研究者データベース
利谷 翔平RIYA Shoheiリヤ シヨウヘイ
| ■所属部署名 | 工学研究院 応用化学部門 | |||
| ■職名 | 准教授 | |||
Last Updated :2025/01/22
業績情報
氏名・連絡先
氏名
リヤ シヨウヘイ, 利谷 翔平, RIYA Shohei
主たる所属・職名
工学研究院 応用化学部門, 准教授
その他の所属
経歴
- -
東京農工大学大学院工学研究院 助教
自 2014年04月01日 - -
日本学術振興会特別研究員(PD)
自 2013年04月01日, 至 2014年03月31日 - -
日本学術振興会特別研究員(DC2)
自 2012年04月01日, 至 2013年03月31日
学歴
- 東京農工大学
工学研究科
応用化学
至 2013年03月, 修了, 博士後期 - 東京農工大学
工学研究科
応用化学
至 2010年03月, 修了, 博士前期 - 東京農工大学
工学部
化学システム工学科
至 2008年03月, 卒業 - 高知工業高専
至 2006年03月, 卒業
教育・研究活動状況
- 廃棄物をメタン発酵や炭化などによりエネルギ―や肥料へと変換する技術の開発や、肥料を施肥した土壌における水質や温室効果ガスの生成機構の解明・制御の研究を通じて、環境にやさしい廃棄物の資源循環に貢献します。
科学研究費助成事業
- 基盤研究(C)
メタンとアンモニアを回収するためのバイオ炭添加乾式メタン発酵の基礎検討
自 2023年, 至 2025年 - 若手研究
炭化物と生物膜を利用した養豚排水からの栄養塩回収と肥料的価値
自 2020年, 至 2022年 - 国際共同研究加速基金（国際共同研究強化(B)）
節水イネ栽培の環境影響：温室効果ガスの放出、重金属類の蓄積および栄養塩の流出
自 2020年, 至 2020年 - 国際共同研究加速基金（国際共同研究強化(B)）
節水イネ栽培の環境影響：温室効果ガスの放出、重金属類の蓄積および栄養塩の流出
自 2019年, 至 2019年 - 国際共同研究加速基金（国際共同研究強化(B)）
節水イネ栽培の環境影響：温室効果ガスの放出、重金属類の蓄積および栄養塩の流出
自 2018年, 至 2018年 - 基盤研究(C)
N2O同位体アナライザを用いた発酵残渣の品質と土壌のN2O生成反応との関係解明
自 2017年, 至 2019年 - 若手研究(B)
15N2ガス希釈法による湿地生態系における脱窒速度の評価
自 2014年, 至 2016年
論文
- Microaerophilic Activated Sludge System for Ammonia Retention toward Recovery from High-Strength Nitrogenous Wastewater: Performance and Microbial Communities
Tsukamoto, Hiroki; Phan, Hop V.; Suenaga, Toshikazu; Yasuda, Shohei; Kuroiwa, Megumi; Riya, Shohei; Ogata, Atsushi; Hori, Tomoyuki; Terada, Akihiko
ENVIRONMENTAL SCIENCE & TECHNOLOGY
AMER CHEMICAL SOC
A transition to ammonia recovery from wastewater has started; however, a technology for sustainable nitrogen retention in the form of ammonia and organic carbon removal is still in development. This study validated a microaerophilic activated sludge (MAS) system to efficiently retain ammonia from high-strength nitrogenous wastewater. The MAS is based on conventional activated sludge (CAS) with aerobic and settling compartments. Low dissolved oxygen (DO) concentrations (< 0.2 mg/L) and short solids retention times (SRTs) (< 5 days) eliminated nitrifying bacteria. The two parallel MASs were successfully operated for 300 days and had ammonia retention of 101.7 +/- 24.9% and organic carbon removal of 85.5 +/- 8.9%. The MASs mitigated N2O emissions with an emission factor of < 0.23%, much lower than the default value of CAS (1.6%). A short-term step-change test demonstrated that N2O indicated the initiation of nitrification and the completion of denitrification in the MAS. The parallel MASs had comparable microbial diversity, promoting organic carbon oxidation while inhibiting ammonia-oxidizing microorganisms (AOM(s)), as revealed by 16S rRNA gene amplicon sequencing, the quantitative polymerase chain reaction of functional genes, and fluorescence in situ hybridization of ss-proteobacteria AOB. The microbial analyses also uncovered that filamentous bacteria were positively correlated with effluent turbidity. Together, controlling DO and SRT achieved organic carbon removal and successful ammonia retention, mainly by suppressing AOM activity. This process represents a new nitrogen management paradigm.
2023年09月07日, 研究論文（学術雑誌）, 共同, 57, 37, 0013-936X, DOI(公開)(r-map), 13874, 13886 - The effect and mechanism of polyethylene terephthalate microplastics on anaerobic co-digestion of sewage sludge and food waste
Wang, Pan; Guo, Yuwen; Yu, Miao; Riya, Shohei; Zheng, Yi; Ren, Lianhai
BIOCHEMICAL ENGINEERING JOURNAL
ELSEVIER
This research investigated the impact of polyethylene terephthalate (PET) microplastics on the anaerobic co-digestion of sewage sludge and food waste. The performance of anaerobic digester was investigated with different particle sizes (30 & mu;m and 250 & mu;m) PET at concentrations of 0, 0.45, 1.35, and 2.70 mg/g total solid (TS). Results suggested that the CH4 production at 2.70 mg/g TS level decreased by 21.63% (30 & mu;m) and 15.87% (250 & mu;m) compared with the control group, respectively. PET microplastics exerted negative influence through leaching toxic diisobutyl phthalate (DIBP) and dibutyl phthalate (DBP). Microbial community analysis and redundancy analysis showed that DIBP and DBP reduced the abundances of key hydrolysis bacteria (Bacteroides vadin HA17) and acidification bacteria (Clostridium and Sphaerochaeta). Structural equation model analysis showed that DBP and DIBP were the key factors that reduced the methane production, and they had stronger impact on daily methane production in the 30 & mu;m group compared with the 250 & mu;m group.
2023年09月, 研究論文（学術雑誌）, 共同, 198, 1369-703X, DOI(公開)(r-map) - Evaluation of Pollution Level, Spatial Distribution, and Ecological Effects of Antimony in Soils of Mining Areas: A Review
Zhao, Shuting; Shi, Taoran; Terada, Akihiko; Riya, Shohei
INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH
MDPI
The first global-scale assessment of Sb contamination in soil that was related to mining/smelting activities was conducted based on 91 articles that were published between 1989 and 2021. The geographical variation, the pollution level, the speciation, the influencing factors, and the environmental effects of Sb that were associated with mining/smelting-affected soils were analyzed. The high Sb values mainly occurred in developed (Poland, Italy, Spain, Portugal, New Zealand, Australia) and developing (China, Algeria, Slovakia) countries. Sb concentrations of polluted soil from mining areas that were reported in most countries significantly exceeded the maximum permissible limit that is recommended by WHO, except in Turkey and Macedonia. The soil Sb concentrations decreased in the order of Oceania (29,151 mg/kg) > North Africa (13,022 mg/kg) > Asia (1527 mg/kg) > Europe (858 mg/kg) > South America (37.4 mg/kg). The existing extraction methods for Sb speciation have been classified according to the extractant, however, further research is needed in the standardization of these extraction methods. Modern analytical and characterization technologies, e.g., X-ray absorption spectroscopy, are effective at characterizing chemical speciation. Conditional inference tree (CIT) analysis has shown that the clay content was the major factor that influenced the soil Sb concentration. Non-carcinogenic risks to the public from soil Sb pollution were within the acceptable levels in most regions. An Sb smelter site at the Endeavour Inlet in New Zealand, an abandoned open-pit Sb mine in Djebel Hamimat, Algeria, an old Sb-mining area in Tuscany, Italy, and Hillgrove mine in Australia were selected as the priority control areas. Cynodon dactylon, Boehmeria, Pteris vittata, and Amaranthus paniculatus were found to be potential Sb accumulators. All of the values of bioaccumulation factors for the crops were less than one. However, ingestion of Sb through crop consumption posed potential non-carcinogenic health risks, which should not be neglected. The soil variables (pH, Eh, total sulfur, carbon nitrogen ratio, total organic carbon, and sulfate), the total Sb and the bioavailable Sb, and heavy metal(loid)s (As, Pb, and Fe) were the major parameters affecting the microbial community compositions.
2023年01月, 研究論文（学術雑誌）, 共同, 20, 1, DOI(公開)(r-map) - Trade-off evaluation using carbon dioxide equivalent and hazard index of a paddy soil with application of organic liquid fertilizer
Riya, Shohei; Imano, Ryo; LI, Jining; Sun, Huifeng; Zhou, Sheng; Hosomi, Masaaki
PEDOSPHERE
SCIENCE PRESS
2022年12月, 研究論文（学術雑誌）, 共同, 32, 6, 1002-0160, DOI(公開)(r-map), 928, 932 - Exploring the Functions of Efficient Canonical Denitrifying Bacteria as N2O Sinks: Implications from N-15 Tracer and Transcriptome Analyses
Oba, Kohei; Suenaga, Toshikazu; Kuroiwa, Megumi; Riya, Shohei; Terada, Akihiko
ENVIRONMENTAL SCIENCE & TECHNOLOGY
AMER CHEMICAL SOC
In denitrifying reactors, canonical complete denitrifying bacteria reduce nitrate (NO3-) to nitrogen via N2O. However, they can also produce N2O under certain conditions. We used a N-15 tracer method, in which N-15-labeled NO3-/nitrite (NO2-) and nonlabeled N2O were simultaneously supplied with organic electron donors to five canonical complete denitrifying bacteria affiliated with either Clade I or Clade II nosZ. We calculated their NO3-, NO2-, and N2O consumption rates. The Clade II nosZ bacterium Azospira sp. strain I13 had the highest N2O consumption rate (3.47 +/- 0.07 fmol/cell/h) and the second lowest NO3- consumption rate (0.20 +/- 0.03 fmol/cell/h); hence, it is a N2O sink. A change from peptone- to acetate/citrate-based organic electron donors increased the NO3- consumption rate by 4.8 fold but barely affected the N2O consumption rate. Electron flow was directed to N2O rather than NO3- in Azospira sp. strain I13 and Az. oryzae strain PS only exerting a N2O sink but to NO3- in the Clade I nosZ N2O-reducing bacteria Pseudomonas stutzeri strain JCM 5965 and Alicycliphilus denitrificans strain I51. Transcriptome analyses revealed that the genotype could not fully describe the phenotype. The results show that N2O production and consumption differ among canonical denitrifying bacteria and will be useful for developing N2O mitigation strategies.
2022年08月16日, 研究論文（学術雑誌）, 共同, 56, 16, 0013-936X, DOI(公開)(r-map), 11694, 11706 - Exploring the Functions of Efficient Canonical Denitrifying Bacteria as N2O Sinks: Implications from N-15 Tracer and Transcriptome Analyses
Oba, Kohei; Suenaga, Toshikazu; Kuroiwa, Megumi; Riya, Shohei; Terada, Akihiko
ENVIRONMENTAL SCIENCE & TECHNOLOGY
AMER CHEMICAL SOC
In denitrifying reactors, canonical complete deni-trifying bacteria reduce nitrate (NO3-) to nitrogen via N2O. However, they can also produce N2O under certain conditions. We used a 15N tracer method, in which 15N-labeled NO3-/nitrite (NO2-) and nonlabeled N2O were simultaneously supplied with organic electron donors to five canonical complete denitrifying bacteria affiliated with either Clade I or Clade II nosZ. We calculated their NO3-, NO2-, and N2O consumption rates. The Clade II nosZ bacterium Azospira sp. strain I13 had the highest N2O consumption rate (3.47 +/- 0.07 fmol/cell/h) and the second lowest NO3- consumption rate (0.20 +/- 0.03 fmol/cell/h); hence, it is a N2O sink. A change from peptone-to acetate/citrate-based organic electron donors increased the NO3- consumption rate by 4.8 fold but barely affected the N2O consumption rate. Electron flow was directed to N2O rather than NO3- in Azospira sp. strain I13 and Az. oryzae strain PS only exerting a N2O sink but to NO3- in the Clade I nosZ N2O-reducing bacteria Pseudomonas stutzeri strain JCM 5965 and Alicycliphilus denitrificans strain I51. Transcriptome analyses revealed that the genotype could not fully describe the phenotype. The results show that N2O production and consumption differ among canonical denitrifying bacteria and will be useful for developing N2O mitigation strategies.
2022年08月02日, 研究論文（学術雑誌）, 共同, 0013-936X, DOI(公開)(r-map) - Significance of soil moisture on temperature dependence of Hg emission
Zhao, S.; Terada, A.; Nakamura, K.; Nakashima, M.; Komai, T.; Riya, S.; Hosomi, M.; Hou, H.
JOURNAL OF ENVIRONMENTAL MANAGEMENT
ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD
Soil moisture is a key factor for mercury (Hg) emission from soil. Despite its significance for Hg emissions, the effect of soil moisture on Hg flux and fractions has not been thoroughly investigated. The objective of this study was to elucidate the influences of soil moisture and temperature on Hg fluxes from soils and Hg fractions. A kinetic study was performed to measure Hg emission fluxes of six soil samples under different temperature (T) (15 degrees C, 20 degrees C, 25 degrees C, 30 degrees C, and 35 degrees C) and moisture conditions (0%, 10%, and 20% added water). The results showed that the Hg fluxes increased with increases in T and soil moisture. A linear correlation was found between ln (Hg emission flux) and 1/T for the six soil samples at different moisture contents (R-2 = 0.73-0.99). The range of activation energy (Ea) values was 25.31-57.86 kJ/mol. The Hg fractions in soils of different moisture content were determined by a sequential extraction method. The results demonstrated that soil moisture affected the Hg fractions in soils. The Ea values had different relationships with soil moisture in different soils. There were correlations between Ea and the elemental and mercuric sulfide fractions for air-dried soils. However, for moist soils, Ea was negatively correlated with the water-soluble and acid-soluble fractions. Collectively, the combination of the Hg emission kinetics and Hg fraction measurement of different moist soils indicated that Hg emission was affected by both total Hg concentration and Hg fractions.
2022年03月, 研究論文（学術雑誌）, 共同, 305, 0301-4797, DOI(公開)(r-map) - Nitrous oxide-sink capability of denitrifying bacteria impacted by nitrite and pH
Zhou, Yiwen; Zhao, Shuting; Suenaga, Toshikazu; Kuroiwa, Megumi; Riya, Shohei; Terada, Akihiko
CHEMICAL ENGINEERING JOURNAL
ELSEVIER SCIENCE SA
Nitrous oxide (N2O) is a highly potent greenhouse gas and ozone-depleting substance, produced and consumed during denitrification. Evaluation of the N2O production and consumption activities of complete denitrifying bacteria is essential for understanding their capacity to act as N2O sinks in engineered systems for cost-effective nitrogen removal via nitrite (NO2-). However, the physiologies of these N2O-reducing bacteria (N2ORB) are poorly understood. This study aimed to evaluate the physiologies of two N2ORB, Azospira sp. strain I13 and Alicycliphilus denitrificans strain I51. A N-15 tracer method was applied to determine N2O production and consumption activities in the co-presence of NO2- and N2O. Both N2ORB displayed a higher N2O consumption rate (RN2O by Azospira sp. strain I13 and Alicycliphilus denitrificans strain I51, 23.85 and 7.60 mu mol-N mg -biomass - 1h(-1), respectively) than N2O production rate (PN2O, 5.88 and 1.32 mu mol-N mg-biomass-1h(-1),respectively) at an initial NO2- concentration of 2.14 mmol-N L-1 with exogenous addition of N2O, indicating that these N2ORB acted as N2O sinks. On increasing the NO2- concentration from 0.36 to 7.14 mmol-N L-1, the net N2O consumption rate R-O_N2O (=R-N2O - P-N2O) decreased for both N2ORB; the magnitude of the decrease was greater for Azospira sp. strain I13 than for Alicycliphilus denitrificans strain I51. The formation of free nitrous acid (FNA) from NO2- in acidic conditions noticeably affected the N2O sink activities of the N2ORB. A higher FNA concentration decreased R-O_N2O for both N2ORB, creating the risk of N2O emission at pH 6 and high NO2- con centration.Our results show the ranges of pH and NO2- concentration where Azospira sp. strain I13 is promising for use as an N2O sink in shortcut nitrogen removal via NO2- .
2022年01月15日, 研究論文（学術雑誌）, 共同, 428, 1385-8947, DOI(公開)(r-map) - Temperature and oxygen level determine N2O respiration activities of heterotrophic N2O-reducing bacteria: Biokinetic study
Zhou, Yiwen; Suenaga, Toshikazu; Qi, Chuang; Riya, Shohei; Hosomi, Masaaki; Terada, Akihiko
BIOTECHNOLOGY AND BIOENGINEERING
WILEY
Nitrous oxide (N2O), a potent greenhouse gas, is reduced to N-2 gas by N2O-reducing bacteria (N2ORB), a process which represents an N2O sink in natural and engineered ecosystems. The N2O sink activity by N2ORB depends on temperature and O-2 exposure, yet the specifics are not yet understood. This study explores the effects of temperature and oxygen exposure on biokinetics of pure culture N2ORB. Four N2ORB, representing either clade I type nosZ (Pseudomonas stutzeri JCM5965 and Paracoccus denitrificans NBRC102528) or clade II type nosZ (Azospira sp. strains I09 and I13), were individually tested. The higher activation energy for N2O by Azospira sp. strain I13 (114.0 +/- 22.6 kJ mol(-1)) compared with the other tested N2ORB (38.3-60.1 kJ mol(-1)) indicates that N2ORB can adapt to different temperatures. The O-2 inhibition constants (K-I) of Azospira sp. strain I09 and Ps. stutzeri JCM5965 increased from 0.06 +/- 0.05 and 0.05 +/- 0.02 mu mol L-1 to 0.92 +/- 0.24 and 0.84 +/- 0.31 mu mol L-1, respectively, as the temperature increased from 15 degrees C to 35 degrees C, while that of Azospira sp. strain I13 was temperature-independent (p = 0.106). Within the range of temperatures examined, Azospira sp. strain I13 had a faster recovery after O-2 exposure compared with Azospira sp. strain I09 and Ps. stutzeri JCM5965 (p < 0.05). These results suggest that temperature and O-2 exposure result in the growth of ecophysiologically distinct N2ORB as N2O sinks. This knowledge can help develop a suitable N2O mitigation strategy according to the physiologies of the predominant N2ORB.
2021年03月, 研究論文（学術雑誌）, 共同, 118, 3, 0006-3592, DOI(公開)(r-map), 1330, 1341 - 乾式メタン発酵および多収米栽培を導入した養豚における環境負荷の評価
利谷翔平・周勝・細見正明
環境科学会誌
2021年01月31日, 研究論文（学術雑誌）, 共同, 34, DOI(公開)(r-map), 27, 39 - Nonlinear response of methane release to increased trophic state levels coupled with microbial processes in shallow lakes
Zhou, Yiwen; Song, Kang; Han, Ruiming; Riya, Shohei; Xu, Xiaoguang; Yeerken, Senbati; Geng, Shixiong; Ma, You; Terada, Akihiko
ENVIRONMENTAL POLLUTION
ELSEVIER SCI LTD
Shallow lakes are a crucial source of methane (CH4), a potent greenhouse gas, to the atmosphere. However, large uncertainties still exist regarding the response of CH4 emissions to the increasing trophic levels of lakes as well as the underlying mechanisms. Here, we investigate the CH4 emission flux from lakes with different trophic states in the middle and lower reaches of the Yangtze River basin, China to evaluate the effect of the trophic lake index (TLI) on CH4 emissions. The mean CH4 emission fluxes from mesotrophic, eutrophic, middle-eutrophic, and hyper-eutrophic lakes were 0.1, 4.4, 12.0, and 130.4 mg m(-2)h(-1), respectively. Thus, the CH4 emission flux ranged widely and was positively correlated with the degree of eutrophication. The relative abundance of methanogens with respect to the total population for the mesotrophic, eutrophic, mid-eutrophic, and hyper-eutrophic states was 0.03%, 0.35%, 0.94%, and 1.17%, respectively. The biogeographic-scale pattern of lakes classified as each of these four trophic states indicated that CH4 emissions could be well-predicted by the NH4+-N concentration in the water column, as both NH4+-N and CH4 were produced during mineralisation of labile organic matter in lake sediment. In addition, the shift from clear to turbid water, which is an unhealthy evolution for lakes, was associated with a nonlinear increase in the CH4 emissions from the studied lakes. In particular, the hypereutrophic lakes functioned as CH4 emission hotspots. Our findings highlight that nutrient levels, as a potential facilitator of CH4 emissions, should be considered in future research to accurately evaluate the greenhouse gas emissions from shallow lakes. (C) 2020 Elsevier Ltd. All rights reserved.
2020年10月, 研究論文（学術雑誌）, 共同, 265, 0269-7491, DOI(公開)(r-map) - Exploration and enrichment of methane-oxidizing bacteria derived from a rice paddy field emitting highly concentrated methane
Yasuda, Shohei; Toyoda, Risako; Agrawal, Shelesh; Suenaga, Toshikazu; Riya, Shohei; Hori, Tomoyuki; Lackner, Susanne; Hosomi, Masaaki; Terada, Akihiko
JOURNAL OF BIOSCIENCE AND BIOENGINEERING
SOC BIOSCIENCE BIOENGINEERING JAPAN
Methane-oxidizing bacteria (MOB) possess the metabolic potential to assimilate the highly potent greenhouse gas, CH4, and can also synthesize valuable products. Depending on their distinct and fastidious metabolic pathways, MOB are mainly divided into Type I and Type II; the latter are known as producers of polyhydroxyalkanoate (PHA). Despite the metabolic potential of MOB to synthesize PHA, the ecophysiology of MOB, especially under high CH4 flux conditions, is yet to be understood. Therefore, in this study, a rice paddy soil receiving a high CH4 flux from underground was used as an inoculum to enrich MOB using fed-batch operation, then the enriched Type II MOB were characterized. The transitions in the microbial community composition and CH4 oxidation rates were monitored by 16S rRNA gene amplicon sequencing and degree of CH4 consumption. With increasing incubation time, the initially dominant Methylomonas sp., affiliated with Type I MOB, was gradually replaced with Methylocystis sp., Type II MOB, resulting in a maximum CH4 oxidation rate of 1.40 g-CH4/g-biomass/day. The quantification of functional genes encoding methane monooxygenase, pmoA and PHA synthase, phaC, by quantitative PCR revealed concomitant increases in accordance with the Type II MOB enrichment. These increases in the functional genes underscore the significance of Type II MOB to mitigate greenhouse gas emission and produce PHA. (C) 2020, The Society for Biotechnology, Japan. All rights reserved.
2020年09月, 研究論文（学術雑誌）, 共同, 130, 3, 1389-1723, DOI(公開)(r-map), 311, 318 - Eco-compatible biochar mitigates volatile fatty acids stress in high load thermophilic solid-state anaerobic reactors treating agricultural waste
Meng, Lingyu; Xie, Li; Suenaga, Toshikazu; Riya, Shohei; Terada, Akihiko; Hosomi, Masaaki
BIORESOURCE TECHNOLOGY
ELSEVIER SCI LTD
A high concentration of accumulated volatile fatty acids (VFAs) is one of the most important factors resulting in reactor failure during solid-state anaerobic digestion. In this study, the feedstock-to-inoculum (F/I) ratio (0.5, 2, 3, 4 and 6) and the recovery method after failure (biochar addition or inoculum addition) were investigated in batch solid-state anaerobic digestion fed with rice straw and pig urine. An F/I ratio of 3 was the threshold for stable operation, while the reactors failed at F/I ratios of 4 and 6 because of high accumulated VFAs concentrations (above 30 g HAc/kg). Biochar addition (10% or 20% (wet weight) of the mixture) was as effective as inoculum addition (by adjusting the F/I ratio to 2 or 3) in promoting VFAs degradation in failed reactors within a short period (< 1 day). The buffering capacity of biochar was important in promoting VFAs degradation.
2020年08月, 研究論文（学術雑誌）, 共同, 309, 0960-8524, DOI(公開)(r-map) - Reducing geogenic arsenic leaching from excavated sedimentary soil using zero-valent iron amendment followed by dry magnetic separation: A case study
Li, Jining; Yoshi, Shunsuke; Hashimoto, Yohey; Wang, Lei; Wang, Fenghe; Riya, Shohei; Terada, Akihiko; Hosomi, Masaaki
SCIENCE OF THE TOTAL ENVIRONMENT
ELSEVIER
Although the deep-layer sedimentary soils excavated from construction sites contain low level of geogenic arsenic (As), remediation is necessary when the As leachability exceeds the environmental standard (10 mu g/L) in Japan. In this study, the zero-valent iron (ZVI) amendment followed by dry magnetic separation (ZVI-DMS) was implemented for the treatment of a geogenic As-contaminated alkaline sedimentary soil (pH 8.9; 7.5 mg/kg of total As; 0.33 mg/kg of water-extractable As). This technology involves pH adjustment (adding H2SO4), ZVI addition, water content reduction (adding water adsorbent CaSO4 center dot 0.5H(2)O), and dry magnetic separation. The short-term and long-term As leachability before and after treatment was compared using sequential water leaching tests (SWLT). The results illustrated that As could be removed from the bulk soil through the magnetic separation of As-ZVI complexes, although the amount was limited (about 2% of total As). Moreover, immobilization played a dominant role in suppressing As leaching. The H2SO4 addition decreased pH to a circumneutral range and thereby suppress As release. The CaSO4 center dot 0.5H(2)O addition also contributed to the pH decrease and reduced As leachability. Besides, CaSO4 center dot 0.5H(2)O-dissolution released Ca2+ that favored As adsorption, and enhanced dissolved organic carbon (DOC) coagulation that decelerated As dissolution. SWLT results indicated that As leachability from remediated soil satisfied the environmental standard (10 mu g/L) in both short-term and long-term perspective. However, the secular stability of treated soil deserves more attention due to the easy re-release of As caused by As-bearing framboidal pyrite oxidation. Additionally, during ZVI-DMS process, there is a need to scientifically decide the dosage of ZVI to avoid excessive addition. Our results demonstrated that ZVI-DMS technology could be a promising remediation strategy for geogenic As contaminated sedimentary soils/rocks. (C) 2020 Elsevier B.V. All rights reserved.
2020年07月01日, 研究論文（学術雑誌）, 共同, 724, 0048-9697, DOI(公開)(r-map) - Effect of water-saving irrigation on the N2O dynamics and the contribution of exogenous and endogenous nitrogen to N2O production in paddy soil using N-15 tracing
Zhou, Sheng; Sun, Huifeng; Bi, Junguo; Zhang, Jining; Riya, Shohei; Hosomi, Masaaki
SOIL & TILLAGE RESEARCH
ELSEVIER
Water-saving irrigation techniques can effectively mitigate methane emissions from rice fields but typically enhance nitrous oxide (N2O) emissions due to changes in soil moisture content. However, few studies have examined the effect of different water regimes on N2O production using different species of exogenous nitrogen (N) fertilizer application. Furthermore, the contributions of exogenous N fertilizer and endogenous N of soil for N2O productions have not been elucidated. Using a series of lysimeters, three types of water management were employed in rice cultivation in this study: conventional irrigation management (CIM), alternate wetting and drying (AWD), and dry cultivation management (DCM). Ammonium nitrate (NH4NO3) fertilizer was applied as base, tillering, and heading fertilizer, which was then separated into two groups labeled with N-15 stable isotope (> 99 %) at two different N positions: (NH4NO3)-N-15 and (NH4NO3)-N-15. Higher peaks of N2O flux were observed following drainage of floodwater for AWD and DCM treatments. In addition, (N2O)-N-15 fluxes were clearly separated into two different patterns between (NO3-)-N-15 and (NH4+)-N-15 fertilizer application. Application of (NO3-)-N-15 fertilizer rapidly released (N2O)-N-15 but the (N2O)-N-15 flux for (NH4+)-N-15 fertilizer application slowly increased with a hysteresis effect, suggesting denitrification was the main pathway for (N2O)-N-15 production in paddy soil with (NO3-)-N-15 fertilizer added in a flooded situation. Conversely, (NH4+)-N-15 may need to be converted into (NO3-)-N-15 through nitrification, then denitrified and finally released as (N2O)-N-15. Furthermore, N2O production was likely enhanced by nitrification-denitrification processes due to the water level alternating near (th)e ground surface for AWD treatment. Consequently, the total N2O emission over the rice growing period was the highest from the AWD soils, at 2.4 times that for CIM treatments. The high proportion of N2O-N derived from soil endogenous N sources (81 % of total N2O emission) in the AWD treatment indicates that the alternating wetting-drying of soil stimulated N2O production using endogenous N mineralized from soil organic matter. Furthermore, water management of paddy soil affected N uptake by rice plants. The total N uptake by rice plants was significantly higher for CIM than for AWD and DCM treatments.
2020年06月, 研究論文（学術雑誌）, 共同, 200, 0167-1987, DOI(公開)(r-map) - Role of leaves in methane emission from sacred lotus (nelumbo nucifera)
Riya, S.; Sun, H.; Furuhata, H.; Shimamura, M.; Nasu, H.; Imano, R.; Zhou, S.; Hosomi, M.
AQUATIC BOTANY
ELSEVIER
Sacred lotus (Nelumbo nucifera) is known to vent pressurized air in the leaf blade through stomata on the central plate of the leaf via the rhizome. This study measured diurnal CH4 emissions from lotus-cultivated in tanks during July and August 2016. CH4 emissions from the central plate of leaves of different age were also evaluated. Average daily CH4 fluxes of lotus-cultivated tanks were 23.1 +/- 5.6 and 11.4 +/- 6.0 mg C m(-2) h(-1) during July and August, respectively. Both the diurnal pattern of flow rate and the CH4 concentration of gas emitted from the central plate were similar to those of lotus and other wetland plants. However, the diurnal pattern of CH4 flux of younger leaves was dissimilar to that of tanks with cultivated lotus. Younger leaves exhibited a higher flow rate and greater concentration of CH4 than older leaves. This implies that pressurized air in older leaves is emitted through younger leaves, which contrasts with other plants that emit gas from older leaves or columns via pressurization.
2020年04月, 研究論文（学術雑誌）, 共同, 163, 0304-3770, DOI(公開)(r-map), 103203 - Enrichment, Isolation, and Characterization of High-Affinity N2O-Reducing Bacteria in a Gas-Permeable Membrane Reactor
Suenaga, Toshikazu; Hori, Tomoyuki; Riya, Shohei; Hosomi, Masaaki; Smets, Barth F.; Terada, Akihiko
ENVIRONMENTAL SCIENCE & TECHNOLOGY
AMER CHEMICAL SOC
The recent discovery of nitrous oxide (N2O)-reducing bacteria suggests a potential biological sink for the potent greenhouse gas N2O. For an application toward N2O mitigation, characterization of more isolates will be required. Here, we describe the successful enrichment and isolation of high-affinity N2O-reducing bacteria using a N2O-fed reactor (N2OFR). Two N(2)OFRs, where N2O was continuously and directly supplied as the sole electron acceptor to a biofilm grown on a gas-permeable membrane, were operated with acetate or a mixture of peptone-based organic substrates as an electron donor. In parallel, a NO3--fed reactor (NO3FR), filled with a nonwoven sheet substratum, was operated using the same inoculum. We hypothesized that supplying N2O vs NO3- would enhance the dominance of distinct N2O-reducing bacteria. Clade II type nosZ bacteria became rapidly enriched over Glade I type nosZ bacteria in the N(2)OFRs, whereas the opposite held in the NO3FR. High-throughput sequencing of 16S rRNA gene amplicons revealed the dominance of Rhodocyclaceae in the N(2)OFRs. Strains of the Azospira and Dechloromonas genera, canonical denitrifiers harboring Glade II type nosZ, were isolated with high frequency from the N(2)OFRs (132 out of 152 isolates). The isolates from the N2OFR demonstrated higher N2O uptake rates (V-max: 4.23 x 10(-3)-1.80 x 10(-2) pmol/h/cell) and lower N2O half-saturation coefficients (K-m,(N2O) : 1.55-2.10 mu M) than a Glade I type nosZ isolate from the NO3FR. Furthermore, the Glade II type nosZ isolates had higher specific growth rates on N2O than nitrite as an electron acceptor. Hence, continuously and exclusively supplying N2O in an N2OFR allows the enrichment and isolation of high-affinity N2O-reducing strains, which may be used as N2O sinks in bioaugmentation efforts.
2019年10月15日, 研究論文（学術雑誌）, 共同, 53, 20, 0013-936X, DOI(公開)(r-map), 12101, 12112 - Application of Biogas Digestate with Rice Straw Mitigates Nitrate Leaching Potential and Suppresses Root-Knot Nematode (Meloidogyne incognita)
Wang, Yuexi; Chikamatsu, Seiya; Gegen, Tuya; Sawada, Kozue; Toyota, Koki; Riya, Shohei; Hosomi, Masaaki
AGRONOMY-BASEL
MDPI
This study investigated the effects of biogas digestate application to soil with rice straw on nitrate leaching potential and nematicidal activity toward root-knot nematodes Meloidogyne incognita. The following seven treatments were set up: (i) control (CONT); (ii) chemical fertilizer (CF); (iii) wet biogas digestate derived from pig manure (WBD); (iv) and (v) dry biogas digestate derived from a mixture of pig manure and rice straw at an initial C/N ratio of 20 and 30 (DBD20 and DBD30); (vi) and (vii) DBD20 mixed with rice straw to adjust the C/N ratio to 16 (Mix1) and 30 (Mix2), respectively. The application rate of CF and digestates was adjusted to 200 mg N kg(-1) soil based on the inorganic ammonium nitrogen contents. Nitrate contents readily increased in all the treatments with incubation, except for Mix2, and those at day 90 were decreased with increasing initial labile C contents. Garden balsam was grown as a test plant for root-knot nematodes using the soils at day 90 and the results showed that the gall index was significantly lower in Mix2 and Mix1 than in CF. These results suggest that dry digestate mixed with rice straw might have potential for lower nitrate leaching and nematicidal properties.
2019年05月05日, 研究論文（学術雑誌）, 共同, 9, 5, DOI(公開)(r-map) - Comparison of leachate percolation and immersion using different inoculation strategies in thermophilic solid-state anaerobic digestion of pig urine and rice straw
Meng, Lingyu; Maruo, Koki; Xie, Li; Riya, Shohei; Terada, Akihiko; Hosomi, Masaaki
BIORESOURCE TECHNOLOGY
ELSEVIER SCI LTD
Heterogeneous distribution of substrate and microorganisms and low mass transfer limit methane production dramatically in solid-state anaerobic digestion (SS-AD). To overcome this challenge, this study determined the optimal inoculation strategy (complete premix/slurry application) for reusing solid digestate as inoculum and the optimal leachate circulation method (percolation/immersion) using batch digestion. Initially, percolation and immersion (1 h per 3 days) were compared and the result shows that immersing rice straw into leachate was superior to leachate percolation in methane production. Effect of the immersion period (24, 48 and 72 h) in each circulation cycle on methane production was then evaluated for each inoculation strategy. Methane production increased until the immersion period up to 24 h and then decreased, while the average cumulative methane yield with an immersion period of 24 h was (180 mL/g volatile solids). Slurry application with an immersion period 24 h is recommended as the optimum operating condition.
2019年04月, 研究論文（学術雑誌）, 共同, 277, 0960-8524, DOI(公開)(r-map), 216, 220 - Impact of turning waste on performance and energy balance in thermophilic solid-state anaerobic digestion of agricultural waste
Meng, Lingyu; Xie, Li; Riya, Shohei; Terada, Akihiko; Hosomi, Masaaki
WASTE MANAGEMENT
PERGAMON-ELSEVIER SCIENCE LTD
Mixing is an important operation in solid-state anaerobic digestion (SS-AD) to improve the mass transfer of the solid phase. This study proposed simple turning by loader in common garage-type digester without commonly used mixer or percolation system (simplified SS-AD). In simplified-SS-AD, turning is conducted in open condition. Thus, oxidation of anaerobic sludge during turning would influence digestion performance. Therefore, in this study, the effect of turning wastes by mixing during digestion on a simplified SS-AD fed with rice straw and pig urine was investigated. Four different mixing frequency levels- no mixing (MO) and mixing once a day (M-1/1), once every 3 days (M-1/3) and once a week (M-1/7)- were conducted. Methane yields of MO, M-1/3 and M-1/7 were comparable with each other. Methane yield and lag period of M-1/1 were approximately 61% and 155% of MO (351.2 mL/g VS and 4.7 days), respectively. Furthermore, the chemical oxygen demand (COD) of acetate accumulated in the digestate of M-1/1 was comparable to the difference in the COD of methane production between M-1/1 and the other treatments. Mixing every day also resulted in a higher oxidation-reduction potential and carbon dioxide content. These findings suggest that methanogenesis was inhibited in M-1/1 by frequent mixing in the atmosphere. Net energy analysis of SS-AD plant operation showed that MO can obtain the highest net energy gain, whereas net energy production of M-1/7 was reduced by rewarming after mixing. Therefore, no mixing is the most effective approach for the proposed simplified process. (C) 2019 Elsevier Ltd. All rights reserved.
2019年03月15日, 研究論文（学術雑誌）, 共同, 87, 0956-053X, DOI(公開)(r-map), 183, 191 - High-rate partial nitrification of semiconductor wastewater: Implications of online monitoring and microbial community structure
Song, Kang; Sawayanagi, Kaoru; Numano, Tetsurou; Taniichi, Yuya; Kikuchi, Takashi; Takeda, Tomoyuki; Kanou, Hisanao; Riya, Shohei; Hori, Tomoyuki; Hosomi, Masaaki; Terada, Akihiko
BIOCHEMICAL ENGINEERING JOURNAL
ELSEVIER SCIENCE BV
The aims of this study were to investigate the feasibility of partial nitrification (PN) in a sequencing batch reactor (SBR) fed with real wastewater discharged from the washing process at a semiconductor factory, to evaluate the efficacy of online control for nitrite buildup, and to examine the microbial community composition. To this end, online monitoring of NH4+ and NO3- concentrations in an SBR was implemented to track the extant activities of ammonia-oxidizing (AOB) and nitrite-oxidizing bacteria (NOB). The results showed that the rate of NH4+ oxidation by AOB increased during the first 20 days of the operation, and were maintained as high as a maximum volumetric rate of NH4+ removal of 2.17 kg-N/m(3)/day with an NH4+ removal efficiency of 94.1-99.8%. Successful nitrite buildup (> 99.9%) has been achieved after day 20 when AOB activity was 8.11-times higher than NOB activity. High-throughput sequencing of 16S rRNA genes manifested that the relative abundance of cluster 7 Nitrosomonas species in the family Nitrosomonadaceae increased from 0.2% to 50% over total bacteria. On the other hand, the relative abundance of Nitrospira spp. as the predominant NOB decreased from 1.0% to 0.05%, indicating NOB out-selection during SBR operations. A positive correlation was noted between the abundance of the dominant AOB and NH4+ oxidation rate, suggesting that a simple nitrifier community regulated high-rate PN.
2019年03月15日, 研究論文（学術雑誌）, 共同, 143, 1369-703X, DOI(公開)(r-map), 34, 40 - Removal and immobilization of heavy metals in contaminated soils by chlorination and thermal treatment on an industrial-scale
Li, Jining; Hashimoto, Yohey; Riya, Shohei; Terada, Akihiko; Hou, Hong; Shibagaki, Yuichi; Hosomi, Masaaki
CHEMICAL ENGINEERING JOURNAL
ELSEVIER SCIENCE SA
Heavy metals contaminated soils are a potential exposure hazard to the public. This study demonstrated the application of chlorination and thermal treatment for remediation of heavy metals-contaminated soils on a full-industrial scale. Five soil samples were treated at a soil remediation factory equipped with an internally-heated rotary kiln (length: 17 m; diameter: 4 m; rotating speed: 0.60 rpm). The target soil temperature was set at about 950 degrees C. During treatment, calcium chloride was added to facilitate chlorination. The chlorination and thermal treatments effectively removed Pb and Cd and led to the slight removal of Cu and Zn but was not effective for Cr and Ni. Chlorination and thermal treatment also significantly reduced the bioaccessibility of heavy metals in soils, particularly Pb and Cd. The results of sequential extraction revealed that thermal treatment generally decreased the carbonate (C2), Fe/Mn oxide (F3) and organic matter (O4) fractions but tended to increase the residual (R5) fractions of heavy metals, indicating that the chlorination and thermal treatment also favored the immobilization of heavy metals. Overall, the results of this study suggest that remediation of heavy metals-contaminated soils by chlorination and thermal treatment is technologically feasible and that there is great potential for practical application of this method.
2019年03月01日, 研究論文（学術雑誌）, 共同, 359, 1385-8947, DOI(公開)(r-map), 385, 392 - High-rate partial nitrification of semiconductor wastewater: Implications of online monitoring and microbial community structure
Kang Song, Kaoru Sawayanagi, Tetsurou Numano, Yuya Taniichi, Takashi Kikuchi, Tomoyuki Takeda, Hisanao Kanou, Shohei Riya, Tomoyuki Hori, Masaaki Hosomi, Akihiko Terada
Biochemical Engineering Journal
2018年12月12日, 共同, 143, DOI(公開)(r-map), 34, 40 - Immobilization of Azospira sp. strain I13 by gel entrapment for mitigation of N2O from biological wastewater treatment plants: Biokinetic characterization and modeling
T. Suenaga, R. Aoyagi, N. Sakamoto, S. Riya, H. Ohashi, M. Hosomi, H. Tokuyama, A. Terada
Journal of Bioscience and Bioengineering
2018年08月, 研究論文（学術雑誌）, 共同, 126, DOI(公開)(r-map), 213, 219 - Investigations of water-extractability of As in excavated urban soils using sequential leaching tests: Effect of testing parameters
J. Li, T. Kosugi, S. Riya, Y. Hashimoto, H. Hou, A. Terada, M. Hosomi
Journal of Environmental Management
2018年07月, 研究論文（学術雑誌）, 共同, 217, 297, 304 - Biokinetic Characterization and Activities of N2O-Reducing Bacteria in Response to Various Oxygen Levels
Suenaga, Toshikazu; Riya, Shohei; Hosomi, Masaaki; Terada, Akihiko
FRONTIERS IN MICROBIOLOGY
FRONTIERS MEDIA SA
Nitrous oxide (N2O)-reducing bacteria, which reduce N2O to nitrogen in the absence of oxygen, are phylogenetically spread throughout various taxa and have a potential role as N2O sinks in the environment. However, research on their physiological traits has been limited. In particular, their activities under microaerophilic and aerobic conditions, which severely inhibit N2O reduction, remain poorly understood. We used an O-2 and N2O micro-respirometric system to compare the N2O reduction kinetics of four strains, i.e., two strains of an Azospira sp., harboring Glade II type nosZ, and Pseudomonas stutzen and Paracoccus denitrificans, harboring Glade I type nosZ, in the presence and absence of oxygen. In the absence of oxygen, the highest N2O-reducing activity, V-m,V-N20, was 5.80 +/- 1.78 x 10(-3) pmol/h/cell of Azospira sp. I13, and the highest and lowest half-saturation constants were 34.8 +/- 10.2 mu M for Pa, denitirificans and 0.866 +/- 0.29 mu M for Azospira sp. I09. Only Azospira sp. I09 showed N2O-reducing activity under microaerophilic conditions at oxygen concentrations below 110 mu M, although the activity was low (10% of V-m,V-N2O). This trait is represented by the higher O-2 inhibition coefficient than those of the other strains. The activation rates of N2O reductase, which describe the resilience of the N2O reduction activity after O-2 exposure, differ for the two strains of Azospira sp. (0.319 +/- 0.028 h(-1) for strain I09 and 0.397 +/- 0.064 h(-1) for strain I13) and Ps. stutyen (0.200 +/- 0.013 h(-1)), suggesting that Azospira sp. has a potential for rapid recovery of N2O reduction and tolerance against O-2 inhibition. These physiological characteristics of Azospira sp. can be of promise for mitigation of N2O emission in industrial applications.
2018年04月10日, 研究論文（学術雑誌）, 共同, 9, 1664-302X, DOI(公開)(r-map) - Influence of feedstock-to-inoculum ratio on performance and microbial community succession during solid-state thermophilic anaerobic co-digestion of pig urine and rice straw
Meng, Lingyu; Xie, Li; Co Thi Kinh; Suenaga, Toshikazu; Hori, Tomoyuki; Riya, Shohei; Terada, Akihiko; Hosomi, Masaaki
BIORESOURCE TECHNOLOGY
ELSEVIER SCI LTD
This study investigated the effect of the feedstock-to-inoculum (F/I) ratio on performance of the solid-state anaerobic co-digestion of pig urine and rice straw inoculated with a solid digestate, and clarified the microbial community succession. A 44-day biochemical methane potential test at F/I ratios of 0.5, 1, 2 and 3 at 55 degrees C and a 35-day large-scale batch test at F/I ratios of 0.5 and 3 at 55 degrees C were conducted to investigate the effects of F/I ratio on anaerobic digestibility and analyze microbial community succession, respectively. The highest cumulative methane yield was 353.7m(3)/t VS in the large-scale batch test. Volatile fatty acids did not accumulate at any F/I ratios. The volatile solids reduction rate was highest at a F/I ratio of 0.5. Microbial community structures were similar between F/I ratios of 3 and 0.5, despite differences in digestion performance, suggesting that stable operation can be achieved at these ratios.
2018年03月, 研究論文（学術雑誌）, 共同, 252, 0960-8524, DOI(公開)(r-map), 127, 133 - The influence of the total solid content on the stability of dry-thermophilic anaerobic digestion of rice straw and pig manure
S. Riya, K. Suzuki, L. Meng, S. Zhou, A. Terada, M. Hosomi
Waste management
2018年03月, 研究論文（学術雑誌）, 共同, in press - Pollution potential leaching index as a tool to assess water leaching risk of arsenic in excavated urban soils
Li, Jining; Kosugi, Tomoya; Riya, Shohei; Hashimoto, Yohey; Hou, Hong; Terada, Akihiko; Hosomi, Masaaki
ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
ACADEMIC PRESS INC ELSEVIER SCIENCE
Leaching of hazardous trace elements from excavated urban soils during construction of cities has received considerable attention in recent years in Japan. A new concept, the pollution potential leaching index (PPLI), was applied to assess the risk of arsenic (As) leaching from excavated soils. Sequential leaching tests (SLT) with two liquid-to-solid (L/S) ratios (10 and 20 L kg(-1)) were conducted to determine the PPLI values, which represent the critical cumulative L/S ratios at which the average As concentrations in the cumulative leachates are reduced to critical values (10 or 5 mu g L-1). Two models (a logarithmic function model and an empirical two-site first-order leaching model) were compared to estimate the PPLI values. The fractionations of As before and after SLT were extracted according to a five-step sequential extraction procedure. Ten alkaline excavated soils were obtained from different construction projects in Japan. Although their total As contents were low (from 6.75 to 79.4 mg kg(-1)), the As leaching was not negligible. Different L/S ratios at each step of the SLT had little influence on the cumulative As release or PPLI values. Experimentally determined PPLI values were in agreement with those from model estimations. A five-step SLT with an L/S of 10 L kg(-1) at each step, combined with a logarithmic function fitting was suggested for the easy estimation of PPLI. Results of the sequential extraction procedure showed that large portions of more labile As fractions (non-specifically and specifically sorbed fractions) were removed during long-term leaching and so were small, but non-negligible, portions of strongly bound As fractions.
2018年01月, 研究論文（学術雑誌）, 共同, 147, 0147-6513, DOI(公開)(r-map), 72, 79 - Identification of hotspots for NO and N2O production and consumption in counter- and co-diffusion biofilms for simultaneous nitrification and denitrification
Co Thi Kinh; Riya, Shohei; Hosomi, Masaaki; Terada, Akihiko
BIORESOURCE TECHNOLOGY
ELSEVIER SCI LTD
A membrane-aerated biofilm reactor (MABR) provides a counter-current substrate diffusion geometry in which oxygen is supplied from a gas-permeable membrane on which a biofilm is grown. This study hypothesized that an MABR would mitigate NO and N2O emissions compared with those from a conventional biofilm reactor (CBR). Two laboratory-scale reactors, representing an MABR and CBR, were operated by feeding synthetic industrial wastewater. The surficial nitrogen removal rate for the MABR [4.51 +/- 0.52 g-N/(m(2) day)] was higher than that for the CBR [3.56 +/- 0.81 g-N/(m(2) day)] (p < 0.05). The abundance of beta-proteobacterial ammonia-oxidizing bacteria in the MABR biofilm aerobic zone was high. The NO and N2O concentrations at the biofilm-liquid interface in the MABR were 0.0066 +/- 0.0014 and 0.01 +/- 0.0009 mg-N/L, respectively, two and 28 times lower than those in the CBR. The NO and N2O production hotspots were closely located in the MABR aerobic zone.
2017年12月, 研究論文（学術雑誌）, 共同, 245, 0960-8524, DOI(公開)(r-map), 318, 324 - Counter-diffusion biofilms have lower N2O emissions than co-diffusion biofilms during simultaneous nitrification and denitrification: Insights from depth-profile analysis
Co Thi Kinh; Suenaga, Toshikazu; Hori, Tomoyuki; Riya, Shohei; Hosomi, Masaaki; Smets, Barth F.; Terada, Akihiko
WATER RESEARCH
PERGAMON-ELSEVIER SCIENCE LTD
The goal of this study was to investigate the effectiveness of a membrane-aerated biofilm reactor (MABR), a representative of counter-current substrate diffusion geometry, in mitigating nitrous oxide (N2O) emission. Two laboratory-scale reactors with the same dimensions but distinct biofilm geometries, i.e., a MABR and a conventional biofilm reactor (CBR) employing co-current substrate diffusion geometry, were operated to determine depth profiles of dissolved oxygen (DO), nitrous oxide (N2O), functional gene abundance and microbial community structure. Surficial nitrogen removal rate was slightly higher in the MABR (11.0 +/- 0.80 g-N/(m(2) day) than in the CBR (9.71 +/- 0.94 g-N/(m(2) day), while total organic carbon removal efficiencies were comparable (96.9 +/- 1.0% for MABR and 98.0 +/- 0.8% for CBR). In stark contrast, the dissolved N2O concentration in the MABR was two orders of magnitude lower (0.011 +/- 0.001 mg N2O-N/L) than that in the CBR (1.38 +/- 0.25 mg N2O-N/L), resulting in distinct N2O emission factors (0.0058 +/- 0.0005% in the MABR vs. 0.72 +/- 0.13% in the CBR). Analysis on local net N2O production and consumption rates unveiled that zones for N2O production and consumption were adjacent in the MABR biofilm. Real-time quantitative PCR indicated higher abundance of denitrifying genes, especially nitrous oxide reductase (nosZ) genes, in the MABR versus the CBR. Analyses of the microbial community composition via 16S rRNA gene amplicon sequencing revealed the abundant presence of the genera Thauera (31.2 +/- 11%), Rhizobium (10.9 +/- 6.6%), Stenotrophomonas (6.8 +/- 2.7%), Sphingobacteria (3.2 +/- 1.1%) and Brevundimonas (2.5 +/- 1.0%) as potential N2O-reducing bacteria in the MABR. (C) 2017 Elsevier Ltd. All rights reserved.
2017年11月, 研究論文（学術雑誌）, 共同, 124, 0043-1354, DOI(公開)(r-map), 363, 371 - Use of batch leaching tests to quantify arsenic release from excavated urban soils with relatively low levels of arsenic
Li, Jining; Kosugi, Tomoya; Riya, Shohei; Hashimoto, Yohey; Hou, Hong; Terada, Akihiko; Hosomi, Masaaki
JOURNAL OF SOILS AND SEDIMENTS
SPRINGER HEIDELBERG
Purpose In Japan, the excavated soils produced from constructions projects, which contain relatively low levels of arsenic (As), are considered as a potential concern if they could release significant amount of As to the environment. The aim of this study was to investigate the As leaching from excavated alkaline soils and, in particular, the influence of drying methods, pH of extracting solution, and consecutive washing on As leaching from these soils. Materials and methods Four excavated alkaline soils obtained from different construction sites in Tokyo, Japan, were used in this study. The soils were pretreated by three drying methods (air-dried, 40 degrees C-dried, and freeze-dried). Sequential extraction procedure was applied to partition As into five operationally defined chemical fractions. Batch leaching tests (initial pH-controlled leaching test and consecutive washing test) were conducted to investigate the As release under different leaching conditions. Results and discussion The As contents in the four soils were 9.22, 79.4, 6.75, and 11.7 mg kg(-1), respectively, and As was primarily associated with the residual phase. Arsenic leaching was strongly dependent on the extracting solution pH values. Strongly acidic extracting solution (pH 2) led to circumneutral leachates and limited As mobility, whereas the strong alkaline-extracting solution (pH 12) greatly enhanced the As release from these soils. The consecutive washing test results revealed a long-term release of As from these excavated soils. The pollution potential indices (PPIs) were successfully used to evaluate the pollution threat of As leaching from excavated soils. In addition, different drying methods resulted in variations in the short-and long-term release of As from these excavated soils. Conclusions The results revealed that the soil pretreatment and the leaching conditions should be considered if we want to use batch tests for the contamination assessment of excavated urban soils from construction projects. Different drying methods and single extraction may lead to misestimation of the As pollution level. High extraction efficiency with strong alkaline-extracting solution (pH 12) reveals that it could potentially be used to wash As from excavated alkaline soils.
2017年08月, 研究論文（学術雑誌）, 共同, 17, 8, 1439-0108, DOI(公開)(r-map), 2136, 2143 - 河川敷で発生する植物バイオマスの高温乾式メタン発酵特性
Riya, Shohei; Sawayanagi, Kaoru; Suzuki, Kazuhiro; Zhou, Sheng; Terada, Akihiko; Hosomi, Masaaki
KAGAKU KOGAKU RONBUNSHU
SOC CHEMICAL ENG JAPAN
The dry-thermophilic anaerobic digestibility of alternative biomasses to rice straw for pig manure treatment was evaluated. Seven grass and three woody biomasses were subjected to batch dry-thermophilic anaerobic digestion for methane (CH4) production. The CH4 production potential ranged from 109 +/- 8.1 to 347 +/- 62 m(3)/t-VS, with woody biomasses showing the lowest potential. This trend indicates a negative correlation between lignin content and CH4 production potential, suggesting that lignin content determines the CH4 production of the grass and woody biomasses. CH4 production quantities in Ibaraki Prefecture, where pig farming has been intensively practiced, were estimated to be respectively 31.3, 1.68, and 1.42 m(3)/y from rice straw, riverbed grasses, and wood (from riverbeds, parks, roads, and orchards). CH4 production yields from semi-batch dry-thermophilic anaerobic digestion of pig manure with cogon grass (Imperata cylindrica) and wood chips were respectively 251 +/- 44 and 157 +/- 9.4 m(3)/t-VS. These values were comparable to the CH4 production potential of these biomasses, suggesting their promise as alternatives to rice straw.
2017年07月, 研究論文（学術雑誌）, 共同, 43, 4, 0386-216X, DOI(公開)(r-map), 224, 230 - Nitrous oxide production and mRNA expression analysis of nitrifying and denitrifying bacterial genes under floodwater disappearance and fertilizer application
Riya, Shohei; Takeuchi, Yuki; Zhou, Sheng; Terada, Akihiko; Hosomi, Masaaki
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
SPRINGER HEIDELBERG
A pulse of nitrous oxide (N2O) emission has been observed following the disappearance of floodwater by drainage. However, its mechanism is not well understood. We conducted a column study to clarify the mechanism for N2O production during floodwater disappearance by using a microsensor and determining the bacterial gene expression. An increase in N2O flux was observed following floodwater disappearance after the addition of NH4+, with a corresponding increase in the concentrations of NO3- and dissolved N2O in the oxic and anoxic soil layers, respectively. The transcription level of the bacterial amoA mRNA did not change, while that of nirK mRNA increased sharply after an hour of floodwater disappearance. An additional anoxic soil slurry experiment demonstrated that the addition of NO3- induced the expression of nirK gene and caused a concomitant increase in N2O production. These findings suggest that NO3- production in the oxic layers is important as it provides a substrate and induces the synthesis of denitrification enzymes in the anoxic layer during N2O production.
2017年06月, 研究論文（学術雑誌）, 共同, 24, 18, 0944-1344, DOI(公開)(r-map), 15852, 15859 - Synthesis of CTAB intercalated graphene and its application for the adsorption of AR265 and AO7 dyes from water
Yusuf, Mohammed; Khan, Moonis Ali; Otero, Marta; Abdullah, E. C.; Hosomi, Masaaki; Terada, Akihiko; Riya, Shohei
JOURNAL OF COLLOID AND INTERFACE SCIENCE
ACADEMIC PRESS INC ELSEVIER SCIENCE
Environmental applications of graphene (GN) are limited by the occurrence of aggregation. Herein, graphene oxide (GO) was synthesized, reduced to GN by ascorbic acid, and intercalated with Cetyltrimethylammonium bromide (CTAB). GN-CTAB was characterized by Boehm's titration, N-2 adsorption/desorption, Fourier transform infrared spectroscopy, Raman spectroscopy, Fluorescence spectrophotometry, X-ray diffraction and Scanning electron microscopy. Then, GN-CTAB was used for the adsorptive removal of acid red 265 (AR265) and acid orange 7 (AO7) dyes from water both under batch and column operation. Under batch operation, the effect of pH, adsorbent dosage, initial dye concentration, contact time and temperature on dyes adsorption were assessed. Adsorption isotherms, kinetics, and thermodynamics were analyzed systematically. Regarding the fixed bed operation, the effect of both the bed height and flow rate were studied and experimental results fitted to the Thomas and BDST models. Then, the bed loss capacity along five adsorption-regeneration cycles was determined in order to further approach the practical application of GN-CTAB for wastewater treatment, namely for the removal of dyes. (C) 2017 Elsevier Inc. All rights reserved.
2017年05月, 研究論文（学術雑誌）, 共同, 493, 0021-9797, DOI(公開)(r-map), 51, 61 - Hybrid Nitrous Oxide Production from a Partial Nitrifying Bioreactor: Hydroxylamine Interactions with Nitrite
Terada, Akihiko; Sugawara, Sho; Hojo, Keisuke; Takeuchi, Yuki; Riya, Shohei; Harper, Willie F., Jr.; Yamamoto, Tomoko; Kuroiwa, Megumi; Isobe, Kazuo; Katsuyama, Chie; Suwa, Yuichi; Koba, Keisuke; Hosomi, Masaaki
ENVIRONMENTAL SCIENCE & TECHNOLOGY
AMER CHEMICAL SOC
The goal of this study was to elucidate the mechanisms of nitrous oxide (N2O) production from a bioreactor for partial nitrification (PN). Ammonia-oxidizing bacteria (AOB) enriched from a sequencing batch reactor (SBR) were subjected to N2O production pathway tests. The N2O pathway test was initiated by supplying an inorganic medium to ensure an initial NH44(+)-N concentration of 160 mg-N/L, followed by (NO2-)-N-15 (20 mg-N/L) and dual (NH2OH)-N-15 (each 17 mg-N/L) spikings to quantify isotopologs of gaseous N2O ((N2O)-N-44, (N2O)-N-45, and (N2O)-N-46). N2O production was boosted by (NH2OH)-N-15 spiking, causing exponential increases in mRNA transcription levels of AOB functional genes encoding hydroxylamine oxidoreductase (haoA), nitrite reductase (nirK), and nitric oxide reductase (norB) genes. Predominant production of (N2O)-N-45 among N2O isotopologs (46% of total produced N2O) indicated that coupling of (NH2OH)-N-15 with (NO2-)-N-14 produced N2O via N-nitrosation hybrid reaction as a predominant pathway. Abiotic hybrid N2O production was also observed in the absence of the AOB-enriched biomass, indicating multiple pathways for N2O production in a PN bioreactor. The additional N2O pathway test, where (NH4+)-N-15 was spiked into 400 mg-N/L of NO2- concentration, confirmed that the hybrid N2O production was a dominant pathway, accounting for approximately 51% of the total N2O production.
2017年03月, 研究論文（学術雑誌）, 共同, 51, 5, 0013-936X, DOI(公開)(r-map), 2748, 2756 - Free nitrous acid and pH determine the predominant ammonia-oxidizing bacteria and amount of N2O in a partial nitrifying reactor
Kinh, Co Thi; Ahn, Johwan; Suenaga, Toshikazu; Sittivorakulpong, Nakanya; Noophan, Pongsak; Hori, Tomoyuki; Riya, Shohei; Hosomi, Masaaki; Terada, Akihiko
APPLIED MICROBIOLOGY AND BIOTECHNOLOGY
SPRINGER
We investigated the effects of free ammonia (FA) and free nitrous acid (FNA) concentrations on the predominant ammonia-oxidizing bacteria (AOB) and the emission of nitrous oxide (N2O) in a lab-scale sequencing batch reactor for partial nitrification. The reactor was operated with stepwise increases in the NH4 (+) loading rate, which resulted in a maximum FA concentration of 29.3 mg-N/L at pH 8.3. Afterwards, FNA was increased by a gradual decrease of pH, reaching its maximum concentration of 4.1 mg-N/L at pH 6.3. Fluorescence in situ hybridization indicated that AOB remained predominant during the operation, achieving specific nitrification rates of 1.04 and 0.99 g-N/g-VSS/day at the highest accumulations of FA and FNA, respectively. These rates were in conjunction with partial nitrification efficiencies of > 84%. The N2O emission factor of oxidized NH4 (+) was 0.90% at pH 7.0, which was higher than those at pH 8.3 (0.11%) and 6.3 (0.12%), the pHs with the maximum FA and FNA concentrations, respectively. High-throughput sequencing of 16S ribosomal RNA genes showed that increases in FNA drastically changed the predominant AOB species, although increased FA produced no significant changes. This study demonstrates that the FNA concentration and pH are the main drivers that determine the predominant AOB species and N2O-emission in a partial nitrifying bioreactor.
2017年02月, 研究論文（学術雑誌）, 共同, 101, 4, 0175-7598, DOI(公開)(r-map), 1673, 1683 - Dodecyl Sulfate Chain Anchored Mesoporous Graphene: Synthesis and Application to Sequester Heavy Metal Ions from Aqueous Phase
M. Yusuf, M. A. Khan, E. C. Abdullah, M. Elfghi, M. Hosomi, A. Terada, S. Riya, A. Ahmad
Chemical Engineering Journal
2016年11月, 研究論文（学術雑誌）, 共同, 304, 431, 439 - Denitrification-dependent anammox activity in a permanently flooded fallow ravine paddy field
S. Zhou, S. Borjigin, S. Riya, M. Hosomi
Ecological Engineering
2016年10月, 研究論文（学術雑誌）, 共同, 95, 452, 456 - Potential for leaching of arsenic from excavated rock after different drying treatments
Jining Li, Tomoyuki Kosugi, Shohei Riya, Yohei Hashimoto, Hong Hou, Akihiko Terada, Masaaki Hosomi
Chemosphere
2016年07月, 研究論文（学術雑誌）, 共同, 154, 276, 282 - Variation of the microbial community in thermophilic anaerobic digestion of pig manure mixed with different ratios of rice straw
Sheng Zhou, Marcell Nikolausz, Jining Zhang, Shohei Riya, Akihiko Terada, Masaaki Hosomi
Journal of Bioscience and Bioengineering
2016年04月, 研究論文（学術雑誌）, 共同, 122, 3, 334, 340 - Influence of C/N Ratio on Performance and Microbial Community Structure of Dry-Thermophilic Anaerobic Co-Digestion of Swine Manure and Rice Straw
S. Riya, K. Suzuki, S. Zhou, A. Terada, M. Hosomi
Journal of Medical and Bioengineering
2016年02月, 研究論文（学術雑誌）, 共同, 5, 11, 14 - 有機性液肥を施用した水田における温室効果ガス放出およびその削減
利谷翔平, 上村美羽, 室井友里恵, 周 勝, 寺田昭彦, 細見正明
農業および園芸
2016年01月, 共同, 91, 211, 219 - Mass and energy balances of dry thermophilic anaerobic digestion treating swine manure mixed with rice straw
S. Zhou, J. Zhang, G. Zou, S. Riya, M. Hosomi
Biotechnology Research International
2015年12月, 研究論文（学術雑誌）, 共同, Article ID 895015 - Effects of aeration and internal recycle flow on nitrous oxide emissions from a Modified Ludzak–Ettinger process fed with glycerol
K. Song，T. Suenaga, W. F. Harper Jr., T. Hori, S. Riya, M. Hosomi, A. Terada
Environmental Science and Pollution Research
2015年12月, 研究論文（学術雑誌）, 共同, 22, 19562, 19570 - Novel abiotic reactions increase nitrous oxide production during partial nitrification: Modeling and experiments
W. F. Harper, Y. Takeuchi, S. Riya, M. Hosomi, A. Terada
Chemical Engineering Journal
2015年12月, 研究論文（学術雑誌）, 共同, 281, 1017, 1023 - Impact of carbon sources on nitrous oxide emission and microbial community structure in an anoxic/oxic activated sludge system
K. Song, W. F. Harper, T. Hori, S. Riya, M. Hosomi, A. Terada
Clean Technologies and Environment Policy
2015年12月, 研究論文（学術雑誌）, 共同, 17, 2375, 2385 - Effect of carbon sources on nitrous oxide emission in a Modified Ludzak Ettinger process
K. Song, S. Riya, M. Hosomi, A. Terada
Water Science and Technology
2015年12月, 研究論文（学術雑誌）, 共同, 72, 572, 578 - Effects of nitrogen loading rate on CH4 and N2O emissions during cultivation and fallow periods from forage rice fields fertilized with liquid cattle waste
S. Riya, S. Zhou, Y. Kobara, M. Sagehashi, A. Terada, M. Hosomi
Journal of Environmental Management
2015年09月, 研究論文（学術雑誌）, 共同, 161, 124, 130 - 水田土壌からの亜硝酸ガス（HONO）直接発生フラックスの測定および大気濃度への寄与評価
峰島知芳, 中根令以, 島田幸治郎, 利谷翔平, 佐藤啓市, 大山正幸, 寺田昭彦, 細見正明
大気環境学会誌
2015年08月, 研究論文（学術雑誌）, 共同, 50, 249, 256 - 回分式・連続式部分硝化型リアクターの亜硝酸酸化性能と硝化細菌のダイナミクス
澤柳薫、種部悠未、狩野久直、竹田有之、沼野哲朗、利谷翔平、細見正明、寺田昭彦
用水と廃水
2015年06月, 研究論文（学術雑誌）, 共同, 57, 6, 431, 440 - Influence of Nitrogen Loading and Plant Nitrogen Assimilation on Nitrogen Leaching and N2O Emission in Forage Rice Paddy Fields Fertilized with Liquid Cattle Waste
S. Riya, S. Zhou, Y. Kobara, M. Sagehashi, A. Terada, M. Hosomi
Environmental Science and Pollution Research
2015年04月, 研究論文（学術雑誌）, 共同, 22, 5762, 5771 - Mitigation of CH4 and N2O emissions from a forage rice field fertilized with aerated liquid fraction of cattle slurry by optimizing water management and topdressing
S. Riya, Y. Muroi, M. Kamimura, S. Zhou, A. Terada, Y. Kobara, M. Hosomi
Ecological Engineering
2014年12月, 研究論文（学術雑誌）, 共同, 75, 24, 32 - Mitigation of Greenhouse Gas Emissions by Water Management in a Forage Rice Paddy Field Supplemented with Dry-Thermophilic Anaerobic Digestion Residue
S. Riya, M. Katayama, E. Takahashi, S. Zhou, A. Terada, M. Hosomi
Water Air and Soil Pollution
2014年08月, 研究論文（学術雑誌）, 共同, 225 - 乾式メタン発酵と飼料イネによる資源循環型養豚排水処理
細見正明, 豊田剛己, 利谷翔平
畜産環境情報
2014年08月, 共同, 53, 1, 10 - The relationship between anammox and denitrification in the sediment of an inland river
S. Zhou, S. Borjigin, S. Riya, A. Terada, M. Hosomi
Science of the Total Environment
2014年06月, 研究論文（学術雑誌）, 共同, 490, 1029, 1036 - Abundance, transcription levels and phylogeny of bacteria capable of nitrous oxide reduction in a municipal wastewater treatment plant
K. Song, T. Suenaga, A. Hamamoto, K. Satou, S. Riya, M. Hosomi, A. Terada
Journal of Bioscience and Bioengineering
2014年04月, 研究論文（学術雑誌）, 共同, 118, 289, 297 - Short-Term Responses of Nitrous Oxide Emissions and Concentration Profiles to Fertilization and Irrigation in Greenhouse Vegetable Cultivation
S. Riya, J. Min, S. Zhou, W.M. Shi, M. Hosomi
Pedosphere
2012年12月, 研究論文（学術雑誌）, 共同, 22, 764, 775 - 畜産排水を高窒素負荷で施肥した飼料イネ水田における窒素除去の解明
利谷翔平, 周勝, 下ヶ橋雅樹, 寺田昭彦, 細見正明
化学工学論文集
2012年09月, 研究論文（学術雑誌）, 共同, 38, 290, 298 - In Situ Dissimilatory Nitrate Reduction to Ammonium in a Paddy Soil Fertilized with Liquid Cattle Waste
W. W. Lu, S. Riya, S. Zhou, M. Hosomi, H. L. Zhang, W. M. Shi
Pedosphere
2012年06月, 研究論文（学術雑誌）, 共同, 22, 314, 321 - Assessing nitrification and denitrification in a paddy soil with different water dynamics and applied liquid cattle waste using the 15N isotopic technique
S. Zhou, Y. Sakiyama, S. Riya, X. Song, A. Terada, M. Hosomi
Science of the Total Environment
2012年05月, 研究論文（学術雑誌）, 共同, 430, 93, 100 - CH4 and N2O emissions from different varieties of forage rice (Oryza sativa L.) treating liquid cattle waste
S. Riya, S. Zhou, Y. Watanabe, M. Sagehashi, A. Terada, M. Hosomi
Science of the Total Environment
2012年01月, 研究論文（学術雑誌）, 共同, 419, 178, 186 - Nitrogen transformations in paddy fields applied with high load liquid cattle waste
S. Zhou, H. Iino, S. Riya, M. Nishikawa, Y. Watanabe, M. Hosomi
Journal of Chemical Engineering of Japan
2011年10月, 研究論文（学術雑誌）, 共同, 44, 713, 719 - Effect of infiltration rate on nitrogen dynamics in paddy soil after high-load nitrogen application containing 15N tracer
S. Zhou, S. Sugawara, S. Riya, M. Sagehashi, K. Toyota, A. Terada, M. Hosomi
Ecological Engineering
2011年06月, 研究論文（学術雑誌）, 共同, 37, 685, 692 - 浸透流式飼料イネ人工湿地における温室効果ガスの直接および間接排出
利谷翔平, 周勝, 中島田豊, 寺田昭彦, 細見正明
化学工学論文集
2010年07月, 研究論文（学術雑誌）, 共同, 36, 229, 236
著書
- Anaerobic Digestion for Energy Recovery and Carbon Management
A. Kita, Y. Nakashimada, S. Riya
CRC Press
2021年01月01日 - Dry Anaerobic Digestion for Agricultural Waste Recycling
S. Riya, L. Meng, Y. Wang, C.G. Lee, S. Zhou, K. Toyota, M. Hosomi
IntechOpen
2020年02月19日 - 土のひみつ 食料・環境・生命
日本土壌肥料学会「土のひみつ」編集グループ 編
朝倉書店
2015年09月
研究発表、招待講演等
- 畜産廃棄物のメタン発酵と残渣の土壌利用におけるシステムの評価
化学工学会 第54回秋季大会
2023年09月11日, 口頭発表（招待・特別） - 水田土壌の乾燥・湿潤で発生するN2Oの生成反応の解明
化学工学会第86年会
2021年03月21日, 口頭発表（一般） - 乾式メタン発酵残渣の炭化におけるNガスの定性・定量
化学工学会第86年会
2021年03月21日, 口頭発表（一般） - 二酸化炭素等量と有害金属のハザード指数を用いた栽培法の評価
日本土壌肥料学会2020年度岡山大会
2020年09月08日, 口頭発表（一般） - Dry anaerobic digestion for recycling piggery waste and rice straw
Japan International Conference on Recycling and Waste Management (RMW-2020)
2020年07月02日, 口頭発表（招待・特別） - 同位体分析による落水後の水田におけるN2O生成反応の解明とバイオ炭によるN2O削減の検討
日本微生物生態学会第33回大会
2019年09月10日, ポスター発表 - 乾式メタン発酵による循環型豚ふん尿処理に関する研究
農業農村工学会平成30年度大会
2019年09月04日, 口頭発表（招待・特別） - 同位体分析による落水後の水田における亜酸化窒素生成反応の解明
⽇本⼟壌肥料学会2018年度神奈川⼤会
2018年09月29日, ポスター発表 - The influence of the total solid content on the stability of semi-batch dry-thermophilic anaerobic digestion of agricultural waste
2nd International Conference on Bioresource Technology for Bioenergy
2018年09月16日, ポスター発表 - Potential methane productivity by dry-thermophilic anaerobic co-digestion of grass and wood biomasses and pig manure in pig farming area in Japan
15th World Congress on Anaerobic Digestion
2017年10月17日, ポスター発表 - Environmental impact of forage rice cultivation by aerated cattle slurry
10th World Congress of Chemical Engineering
2017年10月, 口頭発表（一般） - 遺伝子発現解析と微小電極による水田の亜酸化窒素生成反応の推定
日本陸水学会第82回大会仙北市田沢湖大会
2017年09月, 口頭発表（一般） - 乾式メタン発酵残渣を施用したハス田における窒素挙動
日本陸水学会第82回大会仙北市田沢湖大会
2017年09月, 口頭発表（一般） - 酸素の存在が亜酸化窒素の還元活性に及ぼす影響：単離菌株による呼吸活性の動力学的評価
第51回日本水環境学会年会
2017年03月, 口頭発表（一般） - ハス（Nelumbo nucifera)の温室効果ガス放出
第51回日本水環境学会年会
2017年03月, 口頭発表（一般） - 乾式メタン発酵残渣を施用したハス田のレンコン収量及び水質への影響
第51回日本水環境学会年会
2017年03月, 口頭発表（一般） - 15N2ガス希釈法による脱窒速度の測定
第51回日本水環境学会年会
2017年03月, 口頭発表（一般） - 稲わらと豚尿の高温乾式メタン発酵における含水率の影響
第19回化学工学会学生発表会（小金井大会）
2017年03月, 口頭発表（一般） - 牛尿を用いた水稲栽培における 温室効果ガス放出、重金属蓄積の評価及び削減
第19回化学工学会学生発表会（小金井大会）
2017年03月, 口頭発表（一般） - ハスの温室効果ガス放出の評価および機構解明
第19回化学工学会学生発表会（小金井大会）
2017年03月, 口頭発表（一般） - Effect of Feedstock/Inoculum Ratio on Dry-Thermophilic Anaerobic Co-Digestion of Rice Straw and Pig Urine
1st International Conference on Bioresource Technology for Bioenergy, Bioproducts & Environmental Sustainability
2016年10月, 口頭発表（一般） - 15N2ガス希釈法による脱窒測定
日本土壌肥料学会2016年度東京大会
2016年09月, 口頭発表（一般） - Measurement of denitrification rate by 15N2 dilution method
5th International Ecosummit
2016年08月29日, ポスター発表 - Effect of total solid content on dry anaerobic digestion of rice straw and pig urine
Livestock Waste 2016
2016年08月10日, その他 - Effect of Feedstock/Inoculum Ratio on Dry-Thermophilic Anaerobic Co-Digestion of Rice Straw and Pig Urine
The Water and Environment Technology Conference 2016
2016年08月, 口頭発表（一般） - 稲わらと豚尿を用いた高温乾式メタン発酵における基質と菌体の関連性
化学工学会第81年会
2016年03月, 口頭発表（一般） - 発酵残渣を施肥したハス田における窒素挙動
第50回日本水環境学会年会
2016年03月, 口頭発表（一般） - 掘削したアルカリ性土壌からのヒ素溶出挙動
第50回日本水環境学会年会
2016年03月, 口頭発表（一般） - 集積培養により活性汚泥から獲得された亜酸化窒素還元細菌の生理活性
第50回日本水環境学会年会
2016年03月, 口頭発表（一般） - 部分硝化リアクターから放出される亜酸化窒素の生成メカニズム：非生物学的反応経路の関与
第50回日本水環境学会年会
2016年03月, 口頭発表（一般） - 淡水域に棲息するN2O同化を行うシアノバクテリアの探索
第50回日本水環境学会年会
2016年03月, 口頭発表（一般） - 細菌活性を抑制する酵素と細胞外ポリマーを分解する酵素を固定化させたポリマー材料によるバイオファウリング抑制
第50回日本水環境学会年会
2016年03月, 口頭発表（一般） - Characterization of dry-thermophilic anaerobic digestion of riverine plants
14th World Congress on Anaerobic Digestion
2015年11月01日, ポスター発表 - Effect of premixing and circulation of pig urine on dry-thermophilic Anaerobic Digestion
14th World Congress on Anaerobic Digestion
2015年11月01日, ポスター発表 - Development of novel pig farming system incorporating dry-thermophilic anaerobic digestion and forage rice cultivation
The 7th China-Japan Symposium on Chemical Engineering
2015年10月01日, 口頭発表（招待・特別） - Linking Drainage-Induced Nitrous Oxide Production and Functional Gene Expression of Nitrifier and Denitrifier in Flooded Soil
12th International Conference of the East and Southeast Asia Federation of Soil Science Societies
2015年09月01日, その他 - 稲わらを基質とする豚尿浸漬型回分乾式メタン発酵における基質/種汚泥比の影響
化学工学会第47回秋季大会
2015年09月01日, その他 - 稲わらを基質とする豚尿浸漬型回分乾式メタン発酵における基質/種汚泥比の影響
化学工学会第47回秋季大会
2015年09月, 口頭発表（一般） - 乾式メタン発酵残渣を施肥した多収米飼料イネ水田におけるメタン放出の削減
日本土壌肥料学会2015年度京都大会
2015年09月, その他 - ガス透過膜を用いた高活性な亜酸化窒素還元細菌の集積化と分離培養
化学工学会第80年会
2015年03月01日, その他 - 水田に棲息する脱窒性メタン酸化細菌の土壌空間分布とニッチ
化学工学会第80年会
2015年03月01日, ポスター発表 - 豚尿と稲わらの高温乾式メタン発酵における豚尿循環および基質混合方式の検討
化学工学会第80年会
2015年03月01日, その他 - ガス透過膜を用いた新規培養装置による高活性N2O還元細菌の集積化と分離培養
第49回日本水環境学会年会
2015年03月01日, その他 - 安定同位体プロービングと次世代シークエンサーの併用による亜酸化窒素還元細菌の高感度同定
第49回日本水環境学会年会
2015年03月01日, その他 - 亜硝酸濃度がアナモックス細菌および共存する脱窒細菌の活性に及ぼす影響評価
第49回日本水環境学会年会
2015年03月01日, ポスター発表 - 豚尿と稲わらの高温乾式メタン発酵における豚尿循環および基質混合方式の検討
第49回日本水環境学会年会
2015年03月01日, その他 - Influence of C/N ratio on performance and microbial community structure of dry-thermophilic anaerobic co-digestion of swine manure and rice straw
6th International Conference on Environmental Science and Development
2015年02月01日, その他 - Effect of carbon sources on nitrous oxide emission in a Modified Ludzak Ettinger process
9th IWA International Symposium on Waste Management Problems in Agro-Industries
2014年11月01日, その他 - Feasibility of pig manure treatment by dry-thermophilic anaerobic co-digestion with rice straw
9th IWA International Symposium on Waste Management Problems in Agro-Industries
2014年11月01日, その他 - 高温乾式メタン発酵および飼料イネ栽培を組み込んだ養豚システムのライフサイクルアセスメント
化学工学会第46回秋季大会
2014年09月01日, その他 - 落水後の水田土壌における 突発的亜酸化窒素生成と機能遺伝子発現の関係
日本土壌肥料学会2014年度東京大会
2014年09月01日, その他 - 落水後の水田土壌から排出される亜酸化窒素放出機構の解明
化学工学会第79年会
2014年03月01日, ポスター発表 - 豚ふん尿と河川敷のバイオマスとの高温乾式メタン発酵特性の解明
化学工学会第79年会
2014年03月01日, ポスター発表 - 乾式メタン発酵残渣を施肥した多収米飼料イネ栽培における温室効果ガス排出量の把握と削減
第16回化学工学会学生発表会
2014年03月01日, その他 - 乾式メタン発酵残渣を施用した多収米飼料イネ水田における窒素挙動の把握
第16回化学工学会学生発表会
2014年03月01日, その他 - 乾式メタン発酵残渣を施用した多収米飼料イネ水田における窒素挙動の評価
化学工学会第79年会
2014年03月, ポスター発表 - 土壌からの亜硝酸ガス（HONO）フラックスの定量および大気濃度への寄与
第19回大気化学討論会
2013年11月07日, ポスター発表 - 部分硝化型活性汚泥バイオリアクターにおける亜酸化窒素放出と放出特性の解明：ヒドロキシルアミンの影響
第29回日本微生物生態学会大会
2013年11月01日, ポスター発表 - 水田中に棲息する脱窒性メタン細菌の空間分布と系統学的評価
第29回日本微生物生態学会大会
2013年11月01日, ポスター発表 - 追肥前落水が畜産排水を施肥した飼料イネ水田のCH4排出並びにCH4生成古細菌に及ぼす影響
第29回日本微生物生態学会大会
2013年11月01日, その他 - Dry-thermophilic anaerobic co-digestion of swine manure mixed with forage rice straw
International Conference on Recent Advances in Pollution Control and Resource Recovery for the Livestock Farming Industry
2013年10月01日, その他 - Simultaneous Reduction of CH4 and N2O Emissions from a Forage Rice Field Fertilized with High-Load of Livestock Wastewater by Water Management and Fertilization Pattern
International Conference on Recent Advances in Pollution Control and Resource Recovery for the Livestock Farming Industry
2013年10月01日, その他 - Sustainable Treatment System for Waste from Livestock Farming Industry Based on Dry Thermophilic Anaerobic Digestion Process and Forage Rice Paddy Field
International Conference on Recent Advances in Pollution Control and Resource Recovery for the Livestock Farming Industry
2013年10月01日, その他 - 畜産排水を施肥した飼料イネ水田におけるCH4およびN2Oの同時削減-水管理と施肥方法の検討-
日本土壌肥料学会2013年度名古屋大会
2013年09月12日, その他 - Implications of predominant ammonia oxidizing bacteria and reactor conditions on nitrous oxide production from a partial nitrifying bioreactor
3rd International Conference on Nitrification
2013年09月01日, その他 - Spatio-temporal analysis of nitrous oxide production and emission after drainage of flooded soil
3rd International Conference on Nitrification
2013年09月01日, その他 - Dry Thermophilic Anaerobic Digestion Process of Swine Manure and Rice Straw: Towards a Sustainable Swine Manure Treatment System Based on Forage Rice Paddy
3rd International Congress on Sustainability Science and Engineering
2013年08月01日, 口頭発表（招待・特別） - The Effect of Community Structure of Ammonia Oxidizing Bacteria on Potential of Nitrous Oxide Production from a Nitrifying Bioreactor
9th World Congress of Chemical Engineering
2013年08月01日, ポスター発表 - Influence of water management and residue of dry thermophilic anaerobic co-digestion with pig manure and rice straw on water quality and greenhouse gas emission from paddy soil planted with forage rice
International Workshop on Non-point Source Pollution Control and Clean Agriculture
2013年08月, その他 - 大型糸状緑藻を生育させた水路における農地排水処理
化学工学会 第78年会
2013年03月17日, その他 - 畜産排水を施肥した飼料イネ水田におけるCH4およびN2Oの同時削減の試み
化学工学会 第78年会
2013年03月17日, その他 - 部分硝化型バイオリアクターで優先化された異なるアンモニア酸化細菌群の亜酸化窒素生成ポテンシャルと経路の解析
第47回日本水環境学会年会
2013年03月13日, その他 - 異なる水環境におけるAnammox反応活性の評価
第47回日本水環境学会年会
2013年03月13日, その他 - 空間分布解析による落水後の水田における突発的な亜酸化窒素排出挙動の解明
第47回日本水環境学会年会
2013年03月13日, その他 - 畜産排水を施肥した飼料イネ水田のメタン放出挙動とメタンをめぐる微生物群のダイナミクス
第64回日本生物工学会大会
2012年10月26日, その他 - 畜産排水を多量施肥した飼料イネ水田より発生する温室効果ガスの抑制に関する研究
第15回日本水環境学会シンポジウム
2012年09月10日, その他 - 畜産排水を施肥した水田におけるメタン放出の挙動とメタン酸化細菌の関係解析
第46回日本水環境学会年会
2012年03月16日, その他 - 畜産排水を施肥した水田における亜酸化窒素の動態とアンモニア酸化に関与する遺伝子発現解析
第46回日本水環境学会年会
2012年03月16日, その他 - 酸素分圧の違いがアンモニア酸化細菌の群集構造と亜硝酸蓄積・亜酸化窒素放出へ及ぼす影響
第46回日本水環境学会年会
2012年03月14日, その他 - Nitrogen Dynamics in Forage Rice Field Treating Liquid Cattle Waste
The 4th IWA-ASPIRE Conference & Exhibition
2011年11月01日, その他 - 飼料イネ水田を利用した温室効果ガス低排出型畜産排水処理の開発
第14回日本水環境学会シンポジウム
2011年09月10日, その他 - 飼料イネ水田による畜産排水処理における温室効果ガス排出
第45回日本水環境学会年会
2011年03月18日, その他 - Measurement of nitrification and denitrification rate under different infiltration rates in paddy soil using 15N tracer
12th International Conference on Wetland Systems for Water Pollution Control
2010年10月01日, ポスター発表 - GHG (Methane and Nitrous Oxide) Emissions from Forage Rice Field Applied with Liquid Cattle Waste
12th International Conference on Wetland Systems for Water Pollution Control
2010年10月01日, ポスター発表 - Effect of infiltration rate on nitrogen dynamics in paddy soil after high-load nitrogen application containing 15N tracer
3rd WETLAND POLLUTANT DYNAMICS AND CONTROL -WETPOL 2009
2009年09月01日, その他 - 飼料イネ人工湿地における河川水浄化と温室効果ガス放出
日本水処理生物学会第45回大会
2008年11月14日, その他