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1.
Waste Manag ; 102: 939-948, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31855694

RESUMO

With the purpose of developing a novel approach of agricultural waste treatment and overcoming bottlenecks for upscaling solid-state fermentation processes, the type of aerated, continuously stirred solid-state bioreactors were used for the production of γ-PGA by Bacillus amyloliquefaciens JX-6. Using corn stalk and soybean meal, the most common agricultural waste in China, as solid substrates, the maximum production of γ-PGA was 116.88 ± 5.05 g/kg and 102.48 ± 3.30 g/kg in 50 L and 150 L bioreactors, respectively. Production of γ-PGA in 50 L bioreactor was higher than in 150 L bioreactor, demonstrating that a reduction in γ-PGA production occurred as the fermentation system enlarged. An analysis of the interactions among fermentation parameters (temperature, moisture, and pH), γ-PGA production, solid substrates and bacterial communities indicated that different bioreactor capacities caused changes in fermentation parameters and bacterial communities, which in turn affected substrate utilization and γ-PGA production. Overall, obtaining considerable amounts of γ-PGA under non-sterilized fermentation expressed that JX-6 has excellent abilities to adapt to these substrates and conditions. Bioconversion of agricultural waste into γ-PGA in scale-up fermentation was successfully conducted by creating a more stable and suitable fermentation environment in bioreactors.


Assuntos
Reatores Biológicos , Ácido Poliglutâmico , China , Fermentação , Ácido Poliglutâmico/análogos & derivados
2.
Bioresour Technol ; 293: 122066, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31557641

RESUMO

This work investigated the effects of different temperatures on methane production, kinetics, and microbial communities during solid-state anaerobic digestion (SS-AD) using rice straw. The results indicated that thermophilic anaerobic digestion led to the faster methane production (13.74 L/kg) and a shorter biogas production cycle (34 days) than mesophilic anaerobic digestion (5.48 L/kg, 58 days). SS-AD under thermophilic conditions resulted in more intense lignocellulose degradation and better fitting results. The species of microorganisms did not differ when the temperature was altered; however, the abundances of various phyla, particularly Firmicutes, differed. Overall, the findings suggested that thermophilic SS-AD had higher methanogenic efficiency and dramatically altered the structure of the microbial community during solid-state anaerobic digestion. Moreover, a potential effective strategy for agricultural waste management by SS-AD was proposed.


Assuntos
Biocombustíveis , Oryza , Anaerobiose , Reatores Biológicos , Metano , Temperatura Ambiente
3.
Chem Commun (Camb) ; 55(76): 11410-11413, 2019 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-31482869

RESUMO

Graphene-based composite materials are versatile but not easily procurable. Cyanobacterial cells, an outgrowth of eutrophic freshwater lake, were simultaneously employed as a template for the growth of ZnO nanoparticles and as a biomass carbon source for graphene sheets, resulting in chlorophyll-containing graphene-wrapped ZnO nanospheres.


Assuntos
Cianobactérias/química , Cianobactérias/citologia , Grafite/química , Nanosferas/química , Óxido de Zinco/química , Clorofila/química
4.
Chemosphere ; 234: 260-268, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31220659

RESUMO

Phenolic compounds are problematic byproducts generated from lignocellulose pretreatment. In this study, the feasibility degradation of syringic acid (SA), vanillic acid (VA), and 4-hydroxybenzoic acid (HBA) by Bio-Electro-Fenton (BEF) system with a novel Fe-Mn/graphite felt (Fe-Mn/GF) composite cathode were investigated. The nano-scale Fe-Mn multivalent composite catalyst with core shell structure distributed more evenly on GF surface to form a catalyst layer with higher oxygen reduction reaction performance. Accordingly, the maximum power density generated with Fe-Mn/GF cathode was 48.1% and 238.9% higher than Fe/GF and GF respectively, which further enhanced the in situ generation of H2O2 due to the superiority of nano-scale core shell structure and synergistic effect of Fe and Mn species. The degradation efficiency of the three phenolic compounds in the BEF system could reached 100% after optimization of influencing parameters. Furthermore, a possible SA degradation pathway by BEF process in the present system was proposed based on the detected intermediates. These results demonstrated an efficient approach for the degradation of phenolic compounds derived from lignocellulose hydrolysates.


Assuntos
Eletroquímica , Eletrodos , Grafite/química , Peróxido de Hidrogênio , Ferro/química , Manganês/química , Fenóis/química , Catálise
5.
Nanomaterials (Basel) ; 9(5)2019 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-31060270

RESUMO

N-doped TiO2 with oxygen vacancies exhibits many advantages for photocatalysis, such as enhanced visible light absorbency, inhibition of the photogenerated charge carrier recombination, etc. However, preparation of N-doped TiO2 with oxygen vacancies under mild conditions is still a challenge. Herein, N-doped TiO2 nanospheres with tetrahedral Ti4+ sites were synthesized by using dodecylamine as template and assisted by l-alanine acids. The obtained samples were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and UV-Vis diffuse reflectance spectra (UV-Vis DRS). It was found that the dodecylamine as a neutral surfactant controlled the structure of TiO2 spherical, while l-alanine acids provided a nitrogen source. The existence of tetrahedral Ti4+ sites in N-doped TiO2 was also confirmed. The N-doped TiO2 sample with tetrahedral Ti4+ sites exhibited significantly improved photocatalytic performance for degradation of methylene blue solution under UV light or visible light irradiation. A combined time-resolved infrared (IR) spectroscopy study reveals that the enhanced photocatalytic performance could be attributed to a large amount of photogenerated charge carriers and efficient charge separation. It is demonstrated that the shallow donor state produced by oxygen vacancies of tetrahedral Ti4+ sites can effectively promote separation of charge carriers besides capturing electrons.

6.
J Biotechnol ; 298: 1-4, 2019 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-30974118

RESUMO

Adenosine, which is produced mainly by microbial fermentation, plays an important role in the therapy of cardiovascular disease and has been widely used as an antiarrhythmic agent. In this study, guanosine 5'-monophosphate (GMP) synthetase gene (guaA) was inactivated by gene-target manipulation to increase the metabolic flux from inosine 5'-monophosphate (IMP) to adenosine in B. subtilis A509. The resulted mutant M3-3 showed an increased adenosine production from 7.40 to 10.45 g/L, which was further enhanced to a maximum of 14.39 g/L by central composite design. As the synthesis of succinyladenosine monophosphate (sAMP) from IMP catalysed by adenylosuccinate synthetase (encoded by purA gene) is the rate-limiting step in adenosine synthesis, the up-regulated transcription level of purA was the potential underlying mechanism for the increased adenosine production. This work demonstrated a practical strategy for breeding B. subtilis strains for industrial nucleoside production.


Assuntos
Adenosina/genética , Adenilossuccinato Sintase/genética , Bacillus subtilis/genética , Carbono-Nitrogênio Ligases/genética , Adenosina/biossíntese , Monofosfato de Adenosina/análogos & derivados , Monofosfato de Adenosina/genética , Carbono-Nitrogênio Ligases/antagonistas & inibidores , Fermentação , Marcação de Genes , Inosina/genética , Inosina/metabolismo , Inosina Monofosfato/genética , Mutagênese Sítio-Dirigida , Mutação/genética
7.
Nanomaterials (Basel) ; 8(11)2018 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-30441829

RESUMO

In sharp contrast to conventional photosensitization methods in which the organic pigments were often adsorbed, herein we present a study on natural vegetable pigment inserted TiO2 aerogel nanocomposites and we directly use red cabbage anthocyanin (RCP) as a structure-directing agent. It was found that pure TiO2 aerogel nanocomposite did not exhibit any meaningful activity for photocatalytic reduction of Cr(VI). However, the photocatalytic reduction activity was greatly improved by the RCP inserted TiO2 aerogel nanocomposites under visible-light irradiation, which was approximately 2- and 12.3-fold higher than that of TiO2 aerogel conventionally photosensitized by RCP and pure TiO2 aerogel nanocomposites, respectively. It also exhibited good stability and could be reused at least three times without losing a significant amount of its activity.

8.
Bioresour Technol ; 248(Pt A): 265-271, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28651869

RESUMO

The aim of this work was to study the acetate separation from fresh vinegar residue (FVR) to avoid inhibition of methanogenesis and hydrothermal treatment on washed vinegar residue (WVR) to enhance methane production. The optimal liquid-solid ratio was 10:1mL/g for the washing of FVR. The methane yields of the FVR, WVR, and washed leachate (WL) were 273L/kgVS, 199L/kgVS, and 306.9L/kgCOD, respectively. The optimal hydrothermal temperature was 160°C for WVR, with maximum methane yield of 258.38L/kgVS. Hydrothermal pretreatment destroyed the structure of lignocellulose and improved the hydrolysis of hemicellulose. Compared with thermophilic digestion of FVR, thermophilic digestion of 160°C treated FVR, and thermophilic digestion of WVR with mesophilic digestion of WL, the thermophilic digestion of 160°C treated WVR with mesophilic digestion of WL obtained the maximum total methane yield of 102.5L/kgFVR.


Assuntos
Ácido Acético , Anaerobiose , Reatores Biológicos , Hidrólise , Metano , Temperatura Ambiente
9.
Bioresour Technol ; 245(Pt A): 90-97, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28892710

RESUMO

In order to elucidate the instability mechanism, screen early warning indicators, and propose control measures, the mesophilic digestion of vegetable waste (VW) was carried out at organic loading rates (OLR) of 0.5, 1.0, and 1.5g volatile solid (VS)/(Ld). The process parameters, including biogas components, volatile fatty acids (VFA), ammonia, pH, total alkalinity (TA), bicarbonate alkalinity (BA), and intermediate alkalinity (IA), were monitored every day. Digestion was inhibited at OLR of 1.5gVS/(Ld). The primary causes of instability are a high sugar and negligible ammonia content, in addition to the feed without effluent recirculation, which led to BA loss. The ratios of CH4/CO2, VFA/BA, propionate, n-butyrate and iso-valerate were selected as early warning indicators. In order to maintain the digestion of VW at a high OLR, control measures including effluent recirculation and trace element addition are recommended.


Assuntos
Biocombustíveis , Reatores Biológicos , Verduras , Anaerobiose , Ácidos Graxos Voláteis , Metano
10.
Bioresour Technol ; 241: 1191-1196, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28647320

RESUMO

Microbial fuel cell (MFC) is a promising device for energy generation and organic waste treatment simultaneously by electrochemically active bacteria (EAB). In this study, an integrated aerobic-anaerobic strategy was developed to improve the performance of P. aeruginosa-inoculated MFC. With an aerobic start-up and following an anaerobic discharge process, the current density of MFC reached a maximum of 99.80µA/cm2, which was 91.6% higher than the MFC with conventional constant-anaerobic operation. Cyclic voltammetry and HPLC analysis showed that aerobic start-up significantly increased electron shuttle (pyocyanin) production (76% higher than the constant-anaerobic MFC). Additionally, enhanced anode biofilm formation was also observed in the integrated aerobic-anaerobic MFC. The increased pyocyanin production and biofilm formation promoted extracellular electron transfer from EAB to the anode and were the underlying mechanism for the MFC performance enhancement. This work demonstrated the integrated aerobic-anaerobic strategy would be a practical strategy to enhance the electricity generation of MFC.


Assuntos
Fontes de Energia Bioelétrica , Pseudomonas aeruginosa , Eletricidade , Eletrodos , Piocianina
11.
J Hazard Mater ; 324(Pt B): 178-183, 2017 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-28340989

RESUMO

The intensive use of triphenyltin chloride (TPTC) has caused serious environmental pollution. In this study, an effective method for TPTC degradation was proposed based on the Bio-Electron-Fenton process in microbial fuel cells (MFCs). The maximum voltage of the MFC with graphite felt as electrode was 278.47% higher than that of carbon cloth. The electricity generated by MFC can be used for in situ generation of H2O2 to a maximum of 135.96µmolL-1 at the Fe@Fe2O3(*)/graphite felt composite cathode, which further reacted with leached Fe2+ to produce hydroxyl radicals. While 100µmolL-1 TPTC was added to the cathodic chamber, the degradation efficiency of TPTC reached 78.32±2.07%, with a rate of 0.775±0.021µmolL-1h-1. This Bio-Electron-Fenton driving TPTC degradation might involve in SnC bonds breaking and the main process is probably a stepwise dephenylation until the formation of inorganic tin and CO2. This study provides an energy saving and efficient approach for TPTC degradation.


Assuntos
Fontes de Energia Bioelétrica , Peróxido de Hidrogênio/química , Ferro/química , Compostos Orgânicos de Estanho/química , Poluentes Químicos da Água/química , Técnicas Eletroquímicas , Purificação da Água/métodos
12.
Huan Jing Ke Xue ; 38(6): 2607-2616, 2017 Jun 08.
Artigo em Chinês | MEDLINE | ID: mdl-29965384

RESUMO

In order to improve the methane production and concentration, effect of activated carbon addition on the anaerobic fermentation of corn straw under the conditions of mesophilic temperature (38℃) and thermophilic temperature(50℃) was investigated in this study. The results showed that the addition of activated carbon could significantly promote methane production. Compared with the control group in mesophilic and thermophilic conditions, cumulative methane production could be increased by 63% and 96% in test groups. By DGGE analysis, the bacterium enriched by addition of activated carbon was mainly Clostridiales bacterium, compared to Bacillus (without adding activated carbon) in the thermophilic system, while the differences in fermentation with adding activated carbon and without adding activated carbon was not significant in the mesophilic system. With addition of activated carbon, the archaea enriched in the fermentation liquid was mainly Methanosaeta concilii in the mesophilic system, whereas the archaea enriched in the fermentation liquid was mainly Methanosarcina acetivorans in the thermophilic system. The archaea enriched on activated carbon was mainly Methanosaeta concilii at mesophilic temperature, while the archaea enriched on activated carbon was mainly Methanosarcina thermophila at thermophilic temperature.


Assuntos
Reatores Biológicos/microbiologia , Carvão Vegetal/química , Fermentação , Metano/biossíntese , Zea mays , Anaerobiose , Archaea , Bactérias , Temperatura Ambiente
13.
Bioresour Technol ; 225: 23-33, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27875765

RESUMO

Anaerobic co-digestion is considered to be an efficient way to improve the biogas production. The abundance, dynamic and interactional networks of prokaryotic community were investigated between co-digestion and mono-digestions of corn stalk and pig manure in mesophilic batch test. Co-digestion showed higher methane production, and contributed to suitable microenvironment as well as stable prokaryotic community structure. The highest methane production was achieved with the highest relative abundance of Methanosaeta. Prokaryotic community in mono-digestions might inhibited by FA or FVFA. The functional modules in co-digestion and mono-digestion of pig manure clustered together with bigger size and higher degree, and the connections of metabolic functions were better-organized, which means high-efficient utilization of substrate and prevention of the two digestion systems crash. The partial mantel tests showed the functional modules were significantly affected by environmental factors. These results further explained that why co-digestion was more efficient than mono-digestion owing to suitable microenvironment.


Assuntos
Esterco/microbiologia , Células Procarióticas/metabolismo , Eliminação de Resíduos/métodos , Zea mays/química , Animais , Biocombustíveis/microbiologia , Reatores Biológicos/microbiologia , Ácidos Graxos Voláteis/análise , Concentração de Íons de Hidrogênio , Cinética , Metano/biossíntese , Nitrogênio/análise , Análise de Componente Principal , Estatísticas não Paramétricas , Sus scrofa
14.
J Environ Sci (China) ; 42: 210-214, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27090713

RESUMO

The anaerobic digestion (AD) and microbial electrolysis cell (MEC) coupled system has been proved to be a promising process for biomethane production. In this paper, it was found that by co-cultivating Geobacter with Methanosarcina in an AD-MEC coupled system, methane yield was further increased by 24.1%, achieving to 360.2 mL/g-COD, which was comparable to the theoretical methane yield of an anaerobic digester. With the presence of Geobacter, the maximum chemical oxygen demand (COD) removal rate (216.8 mg COD/(L·hr)) and current density (304.3A/m(3)) were both increased by 1.3 and 1.8 fold compared to the previous study without Geobacter, resulting in overall energy efficiency reaching up to 74.6%. Community analysis demonstrated that Geobacter and Methanosarcina could coexist together in the biofilm, and the electrochemical activities of both were confirmed by cyclic voltammetry. Our study observed that the carbon dioxide content in total gas generated from the AD reactor with Geobacter was only half of that generated from the same reactor without Geobacter, suggesting that Methanosarcina may obtain the electron transferred from Geobacter for the reduction of carbon dioxide to methane. Taken together, Geobacter not only can improve the performance of the MEC system, but also can enhance methane production.


Assuntos
Fontes de Energia Bioelétrica , Geobacter/fisiologia , Metano/metabolismo , Methanosarcina/fisiologia , Anaerobiose , Análise da Demanda Biológica de Oxigênio , Dióxido de Carbono , Eletrólise
15.
Appl Biochem Biotechnol ; 179(5): 846-62, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26940572

RESUMO

To investigate the effects of organic loading rate (OLR) on performance and stability of mesophilic co-digestion of rice straw (RS) and chicken manure (CM), benchtop experiments (40 L) were carried out at OLRs of 3.0, 3.6, 4.2, 4.8, 6.0, 8.0, and 12.0 kg volatile solid (VS)/(m(3)·day) with volatile solid (VS) ratio of 1:1 (RS/CM) which was based on batch tests. Anaerobic co-digestion was slightly and severely inhibited by the accumulation of ammonia when the digester was overloaded at an OLR of 6 and 12 kg VS/(m(3)·day), respectively. The recommended OLR for co-digestion is 4.8 kg VS/(m(3)·day), which corresponds to average specific biogas production (SBP) of 380 L/kg VS and volumetric biogas production rate (VBPR) of 1.8 m(3)/(m(3)·day). An OLR of 6-8 kg VS/(m(3)·d) with SBP of 360-440 L/kg VS and VBPR of 2.1-3.5 m(3)/(m(3)·day) could be considered, if an Anaerobic digestion (AD) system assisted by in situ removal of ammonia was adopted.


Assuntos
Amônia/química , Biocombustíveis , Esterco/análise , Oryza/química , Anaerobiose , Animais , Galinhas , Metano/química
16.
J Biotechnol ; 223: 6-7, 2016 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-26916414

RESUMO

Cryptococcus albidus NT2002, isolated from the soil in Xinjiang, China, appeared to have the ability to accumulate microbial lipid by utilizing various carbon sources. The predominant properties make it as a potential bio-platform for biodiesel production. Here, we report the complete genome sequence of C. albidus NT2002, which might provide a basis for further elucidation of the genetic background of this promising strain for developing metabolic engineering strategies to produce biodiesel in a green and sustainable manner.


Assuntos
Cryptococcus/genética , Genoma Fúngico , Análise de Sequência de DNA/métodos , Composição de Bases , Tamanho do Genoma , Engenharia Metabólica , Microbiologia do Solo
17.
J Air Waste Manag Assoc ; 66(4): 420-8, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26828620

RESUMO

UNLABELLED: Odor pollution is a big environmental problem caused by large-scale livestock production in China, and developing a practical way to reduce these odors is pressing. In this study, a combination of 0.2-1.0 U/mL lignin peroxidase (LiP) and one of three peroxides (H2O2, CaO2, 2Na3CO3·3H2O2) was examined for its efficiency in reducing the release of eight chemicals (propionic acid, isobutyric acid, isocaproic acid, isovaleric acid, phenol, p-cresol, indole, and skatole), NH3, H2S, and odor intensity from pig manure. The results showed an approximately 90% reduction in p-cresol, 40-60% reduction in odor intensity, 16.5-40% reduction in indolic compounds, and 25-40% reduction in volatile fatty acids. Being the electron acceptors of LiP, 2Na3CO3·3H2O2 and CaO2 performed better than H2O2 in reducing the concentration of eight chemicals, NH3, H2S, and odor intensity from pig manure. The effect of deodorization can last for up to 72 hr. IMPLICATIONS: In China, one of the major environmental problems caused by confined feeding is odor pollution, which brings a major threat to the sustainability, profitability, and growth of the livestock industry. To couple the LiP with the electron acceptors, a low-cost, simple, and feasible method for odor removal was established in this study. Based on the study results, a practical treatment method was provided for odor pollution and supply the farm operators a more flexible time to dispose treated manure.


Assuntos
Esterco , Odorantes/prevenção & controle , Peroxidases/metabolismo , Peróxidos/metabolismo , Animais , Suínos
18.
Bioresour Technol ; 202: 25-32, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26700755

RESUMO

Mesophilic-hydrothermal (80-160 °C, 30 min)-thermophilic (M-H-T) digestion and control tests of mesophilic (M), thermophilic (T), hydrothermal-mesophilic (H-M), and mesophilic-thermophilic digestion (M-T) of green corn straw were conducted for a 20-day fermentation period. The results indicate that M-H-T is an efficient method to improve methane production. A maximum methane yield of 371.74 mL/g volatile solid was obtained by the M (3 days)-H (140 °C)-T (17 days) process, which was 20.44%, 16.55%, 31.44%, and 14.31% higher than the yields of the M, T, 140-M, and M-T processes. The enhanced methane production was attributed to (1) the improved hemicellulose degradation and lignin disorganization; (2) prevention of the degradation of soluble sugar, easily hydrolyzed hemicellulose and cellulose into furfural and methylfurfural; and (3) lack of formation of Maillard reaction products during initial hydrothermal treatment.


Assuntos
Biotecnologia/métodos , Temperatura Ambiente , Resíduos , Água/química , Zea mays/química , Hidrólise , Lignina/metabolismo , Metano/biossíntese , Fatores de Tempo
19.
Front Microbiol ; 6: 1337, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26648921

RESUMO

The microbial-mediated anaerobic digestion (AD) process represents an efficient biological process for the treatment of organic waste along with biogas harvest. Currently, the key factors structuring bacterial communities and the potential core and unique bacterial populations in manure anaerobic digesters are not completely elucidated yet. In this study, we collected sludge samples from 20 full-scale anaerobic digesters treating cattle or swine manure, and investigated the variations of bacterial community compositions using high-throughput 16S rRNA amplicon sequencing. Clustering and correlation analysis suggested that substrate type and free ammonia (FA) play key roles in determining the bacterial community structure. The COD: [Formula: see text] (C:N) ratio of substrate and FA were the most important available operational parameters correlating to the bacterial communities in cattle and swine manure digesters, respectively. The bacterial populations in all of the digesters were dominated by phylum Firmicutes, followed by Bacteroidetes, Proteobacteria and Chloroflexi. Increased FA content selected Firmicutes, suggesting that they probably play more important roles under high FA content. Syntrophic metabolism by Proteobacteria, Chloroflexi, Synergistetes and Planctomycetes are likely inhibited when FA content is high. Despite the different manure substrates, operational conditions and geographical locations of digesters, core bacterial communities were identified. The core communities were best characterized by phylum Firmicutes, wherein Clostridium predominated overwhelmingly. Substrate-unique and abundant communities may reflect the properties of manure substrate and operational conditions. These findings extend our current understanding of the bacterial assembly in full-scale manure anaerobic digesters.

20.
Bioresour Technol ; 189: 319-326, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25909453

RESUMO

In order to investigate the effects of feedstock ratio and organic loading rate (OLR) on the anaerobic mesophilic co-digestion of rice straw (RS) and cow manure (CM), batch tests (2.5L) were carried out at volatile solid (VS) ratios of 0:1, 1:2, 1:1, 2:1, and 1:0 (RS/CM), and continuous bench experiments (40 L) were carried out at OLRs of 3.0, 3.6, 4.2, 4.8, 6.0, 8.0, and 12.0 kg VS/(m(3) d) with optimal VS ratio. The optimal VS ratio was found to be 1:1. Stable and efficient co-digestion with average specific biogas production of 383.5L/kg VS and volumetric biogas production rate of 2.30 m(3)/(m(3) d) was obtained at an OLR of 6 kg VS/(m(3) d). Anaerobic co-digestion was severely inhibited by the accumulation of volatile fatty acids instead of ammonia when the OLR was 12 kg VS/(m(3) d). Further, significant foaming was observed at OLR ⩾ 8 kg VS/(m(3) d).


Assuntos
Esterco/análise , Compostos Orgânicos/farmacologia , Oryza/química , Eliminação de Resíduos/métodos , Temperatura Ambiente , Resíduos/análise , Álcalis/farmacologia , Anaerobiose/efeitos dos fármacos , Animais , Biocombustíveis/análise , Análise da Demanda Biológica de Oxigênio , Bovinos , Ácidos Graxos Voláteis/análise , Concentração de Íons de Hidrogênio , Metano/biossíntese , Volatilização
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