scholarly journals Investigation on Recycling Dry Toilet Generated Blackwater by Anaerobic Digestion: From Energy Recovery to Sanitation

2021 ◽  
Vol 13 (8) ◽  
pp. 4090
Author(s):  
Siqi Zuo ◽  
Xiaoqin Zhou ◽  
Zifu Li ◽  
Xuemei Wang ◽  
Longbin Yu
Keyword(s):  
Acetic Acid ◽  
Anaerobic Digestion ◽  
Fermentation Broth ◽  
Ammonia Nitrogen ◽  
Ammonium Nitrogen ◽  
Adjustment Process ◽  
Biomethane Potential ◽  
Start Up ◽  
Acid Type ◽  
Total Ammonium

Anaerobic digestion (AD) has been widely adapted for blackwater treatment, however, the effect of water-conserving toilet generated blackwater on the AD process is still unknown. In this study, the anaerobic digestion process of dry toilet generated blackwater was investigated by means of a biomethane potential test. It was demonstrated that anaerobic digestion was inhibited and then adapted because of a high total ammonium nitrogen (TAN) level (3673.3 mg/L). The start-up period was 14.04 days and the biomethane potential of dry toilet blackwater was 402.36 mLCH4/gVS (55 days, 38 °C). Inhabitation and adaptation could be described as the increase of free ammonia nitrogen content and acetic acid concentration, followed by an enhancement of the relative abundance of acetic acid-type methanogens (from 33.53–61.52%). The main pathogen in dry toilet blackwater fermentation broth, Pseudomonas aeruginosa, kept multiplying in the first 8 days and then stabilized at a higher level than that of the beginning. This work showed the self-adjustment process and pathogen dynamics of dry toilet blackwater anaerobic digestion and highlights the significance of dry toilet blackwater characteristics when designing and maintaining anaerobic digestion sanitary treatment and reuse systems.

scholarly journals Bacterial Succession Pattern during the Fermentation Process in Whole-Plant Corn Silage Processed in Different Geographical Areas of Northern China

Processes ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 900
Author(s):  
Chao Wang ◽  
Hongyan Han ◽  
Lin Sun ◽  
Na Na ◽  
Haiwen Xu ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Bacterial Community ◽  
Inner Mongolia ◽  
Northern China ◽  
Ammonia Nitrogen ◽  
Corn Silage ◽  
Shanxi Province ◽  
Whole Plant ◽  
Bacterial Succession ◽  
Fermentation Quality

Whole-plant corn silage is a predominant forage for livestock that is processed in Heilongjiang province (Daqing city and Longjiang county), Inner Mongolia Autonomous Region (Helin county and Tumet Left Banner) and Shanxi province (Taigu and Shanyin counties) of North China; it was sampled at 0, 5, 14, 45 and 90 days after ensiling. Bacterial community and fermentation quality were analysed. During fermentation, the pH was reduced to below 4.0, lactic acid increased to above 73 g/kg DM (p < 0.05) and Lactobacillus dominated the bacterial community and had a reducing abundance after 14 days. In the final silages, butyric acid was not detected, and the contents of acetic acid and ammonia nitrogen were below 35 g/kg DM and 100 g/kg total nitrogen, respectively. Compared with silages from Heilongjiang and Inner Mongolia, silages from Shanxi contained less Lactobacillus and more Leuconostoc (p < 0.05), and had a separating bacterial community from 14 to 90 days. Lactobacillus was negatively correlated with pH in all the silages (p < 0.05), and positively correlated with lactic and acetic acid in silages from Heilongjiang and Inner Mongolia (p < 0.05). The results show that the final silages had satisfactory fermentation quality. During the ensilage process, silages from Heilongjiang and Inner Mongolia had similar bacterial-succession patterns; the activity of Lactobacillus formed and maintained good fermentation quality in whole-plant corn silage.

scholarly journals Microbiome of Seven Full-Scale Anaerobic Digestion Plants in South Korea: Effect of Feedstock and Operational Parameters

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 665
Author(s):  
Michal Sposob ◽  
Hee-Sung Moon ◽  
Dongjin Lee ◽  
Yeo-Myeong Yun
Keyword(s):  
Microbial Population ◽  
Ammonium Nitrogen ◽  
H2 Production ◽  
Full Scale ◽  
Organic Loading Rate ◽  
Operational Parameters ◽  
Sludge Digestion ◽  
Secondary Sludge ◽  
Potential Activity ◽  
Total Ammonium

In this study, the microbiomes linked with the operational parameters in seven mesophilic full-scale AD plants mainly treating food waste (four plants) and sewage sludge (three plants) were analyzed. The results obtained indicated lower diversity and evenness of the microbial population in sludge digestion (SD) plants compared to food digestion (FD) plants. Candidatus Accumulibacter dominated (up to 42.1%) in SD plants due to microbial immigration from fed secondary sludge (up to 89%). Its potential activity in SD plants was correlated to H2 production, which was related to the dominance of hydrogenotrophic methanogens (Methanococcus). In FD plants, a balance between the hydrogenotrophic and methylotrophic pathways was found, while Flavobacterium and Levilinea played an important role during acidogenesis. Levilinea also expressed sensitivity to ammonia in FD plants. The substantial differences in hydraulic retention time (HRT), organic loading rate (OLR), and total ammonium nitrogen (TAN) among the studied FD plants did not influence the archaeal methane production pathway. In addition, the bacterial genera responsible for acetate production through syntrophy and homoacetogenesis (Smithella, Treponema) were present in all the plants studied.

Assessment of the start-up process of anaerobic digestion utilizing swine manure: 13C fractionation of biogas and microbial dynamics

2019 ◽  
Vol 26 (13) ◽  
pp. 13275-13285 ◽  
Author(s):  
Zuopeng Lv ◽  
Jiazhuo Liang ◽  
Xin Chen ◽  
Zhongbing Chen ◽  
Jihong Jiang ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Swine Manure ◽  
Microbial Dynamics ◽  
Start Up

Sludge accumulation and methanogenic activity in an anaerobic lagoon

2000 ◽  
Vol 42 (10-11) ◽  
pp. 247-255 ◽  
Author(s):  
J. Paing ◽  
B. Picot ◽  
J. P. Sambuco ◽  
A. Rambaud
Keyword(s):  
Anaerobic Digestion ◽  
Methane Production ◽  
Anaerobic Degradation ◽  
Volatile Fatty Acids ◽  
Anaerobic Fermentation ◽  
Methanogenic Activity ◽  
Start Up ◽  
Anaerobic Lagoon ◽  
Methane Production Rate ◽  
Sludge Accumulation

Sludge accumulation and the characteristics of anaerobic digestion in sludge had been investigated in a primary anaerobic lagoon. Methanogenic potential of sludge was evaluated by an anaerobic digestion test which measured the methane production rate. Sludge was sampled at several points in the lagoon to determine spatial variations and with a monthly frequency from the start-up of the lagoon to observe the development of anaerobic degradation. Maximum amounts of sludge accumulated near the inlet. The mean methane production of sludge was 2.9 ml gVS–1 d–1. Sludge near the outlet presented a greater methanogenic activity and a lesser concentration of volatile fatty acids than near the inlet. The different stages of anaerobic degradation were spatially separated, acidogenesis near the inlet and methanogenesis near the outlet. This staged distribution seemed to increase efficiency of anaerobic fermentation compared with septic tanks. Methane release at the surface of the lagoon was estimated to be very heterogeneous with a mean of 25 l m–2 d–1. The development of performance and sludge characteristics showed the rapid beginning of methanogenesis, three months after the start-up of the anaerobic lagoon. Considering the volume of accumulated sludge, it could however be expected that methanogenic activity would further increase.

Control of sulfate reduction by molybdate in anaerobic digestion

1997 ◽  
Vol 36 (12) ◽  
pp. 143-150 ◽  
Author(s):  
Shuzo Tanaka ◽  
Young-Ho Lee
Keyword(s):  
Anaerobic Digestion ◽  
Sulfate Reduction ◽  
Methane Production ◽  
Phase 1 ◽  
Continuous Operation ◽  
Phase 2 ◽  
Sulfate Reducing ◽  
Start Up ◽  
Reducing Bacteria ◽  
Control Batch

Control of sulfate reduction by adding molybdate was investigated to enhance the methane production under batch and continuous operation in the anaerobic digestion of a sulfate-rich lysine wastewater. In phase 1 of the continuous operation, four anaerobic filters were fed with the lysine wastewater and then added with molybdate at 1,3,5 and 10 mM just after methane producing bacteria (MPB) were completely inhited by H2S produced by sulfate reducing bacteria (SRB). In phase 2, three anaerobic filters were operated with continuous or intermittent addition of 3 mM molybdate from the beginning of operation, including one with no molybdate as a control. Batch experiments revealed that the sulfate reduction was strongly inhibited and finally ceased by adding 3 mM or more of molybdate, resulting in great enhancement of the methane production. In phase 1 of the continuous experiments, all reactors showed the cessation of the methane production when the content of H2S reached 9–10 % in biogas, but the MPB activity was gradually recovered after initiating the molybdate addition at 3 or 5 mM. The 10 mM dosage of molybdate, however, had an inhibiting effect to MPB as well as SRB, resulting in the accumulation of acetate within the reactor. In phase 2, the control reactor continued to decrease the methane production, and a methane conversion rate was only 3 % in the control, while 35 and 10 % in continuously-added and intermittently-added reactors, respectively. Thus, it was confirmed that the MPB activity was greatly enhanced under control of the SRB activity by the continuous addition of molybdate. Comparing phase 2 with phase 1, addition from the start-up of the process is considered more effective than addition after the methane production dropped in the control of the sulfate reduction by molybdate.

scholarly journals Theoretical and Experimental Results on the Recovery of Potato Processing Residuals by Anaerobic Digestion

2019 ◽  
Vol 70 (7) ◽  
pp. 2524-2529 ◽  
Author(s):  
Andreea D. Dima ◽  
Carmen Mateescu ◽  
Oana C. Parvulescu ◽  
Eduard M. Lungulescu ◽  
Nicoleta O. Nicula
Keyword(s):  
Anaerobic Digestion ◽  
Gompertz Model ◽  
Economic Feasibility ◽  
Potato Processing ◽  
Biomethane Potential ◽  
Potato Waste ◽  
Cone Model ◽  
Treatment Technologies ◽  
Negative Environmental Impact ◽  
Modified Gompertz Model

Anaerobic digestion of organic matter with high moisture content has proven to be a suitable method for disposal of wet organic residuals with several advantages compared to other treatment technologies. This paper aimed at evaluating the theoretical and experimental biomethane potential of food processing residuals that are responsible for negative environmental impact, with exemplification for the potato processing waste. The biomethane potential is a useful parameter to assess the economic efficiency of anaerobic digestion processes as it can considerably influence the efficiency and the economic feasibility of the energy recovery technologies. Both experimental and theoretical biomethane potentials of potato waste in mesophilic anaerobic digestion as well as biodegradability of the substrate were estimated. Moreover, effects of microalgal extract addition on the digestion of potato waste were examined in an attempt to stimulate the anaerobic digestion. Cone model and a modified Gompertz model were used to predict the dynamics of biomethane production.

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