily waste/wastewater.

Sodium hydroxide pretreatment of ensiled sorghum forage and wheat straw to increase methane production

2012 ◽  
Vol 66 (11) ◽  
pp. 2447-2452 ◽  
Author(s):  
C. Sambusiti ◽  
E. Ficara ◽  
M. Rollini ◽  
M. Manzoni ◽  
F. Malpei
Keyword(s):  
Sodium Hydroxide ◽  
Wheat Straw ◽  
Methane Production ◽  
Kinetic Constant ◽  
Oxygen Demand ◽  
Order Kinetic ◽  
Naoh Pretreatment ◽  
Naoh Solution ◽  
Anaerobic Degradability ◽  
Ensiled Sorghum Forage

The aim of this study was to determine the effect of sodium hydroxide pretreatment on the chemical composition and the methane production of ensiled sorghum forage and wheat straw. NaOH pretreatment was conducted in closed bottles, at 40 °C for 24 h. Samples were soaked in a NaOH solution at different dosages (expressed in terms of total solids (TS) content) of 1 and 10% gNaOH/gTS, with a TS concentration of 160 gTS/L. At the highest NaOH dosage the reduction of cellulose, hemicelluloses and lignin was 31, 66 and 44%, and 13, 45 and 3% for sorghum and wheat straw, respectively. The concentration of soluble chemical oxygen demand (CODs) in the liquid phase after the pretreatment was also improved both for wheat straw and sorghum (up to 24 and 33%, respectively). Total sugars content increased up to five times at 10% gNaOH/gTS with respect to control samples, suggesting that NaOH pretreatment improves the hydrolysis of cellulose and hemicelluloses. The Biochemical Methane Potential (BMP) tests showed that the NaOH pretreatment favoured the anaerobic degradability of both substrates. At 1 and 10% NaOH dosages, the methane production increased from 14 to 31% for ensiled sorghum forage and from 17 to 47% for wheat straw. The first order kinetic constant increased up to 65% for sorghum and up to 163% for wheat straw.

Inhibition of methanogenic activity of starch-degrading granules by aromatic pollutants

1997 ◽  
Vol 35 (8) ◽  
pp. 247-253 ◽  
Author(s):  
Herbert H. P. Fang ◽  
Ivan W. C. Lau ◽  
Denis W. C. Chung
Keyword(s):  
Chemical Industry ◽  
Functional Group ◽  
Anaerobic Treatment ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Aromatic Pollutants ◽  
Methanogenic Activity ◽  
Phenolic Pollutants ◽  
Ic50 Values

The effects of nine common aromatic pollutants from chemical industry on the bioactivity of anaerobic granules were examined. The granules were obtained from an upflow anaerobic sludge blanket (UASB) reactor treating wastewater containing colloidal starch. The specific methanogenic activities (SMA) of granules were measured at 37°C in serum vials using 3000 mg/l of colloidal starch as substrate, plus individual pollutants at various concentrations. The toxicity was expressed by the IR50 and IC50 values, i.e. the toxicant/biomass ratio and concentration at which levels the granules exhibited only 50% of their original bioactivities. Results showed that in general the granules exhibited mild resistance to toxicity of aromatic pollutants, probably due to the granules' layered microstructure. The toxicities, which were dependent on the nature of chemical functional group, of the aromatic pollutants were in the following descending order: cresols &gt; phenol &gt; hydroxyphenols/phthalate &gt; benzoate. There was only marginal difference between the toxicity of the steric isomers. For the seven phenolic pollutants, the more hydrophobic the functional group the higher the toxicity. The granules' resistance to toxicity suggested the plausibility of anaerobic treatment of wastewater from the chemical industry.

scholarly journals Enhancing methane production from the invasive macroalga Rugulopteryx okamurae through anaerobic co-digestion with olive mill solid waste: process performance and kinetic analysis

2021 ◽  
Author(s):  
D. de la Lama-Calvente ◽  
M. J. Fernández-Rodríguez ◽  
J. Llanos ◽  
J. M. Mancilla-Leytón ◽  
R. Borja
Keyword(s):  
Anaerobic Digestion ◽  
Solid Waste ◽  
Methane Production ◽  
Methane Yield ◽  
Specific Rate ◽  
Order Kinetic ◽  
Two Phase ◽  
First Order ◽  
Olive Mill Solid Waste ◽  
Olive Mill

AbstractThe biomass valorisation of the invasive brown alga Rugulopteryx okamurae (Dictyotales, Phaeophyceae) is key to curbing the expansion of this invasive macroalga which is generating tonnes of biomass on southern Spain beaches. As a feasible alternative for the biomass management, anaerobic co-digestion is proposed in this study. Although the anaerobic digestion of macroalgae barely produced 177 mL of CH4 g−1 VS, the co-digestion with a C-rich substrate, such as the olive mill solid waste (OMSW, the main waste derived from the two-phase olive oil manufacturing process), improved the anaerobic digestion process. The mixture improved not only the methane yield, but also its biodegradability. The highest biodegradability was found in the mixture 1 R. okamurae—1 OMSW, which improved the biodegradability of the macroalgae by 12.9% and 38.1% for the OMSW. The highest methane yield was observed for the mixture 1 R. okamurae—3 OMSW, improving the methane production of macroalgae alone by 157% and the OMSW methane production by 8.6%. Two mathematical models were used to fit the experimental data of methane production time with the aim of assessing the processes and obtaining the kinetic constants of the anaerobic co-digestion of different combination of R. okamurae and OMSW and both substrates independently. First-order kinetic and the transference function models allowed for appropriately fitting the experimental results of methane production with digestion time. The specific rate constant, k (first-order model) for the mixture 1 R. okamurae- 1.5 OMSW, was 5.1 and 1.3 times higher than that obtained for the mono-digestion of single OMSW and the macroalga, respectively. In the same way, the transference function model revealed that the maximum methane production rate (Rmax) was also found for the mixture 1 R. okamurae—1.5 OMSW (30.4 mL CH4 g−1 VS day−1), which was 1.6 and 2.2 times higher than the corresponding to the mono-digestions of the single OMSW and sole R. okamurae (18.9 and 13.6 mL CH4 g−1 VS day−1), respectively.

scholarly journals Evaluation of acidogenesis products’ effect on biogas production performed with metagenomics and isotopic approaches

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Anna Detman ◽  
Michał Bucha ◽  
Laura Treu ◽  
Aleksandra Chojnacka ◽  
Łukasz Pleśniak ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Methane Production ◽  
Bacterial Species ◽  
Stable Carbon Isotope ◽  
Anaerobic Sludge ◽  
Methane Formation ◽  
Microbial Composition ◽  
Fermentation Products ◽  
Core Microbiome ◽  
Specific Species

Abstract Background During the acetogenic step of anaerobic digestion, the products of acidogenesis are oxidized to substrates for methanogenesis: hydrogen, carbon dioxide and acetate. Acetogenesis and methanogenesis are highly interconnected processes due to the syntrophic associations between acetogenic bacteria and hydrogenotrophic methanogens, allowing the whole process to become thermodynamically favorable. The aim of this study is to determine the influence of the dominant acidic products on the metabolic pathways of methane formation and to find a core microbiome and substrate-specific species in a mixed biogas-producing system. Results Four methane-producing microbial communities were fed with artificial media having one dominant component, respectively, lactate, butyrate, propionate and acetate, for 896 days in 3.5-L Up-flow Anaerobic Sludge Blanket (UASB) bioreactors. All the microbial communities showed moderately different methane production and utilization of the substrates. Analyses of stable carbon isotope composition of the fermentation gas and the substrates showed differences in average values of δ13C(CH4) and δ13C(CO2) revealing that acetate and lactate strongly favored the acetotrophic pathway, while butyrate and propionate favored the hydrogenotrophic pathway of methane formation. Genome-centric metagenomic analysis recovered 234 Metagenome Assembled Genomes (MAGs), including 31 archaeal and 203 bacterial species, mostly unknown and uncultivable. MAGs accounted for 54%–67% of the entire microbial community (depending on the bioreactor) and evidenced that the microbiome is extremely complex in terms of the number of species. The core microbiome was composed of Methanothrix soehngenii (the most abundant), Methanoculleus sp., unknown Bacteroidales and Spirochaetaceae. Relative abundance analysis of all the samples revealed microbes having substrate preferences. Substrate-specific species were mostly unknown and not predominant in the microbial communities. Conclusions In this experimental system, the dominant fermentation products subjected to methanogenesis moderately modified the final effect of bioreactor performance. At the molecular level, a different contribution of acetotrophic and hydrogenotrophic pathways for methane production, a very high level of new species recovered, and a moderate variability in microbial composition depending on substrate availability were evidenced. Propionate was not a factor ceasing methane production. All these findings are relevant because lactate, acetate, propionate and butyrate are the universal products of acidogenesis, regardless of feedstock.

scholarly journals Pretreatment, Anaerobic Codigestion, or Both? Which Is More Suitable for the Enhancement of Methane Production from Agricultural Waste?

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4175
Author(s):  
Lütfiye Dumlu ◽  
Asli Seyhan Ciggin ◽  
Stefan Ručman ◽  
N. Altınay Perendeci
Keyword(s):  
Anaerobic Digestion ◽  
Methane Production ◽  
Agricultural Waste ◽  
Kinetic Studies ◽  
Antagonistic Effect ◽  
Hydrolysis Rate ◽  
Order Kinetic ◽  
Maximum Enhancement ◽  
Mixing Ratios ◽  
Anaerobic Codigestion

Pretreatment and codigestion are proven to be effective strategies for the enhancement of the anaerobic digestion of lignocellulosic residues. The purpose of this study is to evaluate the effects of pretreatment and codigestion on methane production and the hydrolysis rate in the anaerobic digestion of agricultural wastes (AWs). Thermal and different thermochemical pretreatments were applied on AWs. Sewage sludge (SS) was selected as a cosubstrate. Biochemical methane potential tests were performed by mixing SS with raw and pretreated AWs at different mixing ratios. Hydrolysis rates were estimated by the best fit obtained with the first-order kinetic model. As a result of the experimental and kinetic studies, the best strategy was determined to be thermochemical pretreatment with sodium hydroxide (NaOH). This strategy resulted in a maximum enhancement in the anaerobic digestion of AWs, a 56% increase in methane production, an 81.90% increase in the hydrolysis rate and a 79.63% decrease in the technical digestion time compared to raw AWs. On the other hand, anaerobic codigestion (AcoD) with SS was determined to be ineffective when it came to the enhancement of methane production and the hydrolysis rate. The most suitable mixing ratio was determined to be 80:20 (Aws/SS) for the AcoD of the studied AWs with SS in order to obtain the highest possible methane production without any antagonistic effect.

scholarly journals A Study on the Feasibility of Anaerobic Co-Digestion of Raw Cheese Whey with Coffee Pulp Residues

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3611
Author(s):  
Sandra Gonzalez-Piedra ◽  
Héctor Hernández-García ◽  
Juan M. Perez-Morales ◽  
Laura Acosta-Domínguez ◽  
Juan-Rodrigo Bastidas-Oyanedel ◽  
...  
Keyword(s):  
Methane Production ◽  
Kinetic Models ◽  
Cheese Whey ◽  
Maximum Yield ◽  
Gompertz Model ◽  
Coffee Pulp ◽  
The One ◽  
The Cost ◽  
Best Fit ◽  
Cheese Production

In this paper, a study on the feasibility of the treatment of raw cheese whey by anaerobic co-digestion using coffee pulp residues as a co-substrate is presented. It considers raw whey generated in artisanal cheese markers, which is generally not treated, thus causing environmental pollution problems. An experimental design was carried out evaluating the effect of pH and the substrate ratio on methane production at 35 °C (i.e., mesophilic conditions). The interaction of the parameters on the co-substrate degradation and the methane production was analyzed using a response surface analysis. Furthermore, two kinetic models were proposed (first order and modified Gompertz models) to determine the dynamic profiles of methane yield. The results show that co-digestion of the raw whey is favored at pH = 6, reaching a maximum yield of 71.54 mLCH4 gVSrem−1 (31.5% VS removed) for raw cheese whey and coffee pulp ratio of 1 gVSwhey gVSCoffe−1. The proposed kinetic models successfully fit the experimental methane production data, the Gompertz model being the one that showed the best fit. Then, the results show that anaerobic co-digestion can be used to reduce the environmental impact of raw whey. Likewise, the methane obtained can be integrated into the cheese production process, which could contribute to reducing the cost per energy consumption.

The joint acute effect of tetracycline, erythromycin and sulfamethoxazole on acetoclastic methanogens

2015 ◽  
Vol 71 (8) ◽  
pp. 1128-1135 ◽  
Author(s):  
Sevcan Aydın ◽  
Bahar Ince ◽  
Orhan Ince
Keyword(s):  
Mrna Level ◽  
Acute Effect ◽  
Anaerobic Treatment ◽  
Anaerobic Sludge ◽  
Batch Reactors ◽  
Sequencing Batch Reactors ◽  
Acetyl Coa ◽  
Acetate Accumulation ◽  
Acetate Degradation ◽  
Industry Wastewater

In this study, we aimed to develop an understanding of the triple effects of sulfamethoxazole–erythromycin–tetracycline (ETS) and the dual effects of sulfamethoxazole–tetracycline (ST), erythromycin–sulfamethoxazole (ES) and erythromycin–tetracycline (ET) on the anaerobic treatment of pharmaceutical industry wastewater throughout a year of operation. Concentrations of the antibiotics in the influent were gradually increased until the metabolic collapse of the anaerobic sequencing batch reactors (SBRs), which corresponded to ETS (40 + 3 + 3 mg/L) and ST (25 + 2.5 mg/L), ET (4 + 4 mg/L) and ES (3 + 40 mg/L). Acetate accumulation in the anaerobic SBRs, acetoclastic activity of the anaerobic sludge taken from different antibiotic feeding stages and also expression of acetyl-coA synthetase from the acetoclastic methanogenic pathway on the mRNA level were assessed. The results indicated that, while acetate accumulation and decrease of acetoclastic activity were observed after stage 3 in the ST and ES reactors, and stage 7 in the ETS and ET reactors, the expression of acetyl-coA synthetase was mostly decreased in the last stages in all SBRs, in which antibiotic mixture feeding was terminated. It might be speculated that acetoclastic methanogens have an important role in acetate degradation by expressing acetyl-coA synthetase.

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