Effects of organic loading rate on reactor performance and archaeal community structure in mesophilic anaerobic digesters treating municipal sewage sludge

In this study, the organic loading rate (OLR) of a high-solids anaerobic digestion (HSAD) system was increased from 3.4 to 5.0 gVS L−1 day−1 and reactor stability, performance and microbial community structure were determined. Laboratory simulations (3.5 L) of the full-scale process (500 dry ton year−1) were conducted using continuously stirred-tank mesophilic reactors. OLRs of 3.4 gVS L−1day−1 (equal to the full-scale HSAD), 4.0, 4.5 and 5.0 gVS L−1day−1 were evaluated. Biochemical parameters and archaeal community dynamics were measured over 42 days of steady state operation. Results showed that increasing OLR increased the amount of organic matter conversion and resulted in higher organic matter removal and volumetric methane (CH4) production (VMP) rates. The highest volatile solids (VS) removal and VMP results of 54 ± 2% and 1.4 ± 0.1 L CH4 L−1day−1 were observed for 5.0 gVS L−1 day−1. The efficiency of reactor conversion of organic matter to CH4 was found to be similar in all the treatments with an average value of 0.57 ± 0.07 LCH4 gVS−1removed. 16S rRNA gene terminal restriction fragment polymorphism (T-RFLP) analyses revealed that archaeal TRFs remained stable during the experiment accounting for an average relative abundance (RA) of 81 ± 1%. Archaea consistent with multiple terminal restriction fragments (TRFs) included members of the Euryarchaeota and Crenarchaeota phyla, including acetoclastic and hydrogenotrophic groups. In conclusion, this laboratory-scale study suggests that performance and stability as well as the archaeal community structure in this HSAD system was unaffected by increasing the OLR by nearly 50% and that this increase resulted in a similar increase in the amount of CH4 gas generated.

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Anaerobic digester foaming in full-scale cylindrical digesters – Effects of organic loading rate, feed characteristics, and mixing

Bioresource Technology ◽

10.1016/j.biortech.2014.02.089 ◽

2014 ◽

Vol 159 ◽

pp. 182-192 ◽

Cited By ~ 21

Author(s):

Bhargavi Subramanian ◽

Krishna R. Pagilla

Keyword(s):

Loading Rate ◽

Anaerobic Digester ◽

Full Scale ◽

Organic Loading Rate ◽

Organic Loading

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Aerobic granular sludge in an SBR-system treating wastewater rich in particulate matter

Water Science & Technology ◽

10.2166/wst.2004.0799 ◽

2004 ◽

Vol 49 (11-12) ◽

pp. 41-46 ◽

Cited By ~ 66

Author(s):

N. Schwarzenbeck ◽

R. Erley ◽

P.A. Wilderer

Keyword(s):

Particle Size ◽

Organic Matter ◽

Primary Particle ◽

Loading Rate ◽

Granular Sludge ◽

Aerobic Granular Sludge ◽

Organic Loading Rate ◽

Organic Loading ◽

Particle Uptake ◽

Tracer Experiments

Aerobic granular sludge was successfully cultivated in a lab-scale SBR-system treating malting wastewater with a high content of particulate organic matter (0.9 gTSS/L). At an organic loading rate (CODtotal) of 3.4 kg/(m3·d) an average removal efficiency of 50% in CODtotal and 80% in CODdissolved was achieved. Fractionation of the COD by means of particle size showed that particles with a diameter less than 25–50 μm could be removed at 80% efficiency, whereas particles bigger than 50 μm were only removed at 40% efficiency. Tracer experiments revealed a dense sessile protozoa population covering the granules. The protozoa appeared to be responsible for primary particle uptake from the wastewater.

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Effect of organic loading rate on VFA production, organic matter removal and microbial activity of a two-stage thermophilic anaerobic membrane bioreactor

Bioresource Technology ◽

10.1016/j.biortech.2010.12.081 ◽

2011 ◽

Vol 102 (9) ◽

pp. 5353-5360 ◽

Cited By ~ 126

Author(s):

Kaushalya C. Wijekoon ◽

Chettiyappan Visvanathan ◽

Amila Abeynayaka

Keyword(s):

Organic Matter ◽

Microbial Activity ◽

Membrane Bioreactor ◽

Loading Rate ◽

Organic Loading Rate ◽

Organic Loading ◽

Two Stage ◽

Organic Matter Removal ◽

Anaerobic Membrane Bioreactor

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Effect of the Progressive Increase of Organic Loading Rate in an Anaerobic Sequencing Batch Reactor for Biodiesel Wastewater Treatment

Water ◽

10.3390/w14020223 ◽

2022 ◽

Vol 14 (2) ◽

pp. 223

Author(s):

Erlon Lopes Pereira ◽

Alisson Carraro Borges ◽

Greicelene Jesus da Silva

Keyword(s):

Organic Matter ◽

Wastewater Treatment ◽

Sequencing Batch Reactor ◽

Loading Rate ◽

Degradation Kinetics ◽

Batch Reactor ◽

Progressive Increase ◽

Organic Loading Rate ◽

Organic Loading ◽

Anaerobic Sequencing Batch Reactor

The wastewater from the biodiesel industry is an environmental problem, and from a sanitation resources perspective, the anaerobic sequencing batch reactor (ASBR) is an interesting alternative for wastewater treatment. A better understanding of ASBR operation behavior under the progressive increase of the organic loading rate (OLR) is crucial for upscaling. The objective of this study was to monitor an ASBR operating with an OLR ranging from 1.3 to 9.3 kgCOD m−3 d−1. The average chemical oxygen demand (COD) removal efficiencies of the ASBR were 52, 41, 47, and 11% for phases 1, 2, 3, and 4, respectively. The apparent kinetic coefficient, i.e., the rate of degradation of organic matter, was between 0.10 and 1.80 h−1, considering the kinetic model that considers the residual substrate concentration, which was the one that best fit the obtained data. The progressive increase in applied OLR modified the microbial biomass diversity, which in turn influenced the degradation kinetics of the organic matter. In addition, the values of the applied OLR of 5.1 kgCOD m−3 d−1 and a food to microorganism ratio (F/M) of 0.6 kgCOD kgVSS−1 d−1 were shown to be limiting values that promoted the overload of ASBR.

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Innovative Integrated Reactor System for Carbon, Sulfur and Nitrogen Removal Based on Biological Phase-Separation

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.518-523.2547 ◽

2012 ◽

Vol 518-523 ◽

pp. 2547-2552

Author(s):

Chun Shuang Liu ◽

Ai Jie Wang ◽

Chao Cheng Zhao

Keyword(s):

Organic Matter ◽

Phase Separation ◽

Loading Rate ◽

Maximum Level ◽

Operating Conditions ◽

Organic Loading Rate ◽

Organic Loading ◽

Operational Parameters ◽

Organic Matter Removal ◽

Metabolic Functions

An innovative biological wastewater treatment system for the removal of organic carbon, sulfur and nitrogen was developed based on biological phase-separation principle. This system consists of three reactors integrated together i.e. sulfate reduction and organic matter removal (SR-CR), autotrophic and heterotrophic denitrifying sulfide removal (A&H-DSR) and nitrification (AN) reactors. In this system, the operational parameters for successful bio-phase separation are sulfate and organic loading rate, hydraulic retention time (HRT), COD/SO42-ratio and pH for the SR-CR reactor, and sulfide and nitrate loading rate, HRT, pH, S2-/NO3-ratio and COD/NO3-for the A&H-DSR reactor. The results from a laboratory scale system demonstrated that for the SR-CR reactor, the optimal operating conditions were HRT≥24 h; sulfate and organic loading rate ≤7.5 kg SO42-/m3•d and ≤10 kgCOD/m3•d; COD/SO42-≥2; and pH ≥6.5. For A&H-DSR process, the optimal conditions are sulfide loading rate ≤6.0kg S2-/m3•d; nitrate loading rate ≤3.5 kg NO3-/m3•d; S2-/NO3-≥1; COD/NO3-≥1.25:1; and pH≥7.5. Under such conditions, high sulfate, ammonia and organic matter removal of 99%, 90% and 99% were achieved, respectively. In this case, the elemental sulfur (S0) reclamation efficiency reached 6.0 kg S0/m3•d, around 20 times higher than the maximum level as referred in the literatures. DGGE profiling indicated that the predominant functional organisms of Clostridiaceae sp., Desulfomicrobium sp., Methanosaeta sp. dominated in the SR-CR reactor, and Sulfurovum sp., Pseudomonas aeruginosa and Denitratisoma sp. in the A&H-DSR reactor. These species played essential role in metabolic functions in each bio-phase.

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Microbial community dynamics in replicate anaerobic digesters exposed sequentially to increasing organic loading rate, acidosis, and process recovery

Biotechnology for Biofuels ◽

10.1186/s13068-015-0309-9 ◽

2015 ◽

Vol 8 (1) ◽

Cited By ~ 93

Author(s):

Xavier Goux ◽

Magdalena Calusinska ◽

Sébastien Lemaigre ◽

Martyna Marynowska ◽

Michael Klocke ◽

...

Keyword(s):

Microbial Community ◽

Community Dynamics ◽

Loading Rate ◽

Organic Loading Rate ◽

Organic Loading ◽

Anaerobic Digesters ◽

Microbial Community Dynamics

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Start-up of full-scale anaerobic digesters treating municipal solid waste

Water Science & Technology ◽

10.2166/wst.2003.0264 ◽

2003 ◽

Vol 48 (4) ◽

pp. 249-252 ◽

Cited By ~ 1

Author(s):

T. Ohmura ◽

T. Sakai ◽

Y. Shindo ◽

K. Nakamura ◽

T. Ike ◽

...

Keyword(s):

Loading Rate ◽

Gas Production ◽

Full Scale ◽

Organic Loading Rate ◽

Organic Loading ◽

Methane Fermentation ◽

Start Up ◽

Direct Technique ◽

Short Period ◽

Sludge Recycling

Raising organic loading rate, and the behavior of dissolved CODcr (D-CODcr), VFA and specific methanogen activity, were investigated through a laboratory experiment for the start-up of a sludge recycling center. Moreover, application for MPN-PCR methods using a gene as a direct technique to measure the quantity of methanogen was attempted. It was recognized that specific methanogen activity depends on the quantity of methanogen, and that gas production does not reflect the condition of methane fermentation. The methane fermentation condition was checked through the specific methanogen activity and analysis of D-CODcr. The target organic loading rate was reached in the short period of about 30 days, and rapid start-up was successfully attained for a full-scale anaerobic digester.

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