Article
Ecology
Xin Sun, Amal Jayakumar, John C. Tracey, Elizabeth Wallace, Colette L. Kelly, Karen L. Casciotti, Bess B. Ward
Summary: The study expands N2O consumption measurements from anoxic zones to oxic waters, revealing differences in the characteristics of N2O-consuming microbes. Experimental results suggest that microbes in the dynamic layer with steep oxygen and N2O gradients above the oxygen deficient zone play a significant role in N2O consumption.
Article
Engineering, Environmental
Yi-Xuan Chu, Jing Wang, Lei Jiang, Guangming Tian, Ruo He
Summary: This study compared N2O emissions from bioreactor landfills with different ventilation methods and found that continuous aeration was more favorable for the biodegradation of organic matter. Both intermittent and continuous aeration effectively removed nitrogen compounds from leachate. The denitrifying bacterial community in the landfill was influenced by the stabilization and nitrogenous compound concentrations in the waste and leachate.
Article
Environmental Sciences
B. Read-Daily, S. Ben Maamar, F. Sabba, S. Green, R. Nerenberg
Summary: This study found that N2O has a significant impact on mixed denitrifying communities. The presence of N2O alone selects for a low-diversity, fully denitrifying community, while the presence of N2O with NO2- or NO3- promotes more diverse microbial communities.
Article
Biotechnology & Applied Microbiology
Rui Yang, Lin-jiang Yuan, Ru Wang, Gang Wang, Miao Zhu
Summary: The study demonstrates that Nir activity can be used as an indicator for characterizing changes in N2O emissions. The N2O emission and its proportion were least at an aeration intensity of 0.8 L.min(-1), while Nir activity was relatively high at an aeration intensity of 0.6 L.min(-1). Additionally, Nir activity showed a high affinity for nitrite and was not directly affected by DO.
BIOCHEMICAL ENGINEERING JOURNAL
(2022)
Article
Environmental Sciences
Sampriti Kataki, Rupam Patowary, Soumya Chatterjee, Mohan G. Vairale, Sonika Sharma, Sanjai K. Dwivedi, Dev Vrat Kamboj
Summary: Environmental consequences of wastewater management and the potential bioaerosolization of pathogens during treatment processes are crucial considerations, especially in preventing disease transmission. Understanding and implementing control strategies for aerosol-based transmission in wastewater treatment plants are essential for mitigating risks, particularly during pandemic situations.
Article
Environmental Sciences
Xinhui Wang, Baoyu Xiang, Ji Li, Menghui Zhang, Asa Frostegard, Lars Bakken, Xiaojun Zhang
Summary: This study demonstrates a strategy to engineer the soil microbiome with promising non-denitrifying nitrous oxide-reducing bacteria (NNRB), and shows the potential of these strains in reducing N2O emissions from agricultural soils.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Environmental Sciences
Maosheng Zheng, Nan Zhou, Shishi He, Fang Chang, Jie Zhong, Shuo Xu, Zhe Wang, Tang Liu
Summary: This study systematically investigated N2O emissions from a pilot-scale Carrousel oxidation ditch under different COD/N ratios and aeration rates, revealing that high internal recycle ratio and air stripping effect are important factors in reducing N2O emissions. Additionally, simulated shock-load conditions showed that autotrophic nitrification process generates more N2O under these conditions.
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2021)
Article
Environmental Sciences
Junliang Gao, Rui Wang, Yilin Li, Huimin Huang, Xiaomei Su, Zijing An, Wenjun Yin, Lizhen Yang, Liang Rong, Faqian Sun
Summary: The effect of two aeration modes in the aerobic phase on nitrogen removal and N2O emission in treating landfill leachate was compared. Increasing dissolved oxygen showed positive effects on nitrogen removal and minimized N2O emission. However, high dissolved oxygen concentration reduced nitrogen removal and led to high N2O emission.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Biodiversity Conservation
Yang Zhan, Zhisheng Yao, Peter M. Groffman, Junfei Xie, Yan Wang, Guangtao Li, Xunhua Zheng, Klaus Butterbach-Bahl
Summary: Urban land-use change affects biogeochemical cycling of carbon and nitrogen and associated greenhouse gas (GHG) emissions. A meta-analysis shows that urbanization increases soil nitrous oxide (N2O) emissions and reduces soil methane (CH4) uptake. These changes are driven by alterations in soil properties, such as bulk density and pH, temperature increase, and management practices, particularly fertilizer use.
GLOBAL CHANGE BIOLOGY
(2023)
Article
Engineering, Environmental
Yanying He, Yingrui Liu, Xuecheng Li, Tingting Zhu, Yiwen Liu
Summary: This study aims to uncover the roles of biofilm in reducing N2O emission in a nitrifying IFAS system, using advanced technologies such as N2O microsensor and site-preference analysis. The biofilm was found to reduce N2O emission by inhibiting nitrite accumulation and promoting endogenous denitrification. It also reduced N2O emission by decreasing the dissolved oxygen level. The presence of biofilm in the IFAS system resulted in significantly lower N2O emissions compared to the solo sludge flocs, and this can be attributed to the high microbial diversity and unique enzyme composition of the biofilm.
Article
Environmental Sciences
Yaohao Hu, Jiapeng Wu, Jiaqi Ye, Xiaohan Liu, Yu Wang, Fei Ye, Yiguo Hong
Summary: This study investigates the dissolved N2O and potential NPR, NRR, and NER as well as key functional genes related to N2O transformation in the Pearl River Estuary. The results show that higher N2O emission potential and NPR values were found in the upstream and midstream regions, while higher NRR values were detected in downstream. Additionally, nirS and nirK type N2O producers dominate the upstream zone, while abundant N2O reducers, especially nosZ II type N2O reducers, are observed in downstream. The gene abundance ratio (Rnir/nosZ) is significantly correlated with N2O emission potential (Re). Overall, this study highlights the influence of an imbalance between N2O production and reduction by multi-bacterial communities on N2O emission potential in estuarine sediments.
MARINE ENVIRONMENTAL RESEARCH
(2023)
Article
Soil Science
Alison E. King, Fereidoun Rezanezhad, Claudia Wagner-Riddle
Summary: Experimental results suggest that aggregate disruption may not be the main factor providing substrates for N2O emissions, while longer freezing durations may lead to larger N2O emissions associated with a decrease in microbial biomass.
SOIL BIOLOGY & BIOCHEMISTRY
(2021)
Article
Biotechnology & Applied Microbiology
Yiwen Zhou, Toshikazu Suenaga, Chuang Qi, Shohei Riya, Masaaki Hosomi, Akihiko Terada
Summary: This study investigates the effects of temperature and oxygen exposure on the biokinetics of N2O-reducing bacteria (N2ORB). The results show that different N2ORB can adapt to varying temperatures and oxygen concentrations, indicating distinct physiological characteristics. This knowledge can aid in developing mitigation strategies tailored to the predominant N2ORB physiologies.
BIOTECHNOLOGY AND BIOENGINEERING
(2021)
Article
Soil Science
Arpita Maheshwari, Christopher M. Jones, Maren Tiemann, Sara Hallin
Summary: Agricultural soils are a major source of N2O, a potent greenhouse gas and ozone-depleting substance. The role of carbon availability in shaping the structure of N2O reducing communities in soil has not been explored. Our study shows that the effect of carbon addition on the abundance and diversity of N2O reducing genes varies with different carbon substrates in contrasting soil types, highlighting the importance of specific carbon substrates in selecting certain lineages of N2O reducers.
SOIL BIOLOGY & BIOCHEMISTRY
(2023)
Article
Soil Science
Xiaoyi Meng, Chun Ma, Soren O. Petersen
Summary: Manure is a key source of nitrogen for crops, but it also contributes to N2O emissions from soil. The effects of different treatments on N2O emissions are still uncertain.
BIOLOGY AND FERTILITY OF SOILS
(2022)
Article
Engineering, Environmental
Yiwen Zhou, Shuting Zhao, Toshikazu Suenaga, Megumi Kuroiwa, Shohei Riya, Akihiko Terada
Summary: This study evaluated the physiologies of two N2O-reducing bacteria, showing their potential as N2O sinks in the presence of NO2- and N2O. The activities of these N2ORB were significantly affected by high NO2- concentrations and acidic conditions, increasing the risk of N2O emissions.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Biotechnology & Applied Microbiology
Jingyu Duan, Hop Van Phan, Hiroki Tsukamoto, Tomoyuki Hori, Akihiko Terada
Summary: Shifting from conventional ammonia removal to recovery is crucial for addressing environmental problems and resource scarcity. A study on a microaerophilic activated sludge (MAS) system showed that it has the potential to efficiently remove chemical oxygen demand (COD) while retaining ammonia. The biokinetic analysis and mathematical modeling revealed the optimal operating conditions for achieving high COD removal efficiencies, ammonia retention efficiencies, and low N2O emission factors in the MAS system.
BIOCHEMICAL ENGINEERING JOURNAL
(2023)
Article
Environmental Sciences
Muchun Zhou, Chuanqiao Zhou, Yu Peng, Ruoyu Jia, Wenpeng Zhao, Shuoyuan Liang, Xiaoguang Xu, Akihiko Terada, Guoxiang Wang
Summary: Lacustrine eutrophication, a major contributor to carbon emissions, poses challenges in accurately estimating carbon emissions from lakes. This study used a space-for-time substitution approach to examine carbon emissions from eight lakes and Lake Taihu over one year. The results showed that eutrophication promoted carbon production potential, dissolved carbon concentrations, and carbon release fluxes, particularly CH4. However, the space-for-time substitution method led to an overestimation of the impact of eutrophication on carbon emissions, especially with the intensification of eutrophication.
ENVIRONMENTAL RESEARCH
(2023)
Review
Environmental Sciences
Shuting Zhao, Taoran Shi, Akihiko Terada, Shohei Riya
Summary: The first global-scale assessment of Sb contamination in soil related to mining/smelting activities was conducted based on 91 articles published between 1989 and 2021. The study analyzed the geographic variation, pollution levels, speciation, influencing factors, and environmental effects of Sb in mining/smelting-affected soils. High Sb values were found in both developed (Poland, Italy, Spain, Portugal, New Zealand, Australia) and developing (China, Algeria, Slovakia) countries. Most mining areas reported soil Sb concentrations that exceeded WHO's recommended maximum permissible limit. The study highlights the importance of standardizing extraction methods for Sb speciation and the potential non-carcinogenic health risks from Sb ingestion through crop consumption.
INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH
(2023)
Article
Agronomy
Shota Shirane, Noriaki Momma, Toshiyuki Usami, Chiharu Suzuki, Tomoyuki Hori, Tomo Aoyagi, Seigo Amachi
Summary: Anaerobic soil disinfestation (ASD) is an ecofriendly alternative to chemical fumigation for eliminating soil-borne plant pathogens. This study found that caproate, produced by a specific strain of bacteria, is a key disinfestation factor in ethanol-based ASD, and the direct application of caproate to soil could be a promising strategy for rapid and stable soil disinfection.
Article
Engineering, Environmental
Hiroki Tsukamoto, Hop V. Phan, Toshikazu Suenaga, Shohei Yasuda, Megumi Kuroiwa, Shohei Riya, Atsushi Ogata, Tomoyuki Hori, Akihiko Terada
Summary: This study validated a microaerophilic activated sludge system for efficient ammonia retention and organic carbon removal from nitrogenous wastewater. The system controlled dissolved oxygen concentrations and solids retention times to mitigate N2O emissions and suppress ammonia-oxidizing microorganisms, achieving successful nitrogen management.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2023)
Article
Engineering, Chemical
Jizhong Meng, Lin Shi, Shun Wang, Zhenhu Hu, Akihiko Terada, Xinmin Zhan
Summary: Electrodialysis (ED) is a potential technique for nutrient recovery from digestate, but fouling caused by dissolved organic matter (DOM) remains a challenge. This study investigated the effect of molecular size on DOM fouling in ED membranes using an ultrafiltration-ED design. It was found that the fouling of anion-exchange membranes was significantly influenced by molecular size, while the cation-exchange membranes were antifouling. DOM with a molecular size smaller than 10 kDa caused the most significant deterioration of the anion-exchange membrane.
JOURNAL OF MEMBRANE SCIENCE
(2023)
Article
Environmental Sciences
Chuanqiao Zhou, Muchun Zhou, Ruoyu Jia, Yu Peng, Fenjun Zhao, Runze Xu, Shuoyuan Liang, Akihiko Terada, Guoxiang Wang, Tsuyoshi Kinouchi, Xiaoguang Xu
Summary: Lakes play an important role in methane emissions and particulate organic carbon (POC) production, known as the methane paradox. However, the source of POC during eutrophication and its impact on methane emissions are still unclear. This study investigated 18 shallow lakes with different trophic states to understand the source of POC and its contribution to methane production. The findings suggest that cyanobacteria-derived carbon is a significant source of POC, and the intensified eutrophication increases POC concentration, promoting methane production and emission fluxes.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Environmental Sciences
Yang Bai, Huanhuan Hu, Po-Heng Lee, Ainur Zhussupbekova, Igor Shvets, Bang Du, Akihiko Terada, Xinmin Zhan
Summary: Iron sulfides-based autotrophic denitrification (IAD) can effectively treat nitrate-contaminated wastewater. This study reveals the chemical reduction of nitrate to ammonium by iron sulfides under ambient conditions, which has been overlooked in IAD reactors. The biofilter of IAD system showed complex nitrogen transformations involving chemical reduction, autotrophic denitrification, dissimilatory nitrate reduction to ammonium (DNRA), and sulfate reducing ammonium oxidation (Sulfammox), facilitated by functional microbial communities.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Engineering, Environmental
Xinyi Zhou, Taku Fujiwara, Taira Hidaka, Fumitake Nishimura, Tomohiro Nakanishi, Akihiko Terada, Tomoyuki Hori
Summary: In this study, a microaerobic activated sludge process (MAS) was proposed as a pretreatment method to retain NH4-N from high-strength nitrogenous wastewater. The MAS systems achieved high NH4-N retention rates and TOC removal rates. The emissions of CO2 and N2O during MAS were evaluated, and the mechanisms of N2O emission from each reactor were investigated. The study highlighted the importance of N2O mitigation in the MAS process, especially under acidic conditions.
Article
Engineering, Environmental
Ralph Rolly Gonzales, Keizo Nakagawa, Kazuo Kumagai, Susumu Hasegawa, Atsushi Matsuoka, Zhan Li, Zhaohuan Mai, Tomohisa Yoshioka, Tomoyuki Hori, Hideto Matsuyama
Summary: This study demonstrates a hybrid osmotically assisted reverse osmosis (OARO) and reverse osmosis (RO) process for the enrichment and recovery of ammoniacal nitrogen in wastewater, resulting in energy-saving and economic benefits.
Article
Microbiology
Shohei Yasuda, Akihiko Terada
Summary: This article describes the complete genome sequence of a Gamma-proteobacteria marine bacterium D49 isolated from activated sludge treating landfill leachate, which contains functional genes for the biosynthesis of ectoine. The deciphering of the genome contributes to ectoine production by this strain.
MICROBIOLOGY RESOURCE ANNOUNCEMENTS
(2023)
Article
Engineering, Environmental
Kohei Oba, Toshikazu Suenaga, Megumi Kuroiwa, Shohei Riya, Akihiko Terada
Summary: In denitrifying reactors, different canonical complete denitrifying bacteria show variations in NO3- and N2O consumption rates. The Clade II nosZ bacterium Azospira sp. strain I13 acts as an N2O sink, while the Clade I nosZ bacteria Pseudomonas stutzeri strain JCM 5965 and Alicycliphilus denitrificans strain I51 exert an effect on NO3-. These findings are valuable for developing N2O mitigation strategies.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2022)
Article
Biotechnology & Applied Microbiology
Mamoru Oshiki, Yuka Toyama, Toshikazu Suenaga, Akihiko Terada, Yasuhiro Kasahara, Takashi Yamaguchi, Nobuo Araki
Summary: Agricultural soil plays a crucial role in mitigating the emission of N2O gas, and this study examined the N2O reduction activities of Gemmatimonadetes bacteria and their abundance in agricultural soil samples. The results showed that the Gemmatimonas aurantiaca bacteria exhibited the highest N2O reduction activity at pH 7 and 30°C. Additionally, the abundance of Gemmatimonadetes bacteria and specific OTUs correlated with the N2O reduction rates in the soil samples, suggesting their involvement in N2O reduction.
MICROBES AND ENVIRONMENTS
(2022)
