scholarly journals Biochemical Conversion and Microbial Community in Response to Ternary pH Buffer System during Anaerobic Digestion of Swine Manure

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2991 ◽  
Author(s):  
Xiaoshan Meng ◽  
Yuxiu Zhang ◽  
Qianwen Sui ◽  
Junya Zhang ◽  
Rui Wang ◽  
...  
Keyword(s):  
Microbial Community ◽  
Anaerobic Digestion ◽  
Relative Abundance ◽  
Volatile Fatty Acids ◽  
Swine Manure ◽  
Total Solid ◽  
Buffer System ◽  
Biochemical Conversion ◽  
Ammonia Release ◽  
Ph Buffer

The ternary pH buffer system with ammonia-carbonates-volatile fatty acids (VFAs) is essential to anaerobes for bioenergy recovery via anaerobic digestion (AD). However, ammonia and VFAs are recognized as potential inhibitors that depress methanogenesis. In this study, biochemical conversion and the microbial community in batch AD at total solid (TS) from 4% to 14% were investigated to reveal their response to the ternary pH buffer system. The rapid ammonia release, probably promoted by Anaerosphaera and Eubacterium inferred from the concurrent peak of their relative abundance, triggered total ammonia (TAN) inhibition with the accumulation of VFAs in the start-up stage of high solid AD (HSAD, TS ≥ 8%). Along with evolution of the microbial community to resist high TAN and VFAs, methanogenesis recovered with improved degradation of VFAs and reduction of COD. When exposed to 3500 mg·N·L−1 TAN at 8% TS, aceticlastic Methanosarcina became dominant first and then together with hydrogenotrophic Methanoculleus, achieved the optimal biochemical conversion. While in HSAD at 11–14% TS, the main pathway of methanogenesis appeared to have shifted from the aceticlastic pathway to the hydrogenotrophic pathway, as inferred by changes in the relative abundance of methanogens, and this could have been induced by the increasing concentration of high free ammonia (FAN, ≥588 mg·N·L−1). Although the anaerobes had acclimatized to high TAN, the propionate-oxidizing bacteria and acetate-oxidizing bacteria might have again been inhibited by high FAN, frustrating the H2 supply for FAN-tolerant Methanoculleus and causing an 8.2–11.3% depression of COD reduction (mainly propionate residual).

Study of an enhanced dry anaerobic digestion of swine manure: Performance and microbial community property

2019 ◽  
Vol 282 ◽  
pp. 353-360 ◽  
Author(s):  
Yu-ying Hu ◽  
Jing Wu ◽  
Huai-zhi Li ◽  
Souhila Poncin ◽  
Kai-jun Wang ◽  
...  
Keyword(s):  
Microbial Community ◽  
Anaerobic Digestion ◽  
Swine Manure ◽  
Community Property ◽  
Dry Anaerobic Digestion

scholarly journals Comparison of functional microbial profile between mesophilic and thermophilic anaerobic digestion of vegetable waste

2020 ◽  
Author(s):  
Tianjie Ao ◽  
Zhijie Xie ◽  
Pan Zhou ◽  
Xiaofeng Liu ◽  
Liping Wan ◽  
...  
Keyword(s):  
Microbial Community ◽  
Anaerobic Digestion ◽  
Volatile Fatty Acids ◽  
Stable System ◽  
Microbial Consortia ◽  
Vegetable Waste ◽  
Microbial Profile ◽  
Hydrogenotrophic Methanogenesis ◽  
Highly Correlated ◽  
Stable Stage

Abstract Background With increasing accumulation of vegetable waste in China, the valorization of vegetable waste becomes an urgent concern. Based on the characteristics of high moisture content and biodegradable organic matter of vegetable waste, anaerobic digestion as an effective technique was selected to reuse this kind of agriculture waste. The anaerobic digestion performance is highly correlated with the functional microbial community. In this study, mesophilic and thermophilic digestions of vegetable waste were conducted, and dynamics of the microbial community were investigated. Results The mesophilic and thermophilic collapsed stages occurred at organic loading rates of 1.5 and 2.0 g volatile solid (VS)/(L·d), respectively, due to severe accumulation of volatile fatty acids. The mesophilic digestion exhibited a higher microbial diversity and richness than the thermophilic digestion. Syntrophic acetate-oxidizing coupled with hydrogenotrophic methanogenesis was the dominant pathway in the thermophilic stable system, and acetoclastic methanogenesis in the mesophilic stable system. The dominant acidogens, syntrophus, and methanogens were Candidatus_Cloacamonas, norank_f__Synergistaceae, Methanosaeta, and Methanosarcina in the mesophilic stable stage, and Anaerobaculum, Syntrophaceticus, Methanosarcina, and Methanothermobacter in thermophilic stable stage. Spirochaetae and Thermotogae phyla were the characteristic microorganisms in the mesophilic and thermophilic collapsed stages, respectively. Conclusions This study unveiled the distribution of the functional microbial consortia at the stable and collapsed periods of the anaerobic digestion of vegetable waste under mesophilic and thermophilic conditions to providing guidelines for the further research of anaerobic digestion of vegetable waste.

scholarly journals Anaerobic Digestion of Cigarette Butts: Microbial Community Analysis and Energy Production Estimation

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8290
Author(s):  
Okkyoung Choi ◽  
Sae Eun Hwang ◽  
Hyojung Park ◽  
Byoung-In Sang
Keyword(s):  
Microbial Community ◽  
Anaerobic Digestion ◽  
Methane Production ◽  
Energy Demand ◽  
Energy Production ◽  
Total Solid ◽  
Microbial Community Analysis ◽  
Cigarette Butts ◽  
Paper Filter ◽  
Bmp Test

Anaerobic digestion using cigarette butts, one of most littered items, was studied not only as a waste treatment, but also as an energy production method. Methane production from cigarette butts was measured through the biochemical methane potential (BMP) test and it was evaluated whether it is possible to produce electrical energy. Intact cigarettes or individual components (filter, paper, and leaf) were supplied as the sole carbon source (substrate) for the BMP test. The tendency of methane production indicated biodegradation in the order of paper, filter, and leaves; however, the filter of cigarettes was the substrate produced the highest amount of methane per total solid. The microbial community was also analyzed in each anaerobic digestion reactor, and substrate-specific microorganisms were identified, such as Proteiniphilum strain (filter) and Methanobacterium formicicum (paper). In intact cigarettes, the related microbial community became dominant over time in the order of paper, filter, and leaf. The conversion of cigarette butts to methane, a renewable energy source, can be proposed as a sustainable route for energy demand, for example, in a smoking room.

scholarly journals Effects of Lighter Dose of Oxytetracycline on the Accumulation and Degradation of Volatile Fatty Acids in the Process of Thermophilic Anaerobic Digestion of Swine Manure

2021 ◽  
Vol 13 (7) ◽  
pp. 4014
Author(s):  
Zijing Fan ◽  
Mei Zhang ◽  
Xiaxia Chen ◽  
Zhongda Hu ◽  
Qihang Shu ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Methane Production ◽  
Volatile Fatty Acids ◽  
Respiratory Infections ◽  
Swine Manure ◽  
Inhibitory Effect ◽  
Farm Animals ◽  
Original Form ◽  
Livestock Farming ◽  
Thermophilic Anaerobic Digestion

Oxytetracycline (OTC) is a commonly used antibiotic in livestock farming for controlling intestinal and respiratory infections in farm animals. However, the absorption of antibiotics by animals is limited, and most antibiotics are excreted in the original form with manure, which will have an impact on the environment. The removal of antibiotics from swine manure could generally be performed via anaerobic digestion (AD). In this study, the effect of oxytetracycline (OTC) at doses of 0.1, 0.5, and 1.0 mg/L on the thermophilic anaerobic digestion of swine manure (55 °C) in batch digesters was studied. The methane production, volatile fatty acid (VFA) levels, and dissolved organic matter (DOM) were determined and compared with the control (0 mg/L of OTC). The results indicate that (1) OTC at 0.1 mg/L had no inhibitory effect on methane production or on the accumulation of VFAs, while 0.5 mg/L and 1.0 mg/L inhibited methane production, with inhibition rates of 4.03% and 14.12% (p < 0.05), respectively; (2) the VFAs of each reactor peaked on the first day of the reaction, and as the OTC dose increased from 0 to 1.0 mg/L, the maximum VFA accumulation increased from 1346.94 mg/g to 2370 mg/g of volatile solids (VS); and (3) oxytetracycline (0.5 and 1.0 mg/L) could promote the temporary accumulation of propionic acid, which did, however, not result in significant VFA accumulation. Further, OTC at 1.0 mg/L can promote DOM production, and therefore, VFA accumulation.

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