scholarly journals Microbial community analysis of a UASB reactor and application of an evolutionary algorithm to enhance wastewater treatment and biogas production

2015 ◽  
Author(s):  
◽  
Abimbola Motunrayo Enitan
Keyword(s):  
Microbial Community ◽  
Biogas Production ◽  
Methanogenic Archaea ◽  
Granular Sludge ◽  
Full Scale ◽  
Uasb Reactor ◽  
Brewery Wastewater ◽  
Effluent Quality ◽  
Ch4 Production ◽  
Species Specific

Anaerobic digestion, a proven and highly efficient biological process for treating industrial wastewater and biogas generation is an underutilized technology in South Africa. Some of the industries that have on-site anaerobic reactors tend to face problems in operating these reactors due to poor understanding of the process and implementation of the technology. This has resulted in high pollutant loads in their final effluents and low energy recovery. In this study, an on-site full–scale upflow anaerobic sludge blanket (UASB) reactor treating brewery wastewater was extensively monitored in order to evaluate the efficiency in terms of effluent quality, biogas production and microbial structure. Furthermore, developed and adopted kinetic models were used to optimize the performance of the full–scale UASB reactor using a combined Pareto differential evolution (CPMDE) algorithm. A preliminary analysis of the raw wastewater has shown that the wastewater produced from the brewery industry was high in organic matter with a total chemical oxygen demand (COD) between 1096.41 to 8926.08 mg/L. The average removal efficiency of COD from the UASB reactor after treatment was 79% with a methane (CH4) production of 60-69% at temperature ranges of 28-32˚C and hydraulic retention time (HRT) of 12 h within the optimal pH range for anaerobic bacteria (6.6 and 7.3) under various organic loading rates. However, the results also showed an increase in total suspended solids (TSS), nitrogen (N2), ammonia (NH3) and orthophosphate concentrations when comparing the influent to the effluent, which indicated the necessity for further optimization of the reactor condition in order to reduce these effluent parameters to acceptable standards and to increase CH4 production. In order to optimize the process, a thorough understanding of microbial interaction was essential. A combination of different molecular techniques viz., fluorescence in–situ hybridization (FISH), polymerase chain reaction (PCR) and quantitative real-time PCR (QPCR) were employed to understand the microbial community structure of the granular sludge samples using species specific primers and probes. The results revealed that the dominance of diverse groups of eubacteria belonging to phyla Proteobacteria, Firmicutes and Chloroflexi and an uncultured candidate division WS6 with four different orders of methanogenic Archaea viz., Methanomicrobiales, Methanococcales, Methanobacteriales and Methanosarcinales belonging to hydrogenotrophic and aceticlastic methanogens were within the reactor samples. Quantification of the 16S rDNA copies of eubacteria and methanogenic Archaea using species-specific primers further confirmed the spatial distribution of these microorganisms within the different compartments of the reactor where, the upper compartments were dominated by eubacteria and the lower compartments by methanogenic Archaea. The concentration of Archaea per nanogram of DNA was much higher (96.28%) than eubacteria (3.78%) in lower compartments, while, the eubacteria concentration increased to 98.34% in upper compartments with a decrease in Archaea quantity (1.66%). A modified kinetic methane generation model (MMGM) was developed on the basis of mass balance principles with respect to substrate (COD) degradation and the endogenous decay rate to predict CH4 production efficiency of the reactor. Furthermore, a Stover–Kincannon kinetic model was adopted with the aim of predicting the final effluent quality in terms of COD concentration and model coefficients were determined using the data collected from the full–scale reactor. Thereafter, a model-based multi-objective optimization was carried out using the CPMDE algorithm with three–objective functions namely; maximization of volumetric CH4 production rate; minimization of effluent substrate concentration and minimization of biomass washout, in order to increase the overall efficiency of the UASB reactor. Important decision variables and constraints related to the process were set for the optimization. A set of non-dominated solutions with high CH4 production rates of between 2.78 and 5.06 L CH4/g COD/day at low biomass washout concentrations were obtained at almost constant solution for the effluent COD concentration. A high COD removal efficiency (85-87%) at ~30-31˚C and 8-9 h HRT was obtained for the multi-objective optimization problem formulated. This study could significantly contribute towards optimization of a full–scale UASB reactor treating brewery wastewater for better effluent quality and biogas production. Knowledge on the activity and performance of microbial community present in the granular sludge taken from the full–scale UASB reactor would contribute significantly to future optimization strategies of the reactor. In addition, optimization using an evolutionary algorithm under different operational conditions would help to save both time and resources wasted in operating anaerobic bioreactors.

scholarly journals Microbiota of a Full-scale UASB Reactor Treating Brewery Wastewater Using Illumina MiSeq Sequencing

2019 ◽  
Vol 13 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Abimbola M. Enitan ◽  
Sheena Kumari ◽  
Feroz M. Swalaha ◽  
John O. Odiyo ◽  
Faizal Bux
Keyword(s):  
Community Structure ◽  
Microbial Community ◽  
Granular Sludge ◽  
Illumina Miseq ◽  
Full Scale ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Uasb Reactor ◽  
Brewery Wastewater ◽  
Scale Reactor

Background: The efficiency of biological wastewater treatment plant is determined by bacterial metabolism. There are data on the effect of operational parameters on microbial consortia present in laboratory scale reactor. However, knowledge on the full-scale reactor is still limited at present, hence the need to define the relations between the microbial structure and the performance of full-scale reactor. Objective: In this study, the microbial community structure in a full-scale UASB reactor treating brewery wastewater was assessed using metagenomics Next-Generation Sequencing technique. Method: Granular sludge samples were collected from the UASB reactor treating brewery wastewater and extracted genomic DNA was amplified using barcoded bacterial primer sets targeting V3-V4 region of the 16S rRNA genes on sequencing Illumina MiSeq platform. Results: The taxonomic analysis revealed the abundance of bacteria (~95%) with considerable Archaea community (~2%) in the granular sludge. After trimming, 18 bacterial phyla, 29 orders, 36 families and 44 genera were recovered from the 48,488 sequences reads of the 16S rRNA genes analysed, where the most abundant community belongs to Firmicutes, Bacteroidetes, Synergistetes and Proteobacteria phyla. Conclusion: For a sustainable bioenergy generation, understanding the mechanisms of anaerobic system in relation to microbial community is an important factor to increase the production of biogas production during wastewater treatment. To the best of our knowledge, this report is one of the studies that explored and described bacterial diversity and community structure of a full-scale UASB reactor treating brewery wastewater using high-throughput sequencing. This study provides insight into the dominant microbial community and their phylogenetic diversity in biogas producing reactor.

Anaerobic co-digestion of surplus yeast and wastewater to increase energy recovery in breweries

2010 ◽  
Vol 61 (5) ◽  
pp. 1129-1135 ◽  
Author(s):  
K. Neira ◽  
D. Jeison
Keyword(s):  
Biogas Production ◽  
Granular Sludge ◽  
Uasb Reactor ◽  
Brewery Wastewater ◽  
Negative Effects ◽  
Biogas Yield ◽  
Batch Tests ◽  
Treatment Step ◽  
Long Term Studies

Surplus yeast is a residue produced during brewery process, which presents high contents of organic matter. Biogas production from yeast could significantly contribute to bioenergy production in breweries, via biogas generation. Co-digestion of surplus yeast and brewery wastewater in a single treatment step would simplify the technical and economical requirements for the transformation of both residues into biogas. The feasibility of such co-digestion process was studied by means of batch tests and a lab-scale UASB reactor operation. The effect of applying three pre-treatments (thermal, chemical and mechanical) to the surplus yeast was also studied. Results showed that co-digestion of yeast and brewery wastewater is feasible, since no negative effects of the joint digestion were observed. Pre-treatments tested in this research produced no significant improvements on biogas yield or digestion rates. Even though no negative effects were observed when digesting wastewater and yeast in a UASB reactor after 70 days, long-term studies would be needed in order to detect potential negative effects over granular sludge development, sometimes observed during the treatment of some wastewaters containing suspended solids.

scholarly journals Microbial Diversity Dynamics in a Methanogenic-Sulfidogenic UASB Reactor

2021 ◽  
Vol 18 (3) ◽  
pp. 1305
Author(s):  
E. Fernández-Palacios ◽  
Xudong Zhou ◽  
Mabel Mora ◽  
David Gabriel
Keyword(s):  
Paper Industry ◽  
Chemical Species ◽  
Methanogenic Archaea ◽  
Granular Sludge ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Rrna Gene ◽  
Sulfate Reducing ◽  
Long Run

In this study, the long-term performance and microbial dynamics of an Upflow Anaerobic Sludge Blanket (UASB) reactor targeting sulfate reduction in a SOx emissions treatment system were assessed using crude glycerol as organic carbon source and electron donor under constant S and C loading rates. The reactor was inoculated with granular sludge obtained from a pulp and paper industry and fed at a constant inlet sulfate concentration of 250 mg S-SO42−L−1 and a constant C/S ratio of 1.5 ± 0.3 g Cg−1 S for over 500 days. Apart from the regular analysis of chemical species, Illumina analyses of the 16S rRNA gene were used to study the dynamics of the bacterial community along with the whole operation. The reactor was sampled along the operation to monitor its diversity and the changes in targeted species to gain insight into the performance of the sulfidogenic UASB. Moreover, studies on the stratification of the sludge bed were performed by sampling at different reactor heights. Shifts in the UASB performance correlated well with the main shifts in microbial communities of interest. A progressive loss of the methanogenic capacity towards a fully sulfidogenic UASB was explained by a progressive wash-out of methanogenic Archaea, which were outcompeted by sulfate-reducing bacteria. Desulfovibrio was found as the main sulfate-reducing genus in the reactor along time. A progressive reduction in the sulfidogenic capacity of the UASB was found in the long run due to the accumulation of a slime-like substance in the UASB.

Characterization of microbial community in granular sludge treating brewery wastewater

2002 ◽  
Vol 36 (7) ◽  
pp. 1767-1775 ◽  
Author(s):  
Wen-Tso Liu ◽  
On-Chim Chan ◽  
Herbert H.P Fang
Keyword(s):  
Microbial Community ◽  
Granular Sludge ◽  
Brewery Wastewater

Microbial community evaluation of anaerobic granular sludge from a hybrid reactor treating pentachlorophenol by using fluorescence in situ hybridization

2003 ◽  
Vol 48 (6) ◽  
pp. 65-73 ◽  
Author(s):  
M.A.P. Montenegro ◽  
J.C. Araujo ◽  
R.F. Vazoller
Keyword(s):  
In Situ Hybridization ◽  
Microbial Community ◽  
Methanogenic Archaea ◽  
Granular Sludge ◽  
Hybrid Reactor ◽  
Anaerobic Granular Sludge ◽  
Bacterial Cells ◽  
Before And After ◽  
Community Evaluation

We used in situ hybridization with fluorescently labeled rRNA-targeted oligonucleotide probes concurrently with microscopic examinations and methane measurements to characterize the microbial community of an anaerobic hybrid reactor treating pentachlorophenol (PCP) with a mixture of fatty acids (propionic, butyric, acetic and lactic) and methanol. Archaeal cells detected with probe ARC915 prevailed in anaerobic granular sludge without and with the addition of PCP in a range of 2.0 to 21.0 mg/L to the reactor. This group accounted for 81 and 90% of the DAPI-stained cells before and after the addition of 21 mg/L of PCP, respectively. In these conditions, cells detected with the Methanosarcinales specific probe (MSMX860) were the only methanogenic Archaea found and accounted for 59 to 87.6% of the DAPI-stained cells. No cells were detected by the Methanomicrobiales (MG1200), Methanobacteriaceae (MB1174) and Methanococcaceae (MC1109) specific probes. Bacterial cells detected with probe EUB338 were found in very low numbers, which ranged from 5.7 to 1.0% of the DAPI-stained cells. This finding agrees with the scanning electron microscope examinations, in which cells morphologically resembling Methanosaeta and Methanosarcina were predominantly observed in the granular sludge. Results contributed to the investigation of the importance of the methanogens during PCP degradation.

Kinetic Modelling and Characterization of Microbial Community Present in a Full-Scale UASB Reactor Treating Brewery Effluent

2013 ◽  
Vol 67 (2) ◽  
pp. 358-368 ◽  
Author(s):  
Abimbola M. Enitan ◽  
Sheena Kumari ◽  
Feroz M. Swalaha ◽  
J. Adeyemo ◽  
Nishani Ramdhani ◽  
...  
Keyword(s):  
Microbial Community ◽  
Kinetic Modelling ◽  
Full Scale ◽  
Uasb Reactor ◽  
Brewery Effluent

Impact of aluminum chloride on process performance and microbial community structure of granular sludge in an upflow anaerobic sludge blanket reactor for natural rubber processing wastewater treatment

2016 ◽  
Vol 74 (2) ◽  
pp. 500-507 ◽  
Author(s):  
Nguyen Thi Thanh ◽  
Takahiro Watari ◽  
Tran Phuong Thao ◽  
Masashi Hatamoto ◽  
Daisuke Tanikawa ◽  
...  
Keyword(s):  
Community Structure ◽  
Microbial Community ◽  
Natural Rubber ◽  
Microbial Community Structure ◽  
Aluminum Chloride ◽  
Granular Sludge ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Anaerobic Sludge Blanket

In this study, granular sludge formation was carried out using an aluminum chloride supplement in an upflow anaerobic sludge blanket (UASB) reactor treating natural rubber processing wastewater. Results show that during the first 75 days after the start-up of the UASB reactor with an organic loading rate (OLR) of 2.65 kg-COD·m−3·day−1, it performed stably with a removal of 90% of the total chemical oxygen demand (COD) and sludge still remained in small dispersed flocs. However, after aluminum chloride was added at a concentration of 300 mg·L−1 and the OLR range was increased up to 5.32 kg-COD·m−3·day−1, the total COD removal efficiency rose to 96.5 ± 2.6%, with a methane recovery rate of 84.9 ± 13.4%, and the flocs began to form granules. Massively parallel 16S rRNA gene sequencing of the sludge retained in the UASB reactor showed that total sequence reads of Methanosaeta sp. and Methanosarcina sp., reported to be the key organisms for granulation, increased after 311 days of operation. This indicates that the microbial community structure of the retained sludge in the UASB reactor at the end of the experiment gave a good account of itself in not only COD removal, but also granule formation.

scholarly journals Changes in the Substrate Source Reveal Novel Interactions in the Sediment-Derived Methanogenic Microbial Community

2019 ◽  
Vol 20 (18) ◽  
pp. 4415 ◽  
Author(s):  
Anna Szafranek-Nakonieczna ◽  
Anna Pytlak ◽  
Jarosław Grządziel ◽  
Adam Kubaczyński ◽  
Artur Banach ◽  
...  
Keyword(s):  
Microbial Community ◽  
Production Rate ◽  
Yeast Extract ◽  
Methane Production ◽  
Biogas Production ◽  
Carbon Sources ◽  
Methanogenic Archaea ◽  
Methane Formation ◽  
Natural Environments ◽  
Methane Production Rate

Methanogenesis occurs in many natural environments and is used in biotechnology for biogas production. The efficiency of methane production depends on the microbiome structure that determines interspecies electron transfer. In this research, the microbial community retrieved from mining subsidence reservoir sediment was used to establish enrichment cultures on media containing different carbon sources (tryptone, yeast extract, acetate, CO2/H2). The microbiome composition and methane production rate of the cultures were screened as a function of the substrate and transition stage. The relationships between the microorganisms involved in methane formation were the major focus of this study. Methanogenic consortia were identified by next generation sequencing (NGS) and functional genes connected with organic matter transformation were predicted using the PICRUSt approach and annotated in the KEGG. The methane production rate (exceeding 12.8 mg CH4 L−1 d−1) was highest in the culture grown with tryptone, yeast extract, and CO2/H2. The analysis of communities that developed on various carbon sources casts new light on the ecophysiology of the recently described bacterial phylum Caldiserica and methanogenic Archaea representing the genera Methanomassiliicoccus and Methanothrix. Furthermore, it is hypothesized that representatives of Caldiserica may support hydrogenotrophic methanogenesis.

scholarly journals Effect of an Increased Particulate COD Load on the Aerobic Granular Sludge Process: A Full Scale Study

Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1472
Author(s):  
Sara Toja Ortega ◽  
Mario Pronk ◽  
Merle K. de Kreuk
Keyword(s):  
Microbial Community ◽  
Nutrient Removal ◽  
Microbial Community Composition ◽  
Treatment Plant ◽  
Granular Sludge ◽  
Full Scale ◽  
Test Period ◽  
Normal Operation ◽  
Aerobic Granular Sludge ◽  
Hydrolytic Activities

High concentrations of particulate COD (pCOD) in the influent of aerobic granular sludge (AGS) systems are often associated to small granule diameter and a large fraction of flocculent sludge. At high particulate concentrations even granule stability and process performance might be compromised. However, pilot- or full-scale studies focusing on the effect of real wastewater particulates on AGS are scarce. This study describes a 3-month period of increased particulate loading at a municipal AGS wastewater treatment plant. The pCOD concentration of the influent increased from 0.5 g COD/L to 1.3 g COD/L, by adding an untreated slaughterhouse wastewater source to the influent. Sludge concentration, waste sludge production and COD and nutrient removal performance were monitored. Furthermore, to investigate how the sludge acclimatises to a higher influent particulate content, lipase and protease hydrolytic activities were studied, as well as the microbial community composition of the sludge. The composition of the granule bed and nutrient removal efficiency did not change considerably by the increased pCOD. Interestingly, the biomass-specific hydrolytic activities of the sludge did not increase during the test period either. However, already during normal operation the aerobic granules and flocs exhibited a hydrolytic potential that exceeded the influent concentrations of proteins and lipids. Microbial community analysis also revealed a high proportion of putative hydrolysing and fermenting organisms in the sludge, both during normal operation and during the test period. The results of this study highlight the robustness of the full-scale AGS process, which can bear a substantial increase in the influent pCOD concentration during an extended period.

Sludge deterioration in a full scale UASB reactor after a pH drop working under low loading conditions

2008 ◽  
Vol 57 (5) ◽  
pp. 797-802 ◽  
Author(s):  
L. Borzacconi ◽  
I. López ◽  
M. Passeggi ◽  
C. Etchebehere ◽  
R. Barcia
Keyword(s):  
Removal Efficiency ◽  
Biogas Production ◽  
Industrial Process ◽  
Full Scale ◽  
Cod Removal ◽  
Normal Operation ◽  
Uasb Reactor ◽  
Organic Load ◽  
Reactor Performance ◽  
Cod Removal Efficiency

A full scale UASB reactor treating the effluent of a malting plant was operated during nearly two years. During 37 weeks of operation the reactor worked with a COD removal efficiency of 80% and a biogas production of nearly 300 m3/d with a methane content of 77%. After the start up and during these months of operation the volumetric organic load was 4 kgCOD/m3.d and the specific organic load was between 0.2–0.4 kgCOD/kgVSS.d. The sludge SMA in this period was around 0.25 kgCOD/kg VSS.d. On week 37 as a result of a problem at the industrial process the pH in the reactor dropped to a value of 4.8. After pH recovering, the reactor worked with fluctuating COD values in the exit and showed a downward trend in the COD removal efficiency. On week 81 the presence of filaments in the granules was detected. High proportion of Chloroflexi filaments were detected by FISH in the sludge. Changes in the microbial population caused by the low pH probably destabilize the reactor performance. The presence of filamentous granules in the sludge and its further growing could be encouraged by the pH drop and the low specific organic load applied to the reactor. The low specific organic load was a consequence of the high VSS content in the UASB reactor, due to the lack of purges. The length of the filaments attached to the granules grew throughout time. In order to eliminate the sludge with poor settlement properties a recycle was applied to the reactor. As a consequence, low amount of granular sludge stayed in the reactor. At the end, COD concentration in the influent reached higher values than in normal operation; at the same time a complete sludge wash out occurred. On the other hand, using the same sludge (after the recycle implementation) in a bench scale reactor the good properties of the sludge were completely recovered.

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