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

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.

2008 ◽  
Vol 58 (10) ◽  
pp. 1895-1901 ◽  
Author(s):  
Bruce E. Rittmann ◽  
Hyung-sool Lee ◽  
Husen Zhang ◽  
Jared Alder ◽  
James E. Banaszak ◽  
...  

We tested at full-scale the innovative Focused Pulsed (FP) technology for pre-treating waste sludge in order to improve methane gas production and biosolids reduction in sludge digestion, but without incurring problems of odors, toxicity, and high costs for chemical or energy consumption. FP pre-treatment of a mixture of primary and secondary sludge increased the soluble COD by 160% and DOC 120% over the control. FP pre-treatment of 63% of the input waste sludge increased biogas production by over 40% and reduced biosolids requiring disposal by 30% when compared to the plant baseline. FP pre-treatment also correlated with a shift of the bacterial and archaeal communities. The most significant change was that the acetate-cleaving Methanosaeta became the dominant methanogen. Full FP pre-treatment should increase biogas production and biosolids removal by 60% and 40%, respectively. Full FP pre-treatment should generate energy benefits of at least 2.7 times and as high as 18 times the FP energy input, depending on heat recovery from FP treatment. For a plant treating 76,000 m3/d of wastewater (380 m3-sludge/d), FP treatment should generate an annual economic benefit of approximately $540,000 net of electricity and other operating and maintenance costs. This represents a payback period of three years or less.


1991 ◽  
Vol 23 (7-9) ◽  
pp. 1229-1237
Author(s):  
Chaio-Fuei Ouyang ◽  
Tain-Gen Chang

The treatment characteristics of municipal sludge were investigated by the anaerobic activated sludge digestion (AASD) system. This study used the suspended growth system and mesophilic temperature in the digestors and separators; the system achieves a more stable and improved process; such a process configuration offers the possibility of a substantial reduction in the total volume necessary for efficient stabilization. This study presents data indicating that the AASS system is feasible. In general, with an applied solids concentration of TS= 2%, the nonbiodegradable portion of the substrate concentration contained in the primary and secondary sludge was found to be 40.6% and 35.1% on the basis or TVS and COD, respectively. This study also provides evidence that the reactions at a recycling ratio of R=1 and R=3 are considerably more stable than those achieved in conventional or other recycling ratio digestors with a HRT of 9 days or longer. The gas production and bioactivity is also higher than that normally produced by the conventional single-stage digestion system. The experimental results also indicate that the dilution rate exceeds the maximum specific growth rate as the HRT is decreased from 9 days to 6 days. The significant saving in reactor volume and enhanced methane generation should offset the energy required for digested sludge recycling.


2018 ◽  
Vol 85 (5) ◽  
Author(s):  
Veronica R. Brand ◽  
Laurel D. Crosby ◽  
Craig S. Criddle

ABSTRACTMultiple clades within a microbial taxon often coexist within natural and engineered environments. Because closely related clades have similar metabolic potential, it is unclear how diversity is sustained and what factors drive niche differentiation. In this study, we retrieved three near-complete Competibacter lineage genomes from activated sludge metagenomes at a full-scale pure oxygen activated sludge wastewater treatment plant. The three genomes represent unique taxa within theCompetibacteraceae. A comparison of the genomes revealed differences in capacity for exopolysaccharide (EPS) biosynthesis, glucose fermentation to lactate, and motility. Using quantitative PCR (qPCR), we monitored these clades over a 2-year period. The clade possessing genes for motility and lacking genes for EPS biosynthesis (CPB_P15) was dominant during periods of suspended solids in the effluent. Further analysis of operational parameters indicate that the dominance of the CPB_P15 clade is associated with low-return activated sludge recycle rates and low wasting rates, conditions that maintain relatively high levels of biomass within the system.IMPORTANCEMembers of the Competibacter lineage are relevant in biotechnology as glycogen-accumulating organisms (GAOs). Here, we document the presence of threeCompetibacteraceaeclades in a full-scale activated sludge wastewater treatment plant and their linkage to specific operational conditions. We find evidence for niche differentiation among the three clades with temporal variability in clade dominance that correlates with operational changes at the treatment plant. Specifically, we observe episodic dominance of a likely motile clade during periods of elevated effluent turbidity, as well as episodic dominance of closely related nonmotile clades that likely enhance floc formation during periods of low effluent turbidity.


2013 ◽  
Vol 69 (6) ◽  
pp. 1227-1233 ◽  
Author(s):  
Vojtech Kouba ◽  
Michael Catrysse ◽  
Hana Stryjova ◽  
Ivana Jonatova ◽  
Eveline I. P. Volcke ◽  
...  

The application of nitrification–denitrification over nitrite (nitritation–denitritation) with municipal (i.e. diluted and cold (or low-temperature)) wastewater can substantially improve the energy balance of municipal wastewater treatment plants. For the accumulation of nitrite, it is crucial to inhibit nitrite-oxidizing bacteria (NOB) with simultaneous proliferation of ammonium-oxidizing bacteria (AOB). The present study describes the effect of the influent total ammonium nitrogen (TAN) concentration on AOB and NOB activity in two moving bed biofilm reactors operated as sequencing batch reactors (SBR) at 15 °C (SBR I) and 21 °C (SBR II). The reactors were fed with diluted reject water containing 600, 300, 150 and 75 mg TAN L−1. The only factor limiting NOB activity in these reactors was the high concentrations of free ammonia and/or free nitrous acid (FNA) during the SBR cycles. Nitrite accumulation was observed with influents containing 600, 300 and 150 mg TAN L−1 in SBR I and 600 and 300 in SBR II. Once nitrate production established in the reactors, the increase of influent TAN concentration up to the original 600 mg TAN L−1 did not limit NOB activity. This was due to the massive development of NOB clusters throughout the biofilm that were able to cope with faster formation of FNA. The results of the fluorescence in situ hybridization analysis preliminarily showed the stratification of bacteria in the biofilm.


2002 ◽  
Vol 46 (6-7) ◽  
pp. 347-354 ◽  
Author(s):  
E. Choi ◽  
Y. Eum

This study was conducted with an influent containing about 20% solids, obtainable from scraper type separation resulting in about 40 g/L TCOD and 5.5 g/L TKN, to find an optimum operating condition for nitrogen removal. Both laboratory scale reactors and a full scale treatment plant removed 80 to 90% nitrogen by biological means up to 35°C with 10% by ammonia stripping. The full scale plant however was operated at 35 to 45°C, and at 45°C, 30% nitrogen was removed by biological means, 50% by ammonia stripping, 14% by chemical coagulation and 6% by activated carbon adsorption, respectively. Struvite formation could not be observed at 30°C or higher. Nitrite nitrification and denitrification could save about 35% in tank volume and 50% in carbon requirements at 25°C, respectively. For a complete denitrification with a proper temperature, the influent TCOD/TKN ratio must exceed 6 with oxic/total reactor volume ratio of 0.5. The influent TCOD level or organic load should be lower so as not to increase the reactor temperature above 35°C and avoid nitrification inhibition. The estimated optimum nitrogen loading rates were 0.15 for summer and 0.23 kgTKN/m3/d for winter, respectively. With a cooling facility, the nitrogen loads could be increased to 0.35 kgTKN/m3/d equivalent to an organic loading rate of 2.5 kgCOD/m3/d.


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