41 results on '"Syutsubo, K."'
Search Results
2. Treatment of natural rubber processing wastewater using a combination system of a two-stage up-flow anaerobic sludge blanket and down-flow hanging sponge system
- Author
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Tanikawa, D., primary, Syutsubo, K., primary, Hatamoto, M., primary, Fukuda, M., primary, Takahashi, M., primary, Choeisai, P. K., primary, and Yamaguchi, T., primary
- Published
- 2016
- Full Text
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3. Downflow sponge biofilm reactors for polluted raw water treatment: Performance optimisation, kinetics, and microbial community.
- Author
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Loi JX, Syutsubo K, Rabuni MF, Takemura Y, Aoki M, and Chua ASM
- Subjects
- Ammonium Compounds metabolism, Water Purification methods, Kinetics, Water Pollutants, Chemical metabolism, Water Pollutants, Chemical analysis, Waste Disposal, Fluid methods, Microbiota, Nitrites metabolism, Bacteria metabolism, Bacteria genetics, RNA, Ribosomal, 16S genetics, Nitrates metabolism, Biofilms, Bioreactors microbiology, Nitrification
- Abstract
Water outages caused by elevated ammonium (NH
4 + -N) levels are a prevalent problem faced by conventional raw water treatment plants in developing countries. A treatment solution requires a short hydraulic retention time (HRT) to overcome nitrification rate limitation in oligotrophic conditions. In this study, the performance of polluted raw water treatment using a green downflow sponge biofilm (DSB) technology was evaluated. We operated two DSB reactors, DSB-1 and DSB-2 under different NH4 + -N concentration ranges (DSB-1: 3.2-5.0 mg L-1 ; DSB-2: 1.7-2.6 mg L-1 ) over 360 days and monitored their performance under short HRT (60 min, 30 min, 20 min, and 15 min). The experimental results revealed vertical segregation of organic removal in the upper reactor depths and nitrification in the lower depths. Under the shortest HRT of 15 min, both DSB reactors achieved stable NH4 + -N and chemical oxygen demand removal (≥95%) and produced minimal effluent nitrite (NO2 - -N). DSB system could facilitate complete NH4 + -N oxidation to nitrate (NO3 - -N) without external aeration energy requirement. The 16S rRNA sequencing data revealed that nitrifying bacteria Nitrosomonas and Nitrospira in the reactor were stratified. Putative comammox bacteria with high ammonia affinity was successfully enriched in DSB-2 operating at a lower NH4 + -N loading rate, which is advantageous in oligotrophic treatment. This study suggests that a high hydraulic rate DSB system with efficient ammonia removal could incorporate ammonia treatment capability into polluted raw water treatment process and ensure safe water supply in many developing countries., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)- Published
- 2024
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4. Escherichia coli removal in down-flow hanging sponge reactors: insights from laboratory reactor studies.
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Tomioka N, Tran P T, Aoki M, Takemura Y, and Syutsubo K
- Subjects
- Waste Disposal, Fluid methods, Waste Disposal, Fluid instrumentation, Wastewater microbiology, Water Purification methods, Water Purification instrumentation, Escherichia coli, Bioreactors microbiology
- Abstract
Down-flow hanging sponge (DHS) reactors, employed in domestic wastewater treatment, have demonstrated efficacy in eliminating Escherichia coli and other potentially pathogenic bacteria. The aim of this study was to elucidate the mechanism of removal of E. coli by employing a cube-shaped polyurethane sponge carrier within a compact hanging reactor. An E. coli removal experiment was conducted on this prepared sponge. Escherichia. coli level was found to decrease by more than 2 logs after passing through five nutrient-restricted DHS sponges. Conversely, a newly introduced sponge did not exhibit a comparable reduction in E. coli level. Furthermore, under conditions of optimal nutritional status, the reduction in E. coli level was limited to 0.5 logs, underscoring the crucial role of nutrient restriction in achieving effective elimination. Analysis of the sponge-associated bacterial community revealed the presence of a type VI secretion system (T6SS), a competitive mechanism observed in bacteria. This finding suggests that T6SS might play a pivotal role in contributing to the observed decline in E. coli level.
- Published
- 2024
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5. A quantitative sequencing method using synthetic internal standards including functional and phylogenetic marker genes.
- Author
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Koike K, Honda R, Aoki M, Yamamoto-Ikemoto R, Syutsubo K, and Matsuura N
- Subjects
- Phylogeny, RNA, Ribosomal, 16S genetics, Sequence Analysis, DNA, Genes, Bacterial, DNA
- Abstract
The method of spiking synthetic internal standard genes (ISGs) to samples for amplicon sequencing, generating sequences and converting absolute gene numbers from read counts has been used only for phylogenetic markers and has not been applied to functional markers. In this study, we developed ISGs, including gene sequences of the 16S rRNA, pmoA, encoding a subunit of particulate methane monooxygenase and amoA, encoding a subunit of ammonia monooxygenase. We added ISGs to the samples, amplified the target genes and performed amplicon sequencing. For the mock community, the copy numbers converted from read counts using ISGs were equivalent to those obtained by the quantitative real-time polymerase chain reaction (4.0 × 10
4 versus 4.1 × 104 and 3.0 × 103 versus 4.0 × 103 copies μL-DNA-1 for 16S rRNA and pmoA genes, respectively), but we also identified underestimation, possibly due to primer coverage (7.8 × 102 versus 3.7 × 103 μL-DNA-1 for amoA gene). We then applied this method to environmental samples and analysed phylogeny, functional diversity and absolute quantities. One Methylocystis population was most abundant in the sludge samples [16S rRNA gene (3.8 × 109 copies g-1 ) and the pmoA gene (2.3 × 109 copies g-1 )] and were potentially interrelated. This study demonstrates that ISG spiking is useful for evaluating sequencing data processing and quantifying functional markers., (© 2023 The Authors. Environmental Microbiology Reports published by Applied Microbiology International and John Wiley & Sons Ltd.)- Published
- 2023
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6. Quantitative detection and reduction of potentially pathogenic bacterial groups of Aeromonas, Arcobacter, Klebsiella pneumoniae species complex, and Mycobacterium in wastewater treatment facilities.
- Author
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Aoki M, Takemura Y, Kawakami S, Yoochatchaval W, Tran P T, Tomioka N, Ebie Y, and Syutsubo K
- Subjects
- Wastewater, Klebsiella pneumoniae genetics, Klebsiella genetics, RNA, Ribosomal, 16S genetics, Escherichia coli genetics, Arcobacter genetics, Aeromonas genetics, Water Purification, Mycobacterium genetics
- Abstract
Water quality parameters influence the abundance of pathogenic bacteria. The genera Aeromonas, Arcobacter, Klebsiella, and Mycobacterium are among the representative pathogenic bacteria identified in wastewater. However, information on the correlations between water quality and the abundance of these bacteria, as well as their reduction rate in existing wastewater treatment facilities (WTFs), is lacking. Hence, this study aimed to determine the abundance and reduction rates of these bacterial groups in WTFs. Sixty-eight samples (34 influent and 34 non-disinfected, treated, effluent samples) were collected from nine WTFs in Japan and Thailand. 16S rRNA gene amplicon sequencing analysis revealed the presence of Aeromonas, Arcobacter, and Mycobacterium in all influent wastewater and treated effluent samples. Quantitative real-time polymerase chain reaction (qPCR) was used to quantify the abundance of Aeromonas, Arcobacter, Klebsiella pneumoniae species complex (KpSC), and Mycobacterium. The geometric mean abundances of Aeromonas, Arcobacter, KpSC, and Mycobacterium in the influent wastewater were 1.2 × 104-2.4 × 105, 1.0 × 105-4.5 × 106, 3.6 × 102-4.3 × 104, and 6.9 × 103-5.5 × 104 cells mL-1, respectively, and their average log reduction values were 0.77-2.57, 1.00-3.06, 1.35-3.11, and -0.67-1.57, respectively. Spearman's rank correlation coefficients indicated significant positive or negative correlations between the abundances of the potentially pathogenic bacterial groups and Escherichia coli as well as water quality parameters, namely, chemical/biochemical oxygen demand, total nitrogen, nitrate-nitrogen, nitrite-nitrogen, ammonium-nitrogen, suspended solids, volatile suspended solids, and oxidation-reduction potential. This study provides valuable information on the development and appropriate management of WTFs to produce safe, hygienic water., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Aoki et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)
- Published
- 2023
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7. Enhanced sulfide removal by gas stripping in a novel reactor for anaerobic wastewater treatment.
- Author
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Onodera T, Takemura Y, Aoki M, and Syutsubo K
- Subjects
- Anaerobiosis, Biofuels, Waste Disposal, Fluid, Bioreactors, Sulfides, Gases, Wastewater, Water Purification
- Abstract
Removal of sulfide by gas stripping using biogas produced in an internal phase-separated reactor (IPSR) was evaluated during anaerobic treatment. The IPSR consisted of upper and lower segments with a gas-liquid partitioning (GLP) valve between the sections. Wastewater was fed to the upper segment in the first stage and then to the lower segment in the second stage. The GLP valve separated the liquid phase from the gaseous phase and supplied biogas from the lower segment to the upper segment. The IPSR and a control reactor were fed with synthetic wastewater and operated in parallel under an organic loading rate of 12 kg COD/(m
3 day) at 35 °C. The sulfide concentration increased to 400-600 mg S/L, which is above the previously reported 50% inhibition level for methanogenic activity. The IPSR showed higher H2 S removal performance than the control reactor and removed approximately twice the H2 S as the control reactor at 400 mg S/L, indicating that it can be used for the stable treatment of wastewater containing high concentrations of sulfide.- Published
- 2023
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8. Isolation and physiological properties of methanogenic archaea that degrade tetramethylammonium hydroxide.
- Author
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Iguchi A, Takemura Y, Danshita T, Kurihara T, Aoki M, Hori S, Shigematsu T, and Syutsubo K
- Subjects
- Wastewater, Sewage chemistry, In Situ Hybridization, Fluorescence, RNA, Ribosomal, 16S genetics, RNA, Ribosomal, 16S metabolism, Bioreactors, Methanosarcinaceae genetics, Anaerobiosis, Waste Disposal, Fluid methods, Archaea genetics, Archaea metabolism, Euryarchaeota metabolism
- Abstract
Tetramethylammonium hydroxide (TMAH) is a known toxic chemical used in the photolithography process of semiconductor photoelectronic processes. Significant amounts of wastewater containing TMAH are discharged from electronic industries. It is therefore attractive to apply anaerobic treatment to industrial wastewater containing TMAH. In this study, a novel TMAH-degrading methanogenic archaeon was isolated from the granular sludge of a psychrophilic upflow anaerobic sludge blanket (UASB) reactor treating synthetic wastewater containing TMAH. Although the isolate (strain NY-STAYD) was phylogenetically related to Methanomethylovorans uponensis, it was the only isolated Methanomethylovorans strain capable of TMAH degradation. Strain NY-STAYD was capable of degrading methylamine compounds, similar to the previously isolated Methanomethylovorans spp. While the strain was able to grow at temperatures ranging from 15 to 37°C, the cell yield was higher at lower temperatures. The distribution of archaeal cells affiliated with the genus Methanomethylovorans in the original granular sludge was investigated by fluorescence in situ hybridization (FISH) using specific oligonucleotide probe targeting 16S rRNA. The results demonstrated that the TMAH-degrading cells associated with the genus Methanomethylovorans were not intermingled with other microorganisms but rather isolated on the granule's surface as a lone dominant archaeon. KEY POINTS: • A TMAH-degrading methanogenic Methanomethylovorans strain was isolated • This strain was the only known Methanomethylovorans isolate that can degrade TMAH • The highest cell yield of the isolate was obtained at psychrophilic conditions., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)
- Published
- 2023
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9. Effects of sulfate concentration on anaerobic treatment of wastewater containing monoethanolamine using an up-flow anaerobic sludge blanket reactor.
- Author
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Takemura Y, Aoki M, Danshita T, Iguchi A, Ikeda S, Miyaoka Y, Sumino H, and Syutsubo K
- Subjects
- Anaerobiosis, Bioreactors, Ethanolamine, Hydrogen, Methane metabolism, Propionates, Sucrose, Sulfates, Waste Disposal, Fluid, Sewage, Wastewater
- Abstract
Monoethanolamine (MEA), a toxic organic chemical, is widely used in industries and is found in their wastewater. Anaerobic MEA degradation is an appropriate strategy to reduce energy and cost for treatment. Industry wastewaters also contain sulfate, but information on the effects of sulfate on MEA degradation is limited. Here, an up-flow anaerobic sludge blanket (UASB) for MEA-containing wastewater treatment was operated under psychrophilic conditions (18-20 ºC) to investigate the effects of sulfate on the microbial characteristics of the retained sludge. To acclimatize the sludge, the proportion of MEA in the influent (containing sucrose, acetate, and propionate) was increased from 15% to 100% of total COD (1500 mg L
-1 ); sulfate was then added to the influent. The COD removal efficiency remained above 95% despite the increase in MEA and sulfate. However, granular sludge disintegration was observed when sulfate was increased from 20 to 330 mg L-1 . Batch tests revealed that propionate and acetate were produced as the metabolites of MEA degradation. In response to sulfate acclimation, methane-producing activities for propionate and hydrogen declined, while sulfate-reducing activities for MEA, propionate, and hydrogen increased. Accordingly, acclimation and changes in dominant microbial groups promoted the acetogenic reaction of propionate by sulfate reduction., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Kazuaki Syutsubo reports financial support was provided by Japan Society for the Promotion of Science., (Copyright © 2022 Elsevier B.V. All rights reserved.)- Published
- 2022
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10. Metagenome-Assembled Genome Sequence of Marine Rhizobiaceae sp. Strain MnEN-MB40S, Obtained from Manganese-Oxidizing Enrichment Culture.
- Author
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Aoki M, Nakahara N, Kusube M, and Syutsubo K
- Abstract
Here, we report a new metagenome-assembled genome (MAG) from a marine Rhizobiaceae species. The MnEN-MB40S genome was assembled from a manganese-oxidizing enrichment culture metagenome. A 4.1-Mb MAG comprising 26 contigs, with a GC content of 60.0%, was obtained. This MAG contributes to the genomic information regarding the family Rhizobiaceae .
- Published
- 2022
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11. Manganese oxidation and prokaryotic community analysis in a polycaprolactone-packed aerated biofilm reactor operated under seawater conditions.
- Author
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Aoki M, Miyashita Y, Miwa T, Watari T, Yamaguchi T, Syutsubo K, and Hayashi K
- Abstract
Biogenic manganese oxides (BioMnOx) have been receiving increasing attention for the removal of environmental contaminants and recovery of minor metals from water environments. However, the enrichment of heterotrophic Mn(II)-oxidizing microorganisms for BioMnOx production in the presence of fast-growing coexisting heterotrophs is challenging. In our previous work, we revealed that polycaprolactone (PCL), a biodegradable aliphatic polyester, can serve as an effective solid organic substrate to enrich Mn-oxidizing microbial communities under seawater conditions. However, marine BioMnOx-producing bioreactor systems utilizing PCL have not yet been established. Therefore, a laboratory-scale continuous-flow PCL-packed aerated biofilm (PAB) reactor was operated for 238 days to evaluate its feasibility for BioMnOx production under seawater conditions. After the start-up of the reactor, the average dissolved Mn removal rates of 0.4-2.3 mg/L/day, likely caused by Mn(II) oxidation, were confirmed under different influent dissolved Mn concentrations (2.5-14.0 mg/L on average) and theoretical hydraulic retention time (0.19-0.77 day) conditions. The 16S rRNA gene amplicon sequencing analysis suggested the presence of putative Mn(II)-oxidizing and PCL-degrading bacterial lineages in the reactor. Two highly dominant operational units (OTUs) in the packed PCL-associated biofilm were assigned to the genera Marinobacter and Pseudohoeflea , whereas the genus Lewinella and unclassified Alphaproteobacteria OTUs were highly dominant in the MnOx-containing black/dark brown precipitate-associated biofilm formed in the reactor. Excitation-emission matrix fluorescence spectroscopy analysis revealed the production of tyrosine- and tryptophane-like components, which may serve as soluble heterotrophic organic substrates in the reactor. Our findings indicate that PAB reactors are potentially applicable to BioMnOx production under seawater conditions., Competing Interests: Conflict of interestThe authors declare no conflict of interest., (© King Abdulaziz City for Science and Technology 2022.)
- Published
- 2022
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12. Water quality assessment and pollution threat to safe water supply for three river basins in Malaysia.
- Author
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Loi JX, Chua ASM, Rabuni MF, Tan CK, Lai SH, Takemura Y, and Syutsubo K
- Subjects
- Ammonia, Environmental Monitoring methods, Humans, Malaysia, Water Pollution analysis, Water Quality, Water Supply, Rivers, Water Pollutants, Chemical analysis
- Abstract
Pollution in raw water poses increasing threats to safe water supply in many developing countries. Therefore, a comprehensive water quality assessment is essential to provide various stakeholders the information to deal with this problem. This study applies chemometrics to interpret a recent 10-year water quality data from three major river basins (Selangor River basin, Langat River basin, and Klang River basin) frequented by water supply disruptions in Selangor, Malaysia. We present the application of selected chemometrics approaches, namely agglomerative hierarchical cluster analysis, principal component analysis, factor analysis and Man-Kendall trend analysis. The results showed three spatial groups of monitoring stations with similar land use practices and pollution characteristics. Besides spatial differences, periodic variations were observed when similar pollutants exhibited different pollution loads during rainy and dry periods. We found that nitrogen species, total suspended solids, and dissolved solids represented the major pollution loads in the studied basins. The results further confirmed a significant increasing trend in ammonia pollution. Our study demonstrates how ammonia pollutant is likely to pose a threat to water supply and highlights the vulnerability of Selangor's water resource system to water pollution. The results of this study could facilitate decision making towards more holistic strategies, specifically, incorporating ammonia treatment facilities into the conventional water treatment plant will help achieve smooth water supply operations., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)
- Published
- 2022
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13. Suppression of phosphorus release from eutrophic lake sediments by sediment microbial fuel cells.
- Author
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Takemura Y, Syutsubo K, and Kubota K
- Subjects
- China, Lakes, Water chemistry, Bioelectric Energy Sources, Eutrophication, Geologic Sediments chemistry, Phosphorus analysis, Water Pollutants, Chemical analysis
- Abstract
Sediment microbial fuel cells (SMFCs) have served as an alternative technique to suppress phosphorus release from lake sediments to water bodies and thus mitigate eutrophication. However, the phosphorus regulation mechanism remains unclear. The purpose of this research was to understand the electrochemical influence of an SMFC on the phosphorus concentration in interstitial water. In this study, a lab-scale SMFC was applied to acetate-spiked sediments (ace+) and unspiked sediments (sed) with closed-circuit (CC)/open-circuit (OC) columns, and the circuitry was switched to investigate the relationship between electron transfer and phosphorus concentration. The dissolved total phosphorus (DTP) concentration in the sediment interstitial water in CC columns significantly decreased to below 0.1 mg/L, whereas the DTP in OC columns remained high for nine weeks. After switching the circuit, the DTP in OC→CC columns dropped but that in CC→OC columns increased within one week. At the end of the experimental period, the DTP concentrations in CC/sed, CC/ace+, OC/sed, and OC/ace+ columns were 0.10 ± 0.02, 0.03 ± 0.00, 0.82 ± 0.01, and 1.66 ± 0.12 mg/L, respectively. The respective estimated anode capacitances of those columns were 2.05 ± 0.49, 5.15 ± 0.14, 0.72 ± 0.19, and 0.71 ± 0.12 nF. We concluded that the phosphorus may have been electrochemically attracted and retained on the anode in the sediment because the adsorbed DTP contents and the increased anode capacitances were strongly correlated. Thus, SMFCs can be used for suppressing phosphorus release from eutrophic lake sediments.
- Published
- 2022
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14. Hexavalent Chromium Removal and Prokaryotic Community Analysis in Glass Column Reactor Packed with Aspen Wood as Solid Organic Substrate.
- Author
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Aoki M, Okubo K, Kusuoka R, Watari T, Syutsubo K, and Yamaguchi T
- Subjects
- Chromium metabolism, Oxidation-Reduction, Sewage microbiology, Bioreactors microbiology, Wood metabolism
- Abstract
Microbial hexavalent chromium (Cr(VI)) reduction is a promising method for Cr(VI)-laden wastewater treatment. However, the soluble organic substrate required for heterotrophic microbial Cr(VI) reduction necessitates constant supervision, and an excessive supply of soluble organic substrate can result in deterioration of the quality of the effluent. In this study, we evaluated aspen wood, a low-cost lignocellulose biomass, as a solid organic substrate for heterotrophic Cr(VI) reduction. A laboratory-scale aspen wood-packed glass column reactor inoculated with activated sludge was operated for 148 days for evaluation. Following reactor operation, an effective average dissolved Cr(VI) removal rate of 0.75 mg L
-1 h-1 was confirmed under an average dissolved Cr(VI) loading rate of 0.90 mg L-1 h-1 . Subsequently, 16S ribosomal ribonucleic acid gene amplicon sequencing analysis revealed that the dominant prokaryotic operational taxonomic units detected in the reactor were associated with prokaryotic lineages with the capacity for lignocellulose biodegradation, Cr compound resistance, and Cr(VI) reduction. Proteobacteria and Chloroflexi were two major prokaryotic phyla in the reactor. Our data indicate that aspen wood is an effective solid organic substrate for the development of simplified, effective, and low-cost microbial Cr(VI)-removing reactors., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)- Published
- 2022
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15. Effect of formic acid inflow on microbial properties of the anaerobic granular sludge in a UASB reactor.
- Author
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Syutsubo K, Miyaoka Y, Danshita T, Takemura Y, Aoki M, Tomioka N, Sumino H, Watari T, and Yamaguchi T
- Subjects
- Anaerobiosis, Bioreactors microbiology, Formates, Methane metabolism, Waste Disposal, Fluid, Sewage microbiology, Wastewater chemistry
- Abstract
In the production of natural rubber, formate or acetate is added to the latex solution to coagulate the rubber; therefore, the wastewater contains high concentrations of organic acids, requiring the application of anaerobic treatment technology. In this study, a two-phase continuous flow experiment using a laboratory-scale upflow anaerobic sludge blanket (UASB) was conducted to investigate the influence of formate inflow on the microbial and physical characteristics of the retained granular sludge. In phase 1, acetate-based wastewater was used as feed, while in phase 2, formate-based wastewater was used as feed. In phase 1, the UASB exhibited high COD removal efficiency (97.2%); in addition, the retained sludge showed increased methane production from acetate and proliferation of acetate-utilizing Methanosaeta species. In phase 2, the UASB performed as well as phase 1, with 98.2% COD removal efficiency. Microbial community structure analysis confirmed that relatives of Methanobacterium formicicum present in the retained sludge were responsible for the degradation of formate in phase 2. However, decreased diameter and slight deterioration of granular sludge settleability were observed. In conclusion, formate inflow has low risk of interference with the process performance of the UASB, but it has negative effects on the physical properties of the granular sludge.
- Published
- 2022
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16. Sediment Microbiota in Response to Circuitry of Sediment Microbial Fuel Cells, Revealed by 16S rRNA Gene Amplicon Sequencing.
- Author
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Takemura Y, Aoki M, Tran P T, Tomioka N, Kubota K, Matsuura N, and Syutsubo K
- Abstract
Information about sediment microbiota affected by sediment microbial fuel cells (SMFC) is limited. A laboratory-scale SMFC was applied to a eutrophic lake sediment under closed-circuit/open-circuit conditions. We analyzed the prokaryotes in the sediment adhering to the anode material. The archaeal family Methanoperedenaceae was a predominant group under closed-circuit conditions.
- Published
- 2021
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17. Sequence-Specific Capture of Oligonucleotide Probes (SCOPE): a Simple and Rapid Microbial rRNA Quantification Method Using a Molecular Weight Cutoff Membrane.
- Author
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Takemura Y, Sekiguchi Y, Syutsubo K, Harada H, Omura T, Li YY, and Kubota K
- Subjects
- Membranes, Artificial, Microbiota, Molecular Weight, Archaea genetics, Bacteria genetics, Oligonucleotide Probes, RNA, Ribosomal, 16S genetics
- Abstract
A method named sequence-specific capture of oligonucleotide probes (SCOPE) was developed for quantification of microbial rRNA molecules in a multiplex manner. In this method, a molecular weight cutoff membrane (MWCOM) was used for the separation of fluorescence-labeled oligonucleotide probes hybridized with rRNA from free unhybridized probes. To demonstrate proof of concept, probes targeting bacteria or archaea at different taxonomic levels were prepared and were hybridized with rRNAs. The hybridization stringency was controlled by adjusting reaction temperature and urea concentration in the mixture. Then, the mixture was filtered through the MWCOM. The rRNA and hybridized probes collected on the MWCOM were recovered and quantified using a spectrophotometer and fluorospectrometer, respectively. The method showed high accuracy in detecting specific microbial rRNA in a defined nucleic acid mixture. Furthermore, the method was capable of simultaneous detection and quantification of multiple target rRNAs in a sample with sensitivity up to a single-base mismatch. The SCOPE method was tested and benchmarked against reverse transcription-quantitative PCR (RT-qPCR) for the quantification of Bacteria , Archaea , and some key methanogens in anaerobic sludge samples. It was observed that the SCOPE method produced more reliable and coherent results. Thus, the SCOPE method allows simple and rapid detection and quantification of target microbial rRNAs for environmental microbial population analysis without any need for enzymatic reactions. IMPORTANCE Microorganisms play integral roles in the Earth's ecosystem. Microbial populations and their activities significantly affect the global nutrient cycles. Quantification of key microorganisms provides important information that is required to understand their roles in the environment. Sequence-based analysis of microbial population is a powerful tool, but it provides information only on relative abundance of microorganisms. Hence, the development of a simpler and quick method for the quantification of microorganisms is necessary. To address the shortcomings of a variety of molecular methods reported so far, we developed a simple, rapid, accurate, and multiplexed microbial rRNA quantification method to evaluate the abundance of specific microbial populations in complex ecosystems. This method demonstrated high specificity, reproducibility, and applicability to such samples. The method is useful for quantitative detection of particular microbial members in the environment.
- Published
- 2021
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18. Detection of potentially pathogenic Arcobacter spp. in Bangkok canals and the Chao Phraya River.
- Author
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Tomioka N, Yoochatchaval W, Takemura Y, Matsuura N, Danshita T, Srisang P, Mungjomklang N, and Syutsubo K
- Subjects
- Escherichia coli genetics, Rivers, Species Specificity, Thailand, Arcobacter genetics
- Abstract
The management of pathogenic bacteria in waterways is a public health issue. Here, we investigated the concentrations of potentially pathogenic bacteria, Arcobacter spp. and Campylobacter spp., and Escherichia coli, by quantifying species-specific genes in surface water samples from canals and the Chao Phraya River from June 2017 to June 2018 in Bangkok, Thailand. We assessed the relationship between the specific bacterial concentrations, water quality, and seasonal changes. Arcobacter spp. were detected at high density in all samples and showed seasonal fluctuations according to analyses based on 16S rDNA and the invasion gene ciaB. High levels of 16S rDNA and dut gene of E. coli were detected in the polluted drainage canals. A high correlation was observed between E. coli and chemical and biochemical oxygen demand (COD and BOD), suggesting that untreated domestic wastewater was the source of the E. coli. In contrast, Arcobacter spp. were detected with high density even in water samples with relatively low COD, suggesting that Arcobacter spp. are more likely than E. coli to survive in the water environment. The analysis of 16S rDNA and ciaB gene sequence analyses indicated that the Arcobacter spp. isolated from the drainage canals were A. butzleri and A. cryaerophilus.
- Published
- 2021
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19. Differences in the isotopic signature of activated sludge in four types of advanced treatment processes at a municipal wastewater treatment plant.
- Author
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Onodera T, Komatsu K, Kohzu A, Kanaya G, Mizuochi M, and Syutsubo K
- Subjects
- Nitrification, Nitrogen, Nitrogen Isotopes analysis, Sewage, Water Purification
- Abstract
The natural abundance of stable isotopes is a powerful tool for evaluating biological reactions and process conditions. However, there are few stable isotope studies on the wastewater treatment process. This study carried out the first investigation on variations in natural abundance of carbon and nitrogen stable isotope ratios (δ
13 C and δ15 N) of activated sludge in four types of advanced treatment process (extended aeration activated sludge (EAAS), aerobic-anoxic-aerobic (A2 O), recycled nitrification-denitrification (RND), and modified Bardenpho (MB)) at a municipal wastewater treatment plant. The δ13 C and δ15 N values of influent suspended solids settled in the primary sedimentation tank (i.e., primary sludge) ranged from -25.4‰ to -24.6‰ and 0.5‰-2.9‰, respectively, during monitoring periods. The δ13 C values of the activated sludge were -24.6‰ to -23.6‰ (EAAS), -25.4‰ to -24.3‰ (A2 O), -25.7‰ to -24.9‰ (RND), and -25.7‰ to -24.3‰ (MB). The δ13 C values of the activated sludge were similar to those of influent suspended solids. However, the δ13 C values of activated sludge in EAAS was significantly higher than in A2 O, RND, and MB. Meanwhile, the δ15 N values of activated sludge were obviously higher than influent suspended solids; 5.8‰-7.5‰ (EAAS), 6.6‰-8.1‰ (A2 O), 5.5‰-7.5‰ (RND), and 5.3‰-7.6‰ (MB). Changes in δ13 C and δ15 N values of the activated sludge within the treatment system were also found. These findings indicate that changes in δ13 C and δ15 N values of the activated sludge rely on important function for biological wastewater treatment such as nitrification, denitrification, and methane oxidation through wastewater treatment over time., (Copyright © 2021 Elsevier Ltd. All rights reserved.)- Published
- 2021
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20. Evaluation of stable isotope ratios (δ 15 N and δ 18 O) of nitrate in advanced sewage treatment processes: Isotopic signature in four process types.
- Author
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Onodera T, Komatsu K, Kohzu A, Kanaya G, Mizuochi M, and Syutsubo K
- Abstract
Stable isotope ratios of nitrate are a powerful tool to evaluate aquatic environment stress from treated and untreated sewage. However, there is generally a lack of knowledge on the change in stable isotope ratios within wastewater treatment plants. We investigated nitrogen and oxygen stable isotope ratios (δ
15 N and δ18 O) of nitrate in four types of advanced treatment processes operated in parallel; (A) extended aeration activated sludge, (B) anaerobic-anoxic-aerobic (A2 O), (C) recycled nitrification-denitrification, and (D) modified Bardenpho. The results exhibited spatial variation of δ15 N and δ18 O for nitrate within the treatment steps. The changes in δ15 N and δ18 O may result from the reactor conditions (aerobic, anoxic, and anaerobic) and the order of these processes. As decreasing nitrate concentration in the anoxic stages, the δ15 N/δ18 O ratio for nitrate increased at a rate of 1.3 to 1.6 coupling with the reduction in the nitrate concentration in the anoxic stages. The δ15 N and δ18 O signatures were attributed to process performance in regard to nitrogen removal. In particular, the modified Bardenpho process has higher nitrogen removal efficiency over other processes, producing effluent with lower nitrate concentration and higher stable isotopes (δ15 N: 23.6 to 25.5‰, δ18 O: 2.8 to 4.5‰). We concluded that the stable isotope signatures mirrored the treatment efficiency and effluent characteristics., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)- Published
- 2021
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21. Microbial properties of the granular sludge in a psychrophilic UASB reactor fed with electronics industry wastewater containing organic chemicals.
- Author
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Syutsubo K, Danshita T, Sumino H, Iguchi A, and Takemura Y
- Subjects
- 2-Propanol analysis, 2-Propanol isolation & purification, 2-Propanol metabolism, Bacteria isolation & purification, Bacteria metabolism, Ethanolamine analysis, Ethanolamine isolation & purification, Ethanolamine metabolism, Quaternary Ammonium Compounds analysis, Quaternary Ammonium Compounds isolation & purification, Quaternary Ammonium Compounds metabolism, Wastewater chemistry, Bioreactors microbiology, Electronics, Microbiota physiology, Sewage microbiology, Waste Disposal, Fluid methods
- Abstract
In this study, a lab-scale upflow anaerobic sludge blanket (UASB) reactor was applied to the treatment of artificial electronics industry wastewater containing tetramethylammonium-hydroxide (TMAH), monoethanolamine (MEA), and isopropyl-alcohol (IPA) in order to evaluate process performance and degradation properties. During 800 days of operation, 96% efficiency of chemical oxygen demand (COD) removal was stably achieved at an organic loading rate of 8.5 kgCOD/m
3 /day at 18-19 °C. MEA degradation, carried out by acid-forming eubacteria, was confirmed within a week. The physical properties of the retained granular sludge were degraded by feeding with TMAH wastewater, but maintained by feeding with MEA wastewater due to an accumulation of species from the genus Methanosaeta and family Geobacteraceae . Analysis of the microbial community structure via SEM and 16S rRNA genes showed a proliferation of Methanomethylovorans -like cells and Methanosaeta -like cells at the surface and in the core of the granular sludge with TMAH, MEA and IPA acclimation. Furthermore, a batch degradation experiment confirmed that process inhibition due to increasing chemical concentration was relatively stronger for TMAH than for MEA or IPA. Thus, controlling the TMAH concentration of the influent to below 1 gCOD/L will be important for the stable treatment of electronics industry wastewater by UASB technology.- Published
- 2021
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22. Characterization of dissolved organic matter in wastewater during aerobic, anaerobic, and anoxic treatment processes by molecular size and fluorescence analyses.
- Author
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Komatsu K, Onodera T, Kohzu A, Syutsubo K, and Imai A
- Subjects
- Anaerobiosis, Factor Analysis, Statistical, Humic Substances, Sewage, Spectrometry, Fluorescence, Organic Chemicals, Wastewater
- Abstract
Changes in the characteristics of dissolved organic matter (DOM: the dissolved fraction of natural organic matter) during a series of wastewater treatment plant (WWTP) processes were investigated by using a combination of molecular size analysis and excitation emission matrix (EEM) spectroscopy coupled with parallel factor analysis. The characteristics of DOM were compared following aerobic, anoxic, and anaerobic treatments. Three peaks at about 100,000 Da (high-molecular-size DOM, Peak 1) and about 900-1,100 Da (intermediate-molecular-size DOM, Peak 2; low-molecular-size DOM, Peak 3 as the shoulder of Peak 2) were observed in the distribution of total organic carbon molecular sizes in the influent of the WWTPs. In this study, five fluorescent components (C1 to C5) were identified in the EEM spectra. Molecular size analysis and molecular size fractionation revealed that the C3 (humic-like) and C5 (specific to sewage) fluorophores had intermediate or low molecular sizes. Comparison of the changes of the concentrations of dissolved organic carbon in each reaction tank and investigation of the removal selectivity of each treatment (aerobic, anaerobic, and anoxic) suggested that the heterogenous compounds present in DOM of the influent were homogenized into intermediate-molecular-size DOM with high hydrophobicity and aromaticity, or into C4 fluorophores (DOM-X), during anaerobic or anoxic treatment. DOM-X was able to be transformed or removed by aerobic treatment. The results suggested that introduction of aerobic treatment at the appropriate stage of wastewater treatment or inclusion of physical or chemical treatment should be an effective way to optimize DOM removal., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)
- Published
- 2020
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23. Distribution in natural abundances of stable isotopes of nitrate and retained sludge in a nitrifying bioreactor: Drastic changes in isotopic signatures.
- Author
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Onodera T, Kanaya G, Kohzu A, and Syutsubo K
- Subjects
- Bioreactors, Environmental Monitoring, Nitrates, Nitrogen Isotopes, Oxygen Isotopes, Sewage
- Abstract
This study determined the spatial and temporal changes in natural abundance of stable isotopes (δ
13 C, δ15 N, and δ18 O) with regard to nitrate (NO3 - ) and retained sludge in a nitrifying bioreactor. The bioreactor was continuously fed with synthetic wastewater including ammonium for 61 days at 20 °C. After the start-up period of the bioreactor, the NO3 - concentration in the effluent gradually increased. The stable isotopes (δ15 N and δ18 O) of NO3 - in the effluent also increased in a phase of incomplete nitrification. The profile experiments showed that the concentration and stable isotopes of NO3 - changed simultaneously along the wastewater flow in the bioreactor. The stable isotope analysis revealed that nitrification efficiency seems to be strongly related to the δ15 N of NO3 - . Moreover, the δ13 C and δ15 N of the retained sludge drastically changed along the reactor length, from -26‰ to -18‰ and from 5‰ to 30‰, respectively, after 61 days of operation. The isotopic composition of the retained sludge might be affected by the isotope ratios (δ15 N and δ18 O) of NO3 - in the bioreactor. Therefore, the isotope signatures of the retained sludge seem to closely reflect process performance such as nitrification efficiency throughout the operational period. Our findings suggest that the spatial distribution of the isotopic composition of the retained sludge can be used to detect process occurrence within the bioreactor over time., (Copyright © 2019 Elsevier B.V. All rights reserved.)- Published
- 2020
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24. Performance evaluation of a down-flow hanging sponge (DHS) reactor as a decentralized domestic wastewater treatment system in tropical regions.
- Author
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Danshita T, Yoochatchaval W, Takemura Y, Miyaoka Y, Kada M, Tepjun W, Thonglee S, Sonaka H, Yamaguchi T, Tomioka N, Banjongproo P, Okadera T, Ebie Y, and Syutsubo K
- Subjects
- Biological Oxygen Demand Analysis, Denitrification, Pilot Projects, Sewage microbiology, Thailand, Bioreactors, Wastewater chemistry, Water Purification methods
- Abstract
In this study, a pilot-scale down-flow hanging sponge (DHS) reactor was operated in the community plant of Bangkok for the treatment of domestic wastewater (COD 285 mg/L, BOD 105 mg/L) collected by separate sewer to evaluate the reactor's feasibility as a decentralized treatment system. The DHS reactor was operated for 600 days at ambient temperatures of 25-30 °C, both with constant flow conditions and with fluctuating flow conditions that simulated wastewater discharge patterns of the community. The results indicate that under constant flow at an HRT of 5 h, the volumetric loading rates of 0.36 kgBOD/m
3 -sponge/day and 0.16 kgN/m3 -sponge/day were the optimum operational conditions of the DHS reactor in order to satisfy the effluent discharge standards. The DHS achieved removal rates of 89, 95, 91 and 90% for COD, BOD, TSS and NH4 -N. Under the fluctuating flow condition, improvement of denitrification was confirmed at volumetric loading rates of 0.50 kgBOD/m3 -sponge/day and 0.18 kgN/m3 -sponge/day. The fluctuating flow of wastewater positively affects retained sludge activities in terms of homogenizing sludge concentration and stimulating oxygen uptake rates. These results suggest that the DHS reactor can be applied as a decentralized treatment system for domestic wastewater with fluctuating flow rates in tropical regions.- Published
- 2020
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25. Characteristics of greenhouse gas emissions from an anaerobic wastewater treatment system in a natural rubber processing factory.
- Author
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Tanikawa D, Watari T, Mai TC, Fukuda M, Syutsubo K, Nguyen NB, and Yamaguchi T
- Subjects
- Anaerobiosis, Methane, Nitrous Oxide, Rubber, Vietnam, Waste Disposal, Fluid, Greenhouse Gases, Wastewater
- Abstract
Greenhouse gas (GHG) emissions from both open-type and closed anaerobic wastewater treatment systems in a natural rubber processing factory in Vietnam were surveyed. In this factory, wastewater was treated by an open-type anaerobic baffled reactor (OABR) that comprised 60 compartments. A part of the wastewater was fed to a pilot-scale up-flow anaerobic sludge blanket (UASB) reactor to enable a comparison of the process performance and GHG emission characteristics with those of the OABR. In the OABR, 94.4% of the total chemical oxygen demand (COD) and 18.1% of ammonia nitrogen was removed. GHGs emitted from the OABR included both methane and nitrous oxide. The total GHGs emitted from the OABR was 0.153 t-CO
2 eq/m3 -wastewater. Nitrous oxide accounted for approximately 65% of the total GHGs emitted from the OABR. By contrast, 99.6% of the methane emission and 99.9% of nitrous oxide emission were reduced by application of the UASB. However, the ammonia removal efficiency of the UASB was only 2.2%. Furthermore, Acinetobacter johnsonii , which is known as a heterotrophic ammonia remover, was detected only in the OABR. These results indicated that high nitrous oxide emissions were caused by denitrification in the OABR and that application of the closed anaerobic system could drastically reduce the emissions of both methane and nitrous oxide.- Published
- 2019
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26. Biological treatment of electronic industry wastewater containing TMAH, MEA and sulfate in an UASB reactor.
- Author
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Urasaki K, Sumino H, Danshita T, Yamaguchi T, and Syutsubo K
- Subjects
- Euryarchaeota metabolism, Sewage chemistry, Sewage microbiology, Bioreactors microbiology, Ethanolamine analysis, Quaternary Ammonium Compounds analysis, Sulfates analysis, Wastewater chemistry, Water Pollutants, Chemical analysis, Water Purification methods
- Abstract
This study investigated the feasibility of the methanogenic treatment of electronic industry wastewater containing tetramethylammonium hydroxide (TMAH), monoethanolamine (MEA) and sulfate in a lab-scale mesophilic up-flow anaerobic sludge blanket reactor. Feeding a mixture of electronic industry wastewater and co-substrate organics to the reactor for smooth acclimatization of sludge gave complete degradation of each organics within five days. When the reactor was fed only electronic industry wastewater, total COD removal, TMAH removal and MEA removal were achieved over 80, 99 and 99%, respectively, at an organic loading rate of 11.5 kg-COD m
-3 day-1 . 173 mg-S L-1 of influent sulfate was almost reduced simultaneously with the COD removal. In order to evaluate performance stability, the TMAH shock load event was performed under the conditions of 11,000 mg-COD L-1 for 24 h. Inflow of high TMAH concentration inhibited TMAH degradation and sulfate reduction for more than one month, however, not MEA. The batch feeding experiment and specific activity measurement revealed degradation pathways of each organics. TMAH was degraded via methanogenic pathway without sulfate reduction, MEA was degraded via methanogenic pathway with sulfate reduction. The results indicated that methanogenic treatment was applicable to electronic industry wastewater by appropriate reactor handling.- Published
- 2019
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27. Evaluation of trophic transfer in the microbial food web during sludge degradation based on 13 C and 15 N natural abundance.
- Author
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Onodera T, Kanaya G, Hatamoto M, Kohzu A, Iguchi A, Takimoto Y, Yamaguchi T, Mizuochi M, and Syutsubo K
- Subjects
- Carbon Isotopes, Nitrogen Isotopes, Wastewater, Food Chain, Sewage
- Abstract
Carbon and nitrogen stable isotope ratios (δ
13 C and δ15 N) were determined in activated sludge, which was exposed to endogenous conditions for 36 days and contained a wide diversity of organisms across several trophic levels. The aim of this study was to elucidate the fluctuation of δ13 C and δ15 N through trophic transfer in the microbial consortia. The sludge was evaluated in view of sludge mass, bacterial community, higher trophic organisms, sludge δ13 C and δ15 N, and δ15 N and δ18 O of nitrate. The results show that the activated sludge became more enriched with15 N as degradation proceeded. Eventually, the mixed liquor volatile suspended solid concentrations in the activated sludge decreased from 1610 to 710 mg/L and the δ15 N of the sludge increased from 8.3‰ to 10.8‰. In contrast, the δ13 C values of the sludge were stable. Microscope observations confirmed that consumers such as Rotifera, Tardigrada and Annelida (Aelosoma sp.) were present in the activated sludge for the entire operational period. The abundance of those organisms drastically changed during the operational periods, and the diversity in bacterial community also changed, resulting in community succession. Changes in biotic community, reduction in sludge mass, and increase in δ15 N of the sludge occurred during the sludge degradation processes. This implies that the sludge degradation was partly caused by the trophic conversion of the sludge-derived nitrogen in the food web. The δ15 N of the sludge can be used as an indicator of the sludge degradation through trophic transfer in wastewater treatment reactors. These findings provide new insights into understanding trophic transfer during microbial community succession and the effects of the feeding process on sludge degradation., (Copyright © 2018 Elsevier Ltd. All rights reserved.)- Published
- 2018
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28. Evaluation of process performance and retained sludge properties of a psychrophilic UASB reactor for treatment of iso-plophyl alcohol (2-propanol)-containing wastewater.
- Author
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Danshita T, Miyaoka Y, Sumino H, Iguchi A, Yamaguchi T, and Syutsubo K
- Subjects
- Archaea metabolism, Methane metabolism, Methanospirillum isolation & purification, Methanospirillum metabolism, RNA, Ribosomal, 16S genetics, RNA, Ribosomal, 16S isolation & purification, Waste Disposal, Fluid methods, Water Quality, 2-Propanol analysis, Archaea isolation & purification, Bioreactors microbiology, Sewage chemistry
- Abstract
In this study, a continuous feeding experiment was conducted with synthetic iso-plophyl alcohol (2-propanol)-containing wastewater using a lab-scale psychrophilic UASB reactor to evaluate process performance and retained sludge properties. For smooth acclimation, methanogenic granular sludge was seeded and a proportion of 2-propanol in the synthetic wastewater containing sucrose and volatile fatty acids was increased stepwise from 0% to 30%, 60% and then 90% of COD (chemical oxygen demand). As a result, after a 4-week period for acclimation to 2-propanol degradation, a COD removal rate of 95% was achieved at an organic loading rate (OLR) of 8.4 kg COD/m
3 /day. Additionally, the physical properties of the retained granular sludge were maintained even when the reactor was supplied with 2-propanol-rich wastewater for more than 200 days. From the batch assays using serum bottles, methanogenic degradation of 2-propanol was observed with acetone accumulation. By comparison, 2-propanol degradation was clearly inhibited in the presence of chloroform as a specific inhibitor of methanogen. A domain archaeal community structure analysis targeting 16S rRNA genes showed the relative abundance of the genus Methanospillium was increased in the 2-propanol acclimated sludge. These results suggested Methanospillium related species in the granular sludge appreciably contributed to the direct degradation of 2-proapanol into acetone under an anaerobic condition.- Published
- 2018
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29. Influence of tetramethylammonium hydroxide (TMAH) on the microbial properties of anaerobic granular sludge acclimated to isoplophyl alcohol (IPA) wastewater under psychrophilic conditions.
- Author
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Danshita T, Miyaoka Y, Matsuura N, Sumino H, Yamaguchi T, and Syutsubo K
- Subjects
- Acclimatization drug effects, Anaerobiosis drug effects, Archaea growth & development, Archaea metabolism, Bioreactors microbiology, Ethanol chemistry, Ethanolamine chemistry, Euryarchaeota growth & development, Euryarchaeota metabolism, Methane chemistry, Temperature, Waste Disposal, Fluid methods, 2-Propanol chemistry, Methane metabolism, Quaternary Ammonium Compounds pharmacology, Sewage microbiology, Wastewater chemistry, Wastewater microbiology
- Abstract
In this study, a continuous flow experiment was conducted in which a lab-scale upflow anaerobic sludge blanket (UASB) reactor at psychrophilic conditions (18-19°C) was fed with artificial wastewater, containing tetramethylammonium hydroxide (TMAH) and isoplophyl alcohol (IPA), from the electronics industry. This was done to evaluate process performance and microbial properties of the granular sludge that was retained in the reactor. The inoculated granular sludge was precultured with IPA containing wastewater but not TMAH; as a result, no degradation was observed in 30 days of operation. To enhance degradation, the reactor was seeded with 2% weight of the TMAH-enriched sludge, after which TMAH was enhanced. Consequently, the total COD removal efficiency reached 90% at an organic loading rate of 7.5 kg COD/m
3 /day. The TMAH inflow decreased the diameter of the retained granular sludge, but the sludge retained its settleability. The proliferation of the Methanometylovorans microorganisms present in the enrichment culture was confirmed by analysis of the 16 S rRNA gene in the retained sludge. In addition, TMAH degradation was inhibited by addition chloroform, a methanogen inhibitor. These results suggested species in the genus Methanometylovorans in the granular sludge contributed significantly to methanogenic TMAH degradation.- Published
- 2018
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30. Evaluation of the process performance of a down-flow hanging sponge reactor for direct treatment of domestic wastewater in Bangkok, Thailand.
- Author
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Miyaoka Y, Yoochatchaval W, Sumino H, Banjongproo P, Yamaguchi T, Onodera T, Okadera T, and Syutsubo K
- Subjects
- Biological Oxygen Demand Analysis, Cities, Eukaryota genetics, Nitrogen analysis, Phylogeny, RNA, Ribosomal, 18S genetics, Sewage microbiology, Thailand, Water Purification instrumentation, Bioreactors microbiology, Wastewater chemistry, Water Purification methods
- Abstract
This study assesses the performance of an aerobic trickling filter, down-flow hanging sponge (DHS) reactor, as a decentralized domestic wastewater treatment technology. Also, the characteristic eukaryotic community structure in DHS reactor was investigated. Long-term operation of a DHS reactor for direct treatment of domestic wastewater (COD = 150-170 mg/L and BOD = 60-90 mg/L) was performed under the average ambient temperature ranged from 28°C to 31°C in Bangkok, Thailand. Throughout the evaluation period of 550 days, the DHS reactor at a hydraulic retention time of 3 h showed better performance than the existing oxidation ditch process in the removal of organic carbon (COD removal rate = 80-83% and BOD removal rate = 91%), nitrogen compounds (total nitrogen removal rate = 45-51% and NH
4 + -N removal rate = 95-98%), and low excess sludge production (0.04 gTS/gCOD removed). The clone library based on the 18S ribosomal ribonucleic acid gene sequence revealed that phylogenetic diversity of 18S rRNA gene in the DHS reactor was higher than that of the present oxidation ditch process. Furthermore, the DHS reactor also demonstrated sufficient COD and NH4 + -N removal efficiency under flow rate fluctuation conditions that simulates a small-scale treatment facility. The results show that a DHS reactor could be applied as a decentralized domestic wastewater treatment technology in tropical regions such as Bangkok, Thailand.- Published
- 2017
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31. Performance evaluation of the pilot scale upflow anaerobic sludge blanket - Downflow hanging sponge system for natural rubber processing wastewater treatment in South Vietnam.
- Author
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Watari T, Mai TC, Tanikawa D, Hirakata Y, Hatamoto M, Syutsubo K, Fukuda M, Nguyen NB, and Yamaguchi T
- Subjects
- Anaerobiosis, Bioreactors, Rubber, Vietnam, Sewage, Waste Disposal, Fluid, Wastewater
- Abstract
A pilot-scale upflow anaerobic sludge blanket (UASB)-downflow hanging sponge system (DHS) combined with an anaerobic baffled reactor (ABR) and a settling tank (ST) was installed in a natural rubber processing factory in South Vietnam and its process performance was evaluated for 267days. The UASB reactor achieved a total removal efficiency of 55.6±16.6% for chemical oxygen demand (COD) and 77.8±10.3% for biochemical oxygen demand (BOD) with an organic loading rate of 1.7±0.6kg-COD·m
-3 ·day-1 . The final effluent of the proposed system had 140±64mg·L-1 of total COD, 31±12mg·L-1 of total BOD, and 58±24mg-N·L-1 of total nitrogen. The system could significantly reduce 92% of greenhouse gas emissions and 80% of hydraulic retention times compared with current treatment systems., (Copyright © 2017. Published by Elsevier Ltd.)- Published
- 2017
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32. Eukaryotic Community Shift in Response to Organic Loading Rate of an Aerobic Trickling Filter (Down-Flow Hanging Sponge Reactor) Treating Domestic Sewage.
- Author
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Miyaoka Y, Hatamoto M, Yamaguchi T, and Syutsubo K
- Subjects
- Alveolata classification, Animals, Bacteria growth & development, Bacteria metabolism, Cell Count, Eukaryota genetics, Eukaryota growth & development, Eukaryota metabolism, Porifera, RNA, Ribosomal, 18S genetics, Rhizaria classification, Waste Disposal, Fluid, Water Purification, Water Quality, Aerobiosis, Bioreactors microbiology, Bioreactors parasitology, Eukaryota classification, Sewage microbiology, Sewage parasitology
- Abstract
In this study, changes in eukaryotic community structure and water quality were investigated in an aerobic trickling filter (down-flow hanging sponge, DHS) treating domestic sewage under different organic loading rates (OLRs). The OLR clearly influenced both sponge pore water quality and relative flagellates and ciliates (free-swimming, carnivorous, crawling, and stalked protozoa) abundances in the retained sludge. Immediately after the OLR was increased from 1.05 to 1.97 kg chemical oxygen demand (COD) m
-3 day-1 , COD and NH4 + -N treatment efficiencies both deteriorated, and relative flagellates and ciliates abundances then increased from 2-8 % to 51-65 % total cells in the middle-bottom part of the DHS reactor. In a continuous operation at a stable OLR (2.01 kg COD m-3 day-1 ), effluent water quality improved, and relative flagellates and ciliates abundances decreased to 15-46 % total cells in the middle-bottom part of the DHS reactor. This result may indicate that flagellates and ciliates preferentially graze on dispersed bacteria, thus, stabilizing effluent water quality. Additionally, to investigate eukaryotic community structure, clone libraries based on the 18S ribosomal ribonucleic acid (rRNA) gene of the retained sludge were constructed. The predominant group was Nucletmycea phylotypes, representing approximately 29-56 % total clones. Furthermore, a large proportion of the clones had <97 % sequence identity in the NCBI database. This result indicates that phylogenetically unknown eukaryotes were present in the DHS reactor. These results provide insights into eukaryotic community shift in the DHS reactor treating domestic sewage.- Published
- 2017
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33. Development of downflow hanging sponge (DHS) reactor as post treatment of existing combined anaerobic tank treating natural rubber processing wastewater.
- Author
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Watari T, Cuong Mai T, Tanikawa D, Hirakata Y, Hatamoto M, Syutsubo K, Fukuda M, Nguyen NB, and Yamaguchi T
- Subjects
- Anaerobiosis, Bacteria genetics, Bacteria metabolism, Nitrification, Nitrogen analysis, RNA, Ribosomal, 16S, Sewage microbiology, Waste Disposal, Fluid, Bioreactors microbiology, Industrial Waste analysis, Rubber chemistry, Wastewater
- Abstract
Conventional aerated tank technology is widely applied for post treatment of natural rubber processing wastewater in Southeast Asia; however, a long hydraulic retention time (HRT) is required and the effluent standards are exceeded. In this study, a downflow hanging sponge (DHS) reactor was installed as post treatment of anaerobic tank effluent in a natural rubber factory in South Vietnam and the process performance was evaluated. The DHS reactor demonstrated removal efficiencies of 64.2 ± 7.5% and 55.3 ± 19.2% for total chemical oxygen demand (COD) and total nitrogen, respectively, with an organic loading rate of 0.97 ± 0.03 kg-COD m
-3 day-1 and a nitrogen loading rate of 0.57 ± 0.21 kg-N m-3 day-1 . 16S rRNA gene sequencing analysis of the sludge retained in the DHS also corresponded to the result of reactor performance, and both nitrifying and denitrifying bacteria were detected in the sponge carrier. In addition, anammox bacteria was found in the retained sludge. The DHS reactor reduced the HRT of 30 days to 4.8 h compared with the existing algal tank. This result indicates that the DHS reactor could be an appropriate post treatment for the existing anaerobic tank for natural rubber processing wastewater treatment.- Published
- 2017
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34. Development of a BR-UASB-DHS system for natural rubber processing wastewater treatment.
- Author
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Watari T, Thanh NT, Tsuruoka N, Tanikawa D, Kuroda K, Huong NL, Tan NM, Hai HT, Hatamoto M, Syutsubo K, Fukuda M, and Yamaguchi T
- Abstract
Natural rubber processing wastewater contains high concentrations of organic compounds, nitrogen, and other contaminants. In this study, a treatment system composed of a baffled reactor (BR), an upflow anaerobic sludge blanket (UASB) reactor, and a downflow hanging sponge (DHS) reactor was used to treat natural rubber processing wastewater in Vietnam. The BR showed good total suspended solids (TSS) removal of 47.6%, as well as acidification of wastewater. The UASB reactor achieved a high chemical oxygen demand (COD) removal efficiency of 92.7 ± 2.3% and energy recovery in the form of methane with an organic loading rate of 12.2 ± 6.6 kg-COD m
-3 day-1 . The DHS reactor showed high performance in residual organic matter removal from UASB effluent. In total, the system achieved high-level total COD removal of 98.6% ± 1.2% and TSS removal of 98.0% ± 1.4%. Massive parallel 16S rRNA gene sequencing of the retained sludge in the UASB reactor showed the predominant microbial phyla to be Bacteroidetes, Firmicutes, Proteobacteria, WWE1, and Euryarchaeota. Uncultured bacteria belonging to the phylum Bacteroidetes and Phylum WWE1 were predominant in the UASB reactor. This microbial assemblage utilizes the organic compounds contained in natural rubber processing wastewater. In addition, the methane-producing archaea Methanosaeta sp. and Methanolinea sp. were detected.- Published
- 2016
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35. 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.
- Author
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Thanh NT, Watari T, Thao TP, Hatamoto M, Tanikawa D, Syutsubo K, Fukuda M, Tan NM, Anh TK, Yamaguchi T, and Huong NL
- Subjects
- Aluminum Chloride, Anaerobiosis, Bacteria genetics, Bacteria metabolism, Bioreactors, RNA, Bacterial genetics, RNA, Bacterial metabolism, RNA, Ribosomal, 16S genetics, RNA, Ribosomal, 16S metabolism, Rubber, Waste Disposal, Fluid instrumentation, Aluminum Compounds analysis, Chlorides analysis, Industrial Waste analysis, Microbiota drug effects, Sewage microbiology, Waste Disposal, Fluid methods, Water Pollution, Chemical analysis
- Abstract
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.
- Published
- 2016
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36. Characterization of wastewater treatment by two microbial fuel cells in continuous flow operation.
- Author
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Kubota K, Watanabe T, Yamaguchi T, and Syutsubo K
- Subjects
- Biological Oxygen Demand Analysis, Bioreactors, Fermentation, Molasses analysis, Bioelectric Energy Sources, Methane metabolism, Waste Disposal, Fluid methods, Wastewater analysis
- Abstract
A two serially connected single-chamber microbial fuel cell (MFC) was applied to the treatment of diluted molasses wastewater in a continuous operation mode. In addition, the effect of series and parallel connection between the anodes and the cathode on power generation was investigated experimentally. The two serially connected MFC process achieved 79.8% of chemical oxygen demand removal and 11.6% of Coulombic efficiency when the hydraulic retention time of the whole process was 26 h. The power densities were 0.54, 0.34 and 0.40 W m(-3) when electrodes were in individual connection, serial connection and parallel connection modes, respectively. A high open circuit voltage was obtained in the serial connection. Power density decreased at low organic loading rates (OLR) due to the shortage of organic matter. Power generation efficiency tended to decrease as a result of enhancement of methane fermentation at high OLRs. Therefore, high power density and efficiency can be achieved by using a suitable OLR range.
- Published
- 2016
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37. High organic loading treatment for industrial molasses wastewater and microbial community shifts corresponding to system development.
- Author
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Kuroda K, Chosei T, Nakahara N, Hatamoto M, Wakabayashi T, Kawai T, Araki N, Syutsubo K, and Yamaguchi T
- Subjects
- Biological Oxygen Demand Analysis, Molasses, Bioreactors microbiology, Microbial Consortia, RNA, Ribosomal, 16S genetics, Wastewater chemistry, Water Purification methods
- Abstract
Molasses wastewater contains high levels of organic compounds, cations, and anions, causing operational problems for anaerobic biological treatment. To establish a high organic loading treatment system for industrial molasses wastewater, this study designed a combined system comprising an acidification tank, a thermophilic multi-stage (MS)-upflow anaerobic sludge blanket (UASB) reactor, mesophilic UASB reactor, and down-flow hanging sponge reactor. The average total chemical oxygen demand (COD) and biochemical oxygen demand removal rates were 85%±3% and 95%±2%, respectively, at an organic loading rate of 42kgCODcrm(-3)d(-1) in the MS-UASB reactor. By installation of the acidification tank, the MS-UASB reactor achieved low H2-partial pressure. The abundance of syntrophs such as fatty acid-degrading bacteria increased in the MS-UASB and 2nd-UASB reactors. Thus, the acidification tank contributed to maintaining a favorable environment for syntrophic associations. This study provides new information regarding microbial community composition in a molasses wastewater treatment system., (Copyright © 2015. Published by Elsevier Ltd.)
- Published
- 2015
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38. Recovery and biological oxidation of dissolved methane in effluent from UASB treatment of municipal sewage using a two-stage closed downflow hanging sponge system.
- Author
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Matsuura N, Hatamoto M, Sumino H, Syutsubo K, Yamaguchi T, and Ohashi A
- Subjects
- Air Pollutants isolation & purification, Humans, Methane isolation & purification, Oxidation-Reduction, Seasons, Temperature, Waste Disposal, Fluid methods, Air Pollutants chemistry, Bacteria, Anaerobic physiology, Bioreactors, Methane chemistry, Sewage chemistry, Waste Disposal, Fluid instrumentation
- Abstract
A two-stage closed downflow hanging sponge (DHS) reactor was used as a post-treatment to prevent methane being emitted from upflow anaerobic sludge blanket (UASB) effluents containing unrecovered dissolved methane. The performance of the closed DHS reactor was evaluated using real municipal sewage at ambient temperatures (10-28 °C) for one year. The first stage of the closed DHS reactor was intended to recover dissolved methane from the UASB effluent and produce a burnable gas with a methane concentration greater than 30%, and its recovery efficiency was 57-88%, although the amount of dissolved methane in the UASB effluent fluctuated in the range of 46-68 % of methane production greatly depending on the temperature. The residual methane was oxidized and the remaining organic carbon was removed in the second closed DHS reactor, and this reactor performed very well, removing more than 99% of the dissolved methane during the experimental period. The rate at which air was supplied to the DHS reactor was found to be one of the most important operating parameters. Microbial community analysis revealed that seasonal changes in the methane-oxidizing bacteria were key to preventing methane emissions., (Copyright © 2014 Elsevier Ltd. All rights reserved.)
- Published
- 2015
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- View/download PDF
39. Protection of biomass from snail overgrazing in a trickling filter using sponge media as a biomass carrier: down-flow hanging sponge system.
- Author
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Onodera T, Syutsubo K, Yoochatchaval W, Sumino H, Mizuochi M, and Harada H
- Subjects
- Animals, Sewage, Thailand, Biomass, Bioreactors, Filtration instrumentation, Snails physiology
- Abstract
This study investigated down-flow hanging sponge (DHS) technology as a promising trickling filter (TF) using sponge media as a biomass carrier with an emphasis on protection of the biomass against macrofauna overgrazing. A pilot-scale DHS reactor fed with low-strength municipal sewage was operated under ambient temperature conditions for 1 year at a sewage treatment plant in Bangkok, Thailand. The results showed that snails (macrofauna) were present on the surface of the sponge media, but could not enter into it, because the sponge media with smaller pores physically protected the biomass from the snails. As a result, the sponge media maintained a dense biomass, with an average value of 22.3 gVSS/L sponge (58.1 gTSS/L sponge) on day 370. The snails could graze biomass on the surface of the sponge media. The DHS reactor process performance was also successful. The DHS reactor requires neither chemical treatments nor specific operations such as flooding for snail control. Overall, the results of this study indicate that the DHS reactor is able to protect biomass from snail overgrazing.
- Published
- 2015
- Full Text
- View/download PDF
40. Spatial changes in carbon and nitrogen stable isotope ratios of sludge and associated organisms in a biological sewage treatment system.
- Author
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Onodera T, Kanaya G, Syutsubo K, Miyaoka Y, Hatamoto M, and Yamaguchi T
- Subjects
- Anaerobiosis, Animals, Bioreactors, Carbon Isotopes analysis, Filtration, Larva metabolism, Nitrification, Nitrogen Isotopes analysis, Water Purification methods, Diptera chemistry, Oligochaeta chemistry, Sewage analysis, Waste Disposal, Fluid methods
- Abstract
Carbon and nitrogen stable isotope ratios (δ¹³C and δ¹⁵N) have been utilized as powerful tools for tracing energy or material flows within food webs in a range of environmental studies. However, the techniques have rarely been applied to the study of biological wastewater treatment technologies. We report on the spatial changes in δ¹³C and δ¹⁵N in sludge and its associated biotic community in a wastewater treatment system. This system consisted of an upflow anaerobic sludge blanket (UASB) and a down-flow hanging sponge (DHS) which is a novel type of trickling filter. The results showed clear spatial changes in the δ¹³C and δ¹⁵N of suspended solids (SS), retained sludge, and macrofauna (oligochaetes and fly larvae) in the system. The δ¹³C and δ¹⁵N was used as a natural tracer to determine the SS dynamic throughout the system. The results imply that SS in the DHS effluent was mainly eluted from the retained sludge in the lower section of the DHS reactor. The δ¹⁵N of the retained sludge in the DHS reactor increased drastically from the inlet towards to the outlet, from -0.7‰ to 10.3‰. This phenomenon may be attributed to nitrogen conversion processes (i.e. nitrification and denitrification). The δ¹⁵N of oligochaetes also increased from the inlet to the outlet, which corresponded well to that of the retained sludge. Thus, the δ¹⁵N of the oligochaetes might simply mirror the δ¹⁵N of the retained sludge. On the other hand, the δ¹³C and δ¹⁵N of sympatric fly larvae differed from those of the oligochaetes sampled, indicating dietary differences between the taxa. Therefore δ¹³C and δ¹⁵N reflected both treatment and dietary characteristics. We concluded that δ¹³C and δ¹⁵N values are potentially useful as alternative indicators for investigating microbial ecosystems and treatment characteristics of biological wastewater treatment systems.
- Published
- 2015
- Full Text
- View/download PDF
41. Pilot-scale experiment of down-flow hanging sponge for direct treatment of low-strength municipal wastewater in Bangkok, Thailand.
- Author
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Onodera T, Yoochatchaval W, Sumino H, Mizuochi M, Okadera T, Fujita T, Banjongproo P, and Syutsubo K
- Subjects
- Biological Oxygen Demand Analysis, Equipment Design, Pilot Projects, Sewage, Thailand, Bioreactors, Waste Disposal, Fluid methods, Wastewater
- Abstract
A pilot-scale experiment of a down-flow hanging sponge (DHS) reactor for treatment of low-strength municipal wastewater was conducted over 1 year in Bangkok, Thailand, to establish an appropriate method for treatment under tropical climate conditions. Municipal wastewater with an average BOD of 19 mg/L was fed directly into the DHS reactor. Superior effluent quality (5.1 ± 3.4 mg/L TSS, 21.1 ± 9.0 mg/L COD, 2.8 ± 1.4 mg/L BOD, and 4.1 ± 1.0 mg/L TN) was achieved at a hydraulic retention time (HRT) of 1 h under an average temperature of 30 °C. The DHS reactor reached an actual HRT of 19.0 min, indicating good contact efficiency between wastewater and retained sludge. The DHS reactor retained dense sludge at 15.3-26.4 g VSS/L based on the sponge media volume. The sludge activity in terms of specific oxygen uptake rate was good. Excess sludge was produced as 0.051 g TSS/g COD removed (0.11 g TSS/g BOD removed), and a good SVI of 28 mL/g was observed. The sufficient performance was attributed to dense sludge with high activity, regardless of the low-strength wastewater. Overall, the DHS was advantageous owing to its simple operation, lack of operational problems, and low power consumption.
- Published
- 2014
- Full Text
- View/download PDF
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