Article
Environmental Sciences
Tanya Valkova, Vanessa Parravicini, Ernis Saracevic, Joseph Tauber, Karl Svardal, Jorg Krampe
Summary: N2O emissions in activated sludge tanks are mainly influenced by the activity of nitrifying bacteria and the efficiency of heterotrophic denitrification. Low-loaded plants achieving high nitrogen removal exhibit lower N2O emission intensity. The regression analysis shows a negative linear correlation between the N2O emission factor and the total nitrogen removal degree of the plants.
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2021)
Article
Environmental Sciences
Sakae Toyoda, Takahito Kakimoto, Kushi Kudo, Naohiro Yoshida, Daisuke Sasano, Naohiro Kosugi, Masao Ishii, Sohiko Kameyama, Mahomi Inagawa, Hisayuki Yoshikawa-Inoue, Shigeto Nishino, Akihiko Murata, Shigeyuki Ishidoya, Shinji Morimoto
Summary: Ocean-atmosphere gas exchange in the Arctic Ocean is sensitive to global warming because the decrease of sea-ice covered area enhances the exchange. The isotopic signatures of dissolved N2O in the Chukchi Sea shelf indicate a mixture of N2O produced in the bottom water and that of atmospheric origin.
GLOBAL BIOGEOCHEMICAL CYCLES
(2021)
Article
Agricultural Engineering
Jinyu Ye, Huan Gao, Carlos Domingo-Felez, Junkang Wu, Manjun Zhan, Ran Yu, Barth F. Smets
Summary: Cerium dioxide nanoparticles have a significant impact on nitrogen transformation processes and N2O emission in wastewater treatment systems, decreasing NH4+ -N removal efficiency and increasing N2O emission. Although NH4+ -N removal efficiency can recover after a period of restoration, N2O emission levels remain higher.
BIORESOURCE TECHNOLOGY
(2022)
Article
Soil Science
Nadine Loick, Elizabeth Dixon, G. Peter Matthews, Christoph Mueller, Veronica S. Ciganda, Maria Lopez-Aizpun, Miguel A. Repullo, Laura M. Cardenas
Summary: This study quantifies the production and consumption pathways of N2O in soil using labelled substrate-N, showing the impact of different water filled pore space on N-transformation processes and emissions. The research highlights the importance of heterotrophic nitrification and denitrification in the N2O emissions, demonstrating the complex relationship between water filled pore space and nitrogen transformations.
Article
Environmental Sciences
Morten Lykkegaard Christensen, Anne Hojmark Jakobsen, Cecilie Sofie Kragelund Hansen, Mads Skovbjerg, Rikke Bruun Munk Andersen, Mette Dam Jensen, Kim Sundmark
Summary: This article describes a wastewater treatment plant designed to focus equally on energy production, water quality, and reduced emissions of greenhouse gases. The plant utilizes a disk filter to remove carbon during primary treatment, followed by hydrolysis and centrifugation to produce a hydrolysate centrate that can be used for secondary wastewater treatment or biogas production.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Review
Chemistry, Multidisciplinary
Ncumisa Mpongwana, Sudesh Rathilal
Summary: This review explores the properties of biofilms that can be exploited to enhance biological wastewater systems. It reveals that various biofilm properties, such as extracellular polymeric substances (EPS), quorum sensing (Qs), and acylated homoserine lactones (AHLs), can be enhanced to improve biofilm technology for wastewater treatment processes. The review also emphasizes the importance of exploiting these properties in simultaneous nitrification and denitrification and biological phosphorus removal processes.
APPLIED SCIENCES-BASEL
(2022)
Review
Engineering, Environmental
Nam-Hoon Lee, Sang-Hoon Song, Min-Jung Jung, Ran-Hui Kim, Jin-Kyu Park
Summary: This study outlines the dynamics of N2O in solid waste landfills and its emissions. N2O is mainly generated through denitrification and to a lesser extent, nitrification in anaerobic landfills. Landfill leachate treatment processes also contribute to significant N2O emissions. Bioreactor landfills emit more N2O than traditional anaerobic landfills due to various pathways such as NH2OH oxidation, nitrifier denitrification, and heterotrophic denitrification. Factors like C/N ratio, NH3 oxidation rate, redox conditions, and temperature affect these processes. Addressing N2O emissions from landfills is crucial for an integrated nitrogen management strategy.
ENVIRONMENTAL ENGINEERING RESEARCH
(2023)
Article
Agronomy
Qiurui Zhu, Eric A. Davidson, Jacob G. Hagedorn, Mark S. Castro, Thomas R. Fisher, Rebecca J. Fox, Shannon E. Brown, James W. Lewis
Summary: Drainage water management (DWM) is an effective practice to reduce nitrate export from croplands, but it may increase greenhouse gas emissions. This study evaluated the effects of DWM on greenhouse gas emissions and found no significant difference in emissions between DWM and non-DWM fields.
AGRICULTURAL AND FOREST METEOROLOGY
(2023)
Article
Multidisciplinary Sciences
Jianyu Yuan, Lijuan Yan, Guang Li, Mahran Sadiq, Nasir Rahim, Jiangqi Wu, Weiwei Ma, Guorong Xu, Mengyin Du
Summary: This study investigated the effects of conservation tillage techniques on soil N2O emission and yield in a semi-arid region of the Loess Plateau in Dingxi, China. The results showed that conservation tillage techniques improved soil physicochemical properties, increased organic carbon and nutrient content, and enhanced crop yield. Additionally, the impact of conservation tillage on soil N2O emission was relatively small, making it the recommended tillage strategy for the semi-arid environmental zone of the Loess Plateau.
SCIENTIFIC REPORTS
(2022)
Article
Multidisciplinary Sciences
Yueyue Si, Yizhu Zhu, Ian Sanders, Dorothee B. Kinkel, Kevin J. Purdy, Mark Trimmer
Summary: This study found that freshwater communities are capable of fixing both N-2 and N2O, with different seasonalities and temperature dependencies. N2O fixation is less sensitive to temperature compared to N-2 fixation, resulting in a strong sink for N2O in colder months.
NATURE COMMUNICATIONS
(2023)
Review
Environmental Sciences
Khushboo Gupta, Raushan Kumar, Kushal Kumar Baruah, Samarendra Hazarika, Susmita Karmakar, Nirmali Bordoloi
Summary: Agricultural soil, especially rice paddies, play a significant role in emitting greenhouse gases such as methane and nitrous oxide. Understanding the mechanisms and factors influencing the production and release of these gases is crucial in developing strategies to reduce emissions and mitigate global climate change impacts.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2021)
Article
Chemistry, Multidisciplinary
Pauline Sophie Rummel, Reinhard Well, Johanna Pausch, Birgit Pfeiffer, Klaus Dittert
Summary: Returning crop residues to agricultural fields can increase CO2 emissions and impact N2O and NO emissions, with different soil oxidation conditions promoting denitrification. The study found that maize litter can increase total CO2 emissions, but NO and N2O emissions were low under oxic conditions due to limited denitrification. Additionally, bacterial processes dominated N2O formation in the beginning, with a shift towards fungal denitrification later on.
APPLIED SCIENCES-BASEL
(2021)
Article
Agronomy
Ziyi Feng, Yongxiang Yu, Huaiying Yao, Chaorong Ge
Summary: This study found that the presence of ZnO nanoparticles can increase N2O emissions in soil, especially when coupled with C and N substrate amendments. The action of ZnO NPs promotes nitrification and denitrification processes, further impacting the functional genes associated with N2O emissions.
Article
Agriculture, Multidisciplinary
Hui-Min Zhang, Zhi Liang, Yong Li, Zhao-Xiong Chen, Jin-Bo Zhang, Zu-Cong Cai, Lars Elsgaard, Yi Cheng, Kees Jan van Groenigen, Diego Abalos
Summary: Liming, a management practice used worldwide to reduce the negative effects of acidification in soils, has been found to have a significant impact on greenhouse gas emissions. This global meta-analysis study shows that liming can reduce nitrous oxide (N2O) emissions by increasing the abundance of N2O reductase genes and decreasing the fungi:bacteria ratio in soil. It also suggests that liming can reduce methane (CH4) emissions and the abundance of methanogens, but has no effect on CH4 uptake and methanotrophs. Additionally, liming increases soil carbon dioxide (CO2) emissions due to higher respiration. The study highlights the importance of considering soil microbial communities in understanding and mitigating greenhouse gas emissions in response to liming.
AGRICULTURE ECOSYSTEMS & ENVIRONMENT
(2022)
Article
Environmental Sciences
Vanessa Parravicini, Per Henrik Nielsen, Dines Thornberg, Alberto Pistocchi
Summary: We present an assessment of greenhouse gas emissions from urban wastewater treatment plants in Europe, and propose solutions to reduce these emissions. Our assessment considers various factors that contribute to emissions, such as infrastructure, sewer networks, treatment processes, and the composition of treated effluents.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Environmental Sciences
Zhongzhong Wang, Shun Wang, Sihuang Xie, Yan Jiang, Jizhong Meng, Guangxue Wu, Yuansheng Hu, Xinmin Zhan
Summary: The study found that the addition of biochar has a slight increase in specific methane yield in dry anaerobic digestion, especially in the degradation of poorly biodegradable organics. However, the supplementation of biochar did not significantly affect the peak methane production rate, possibly due to the important role of enhancing electron transfer mechanism.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2022)
Article
Environmental Sciences
Tianle Li, Bo Li, Yuepeng Sun, Guangxue Wu
Summary: The effects of sludge retention times (SRTs) on system performance, microbial structure, and quorum sensing were investigated in an activated sludge bioreactor. Short SRTs resulted in higher removal efficiency of inorganic nitrogen (TIN) and enrichment of specific bacteria and genes. Additionally, an abundance of quorum sensing signals was found in the sludge at short SRTs.
WATER AIR AND SOIL POLLUTION
(2022)
Article
Multidisciplinary Sciences
Dan Wang, Weili Ye, Guangxue Wu, Ruoqi Li, Yuru Guan, Wei Zhang, Junxia Wang, Yuli Shan, Klaus Hubacek
Summary: This study aims to construct a greenhouse gas (GHG) emission inventory for wastewater treatment plants (WWTPs) in China to support their emission reduction efforts. The inventory includes CH4, N2O, and CO2 emissions from different treatment processes, energy consumption, and effluent discharge, covering the period from 2006 to 2019.
Article
Agricultural Engineering
Jin Du, Qidong Yin, Xingzhao Zhou, Qiannan Guo, Guangxue Wu
Summary: This study evaluated the cross-feeding function by analyzing microbial aggregates in anaerobic digesters and found complementary genetic potential for amino acid synthesis between syntrophs and methanogens, implying potential cross-feeding partnership.
BIORESOURCE TECHNOLOGY
(2022)
Article
Engineering, Environmental
Zhongzhong Wang, Shun Wang, Yuansheng Hu, Bang Du, Jizhong Meng, Guangxue Wu, He Liu, Xinmin Zhan
Summary: The shift from acetoclastic to hydrogenotrophic pathway in methanogenesis under ammonia inhibition is a common phenomenon. This study investigated the ammonia tolerance and recovery of acetoclastic and hydrogenotrophic methanogens in anaerobic digestion. The results showed that hydrogenotrophic methanogens had higher tolerance to ammonia than acetoclastic methanogens, but were more adversely affected by NH4+ at pH≤8.0.
Article
Engineering, Chemical
Qidong Yin, Guangxue Wu, Piet N. L. Lens
Summary: This study investigates the impact of acidogenic microorganisms and environmental factors on the production of volatile fatty acids (VFAs) and alcohols. The microbial communities and metabolic potential were analyzed using high-throughput sequencing, revealing the importance of core features and their response to environmental changes. The electrode potential was found to be the most significant environmental variable affecting the distribution of core features and fermentation pathways.
Article
Environmental Sciences
Xinyue Ma, Ziyan Cheng, Wenjing Bai, Rui Tang, Guangxue Wu, Xinmin Zhan, Zhen-Hu Hu
Summary: Intensive animal farming generates a large volume of digested liquid, and excessive application can lead to pollution of surface water and groundwater. This study investigates the use of Ca(ClO)2 pretreatment to enhance SS flocculation removal in digested dairy wastewater. Results show that Ca(ClO)2 pretreatment combined with PAC flocculation can effectively remove SS and improve the removal of chemical oxygen demand and phosphorus.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Agricultural Engineering
Bang Du, Mengqi Gu, Zhenhu Hu, Xinmin Zhan, Guangxue Wu
Summary: Anaerobic ethanol oxidation can be thermodynamically unfavourable under standard conditions, but can become exergonic with extracellular electron transfer (EET) through microbial redox-active proteins (RAP). This study evaluates the thermodynamic effects of the fraction of substrate degraded through EET, product feedback, distribution of electrons from EET between acetotrophic and hydrogenotrophic methanogenesis, and the redox potential of RAP on anaerobic ethanol oxidation. The results show that ethanol oxidation can occur when the redox potential is above -0.408 V with EET or when product concentration is below a certain threshold. The appropriate redox potential ranges for active acetotrophic and hydrogenotrophic methanogens were determined. The EET fraction and electron distribution were found to be key factors in maintaining biomass yields and influencing the ratio of methanogens.
BIOMASS & BIOENERGY
(2023)
Review
Green & Sustainable Science & Technology
Zhongzhong Wang, Yuansheng Hu, Shun Wang, Guangxue Wu, Xinmin Zhan
Summary: The dry anaerobic digestion (AD) process is a promising technology for the treatment and stabilization of high-solid organic waste, with advantages such as higher methane yield and reduced digester size. However, it still faces challenges due to the excessive solids content and differences from wet AD in terms of operation and design. It is important to understand the characteristics of dry AD, analyze operational factors, and evaluate optimization methods to develop practical applications.
RENEWABLE & SUSTAINABLE ENERGY REVIEWS
(2023)
Article
Agricultural Engineering
Jin Du, Xingzhao Zhou, Qidong Yin, Jiane Zuo, Guangxue Wu
Summary: This study explores the effects of operational parameters on microbial communities in anaerobic digestion (AD) with sulfate. It finds that reactors in rapid-filling mode exhibit fast kinetic properties, while reactors in slow-filling mode can mitigate propionate accumulation. Taxonomic and functional analysis further support the suitability of rapid- and slow-filling modes for the growth of r-strategists (such as Desulfomicrobium) and K-strategists (such as Geobacter), respectively.
BIORESOURCE TECHNOLOGY
(2023)
Article
Environmental Sciences
Bang Du, Zhongzhong Wang, Piet N. L. Lens, Xinmin Zhan, Guangxue Wu
Summary: This study investigated the performance, syntrophic relationships, microbial communities, and metabolic pathways of ethanol-fed reactors with different operational modes and solids retention times. The results showed that different microorganisms were enriched under different SRT conditions, and syntrophic bacteria related to methane production could be enriched under low SRT conditions.
ENVIRONMENTAL RESEARCH
(2024)
Article
Engineering, Environmental
Wenjing Bai, Rui Tang, Guangxue Wu, Wei Wang, Shoujun Yuan, Liwen Xiao, Xinmin Zhan, Zhen-Hu Hu
Summary: This study investigated the distribution of heavy metals in suspended solids (SS) and their influence on co-precipitation during struvite recovery from digested swine wastewater. The results showed that the concentration of heavy metals in the wastewater ranged from 0.05 to 17.05 mg/L. During struvite generation, 56.9-80.3% of individual heavy metals were co-precipitated. These findings provide a potential way for controlling the co-precipitation of heavy metals in struvite.
JOURNAL OF HAZARDOUS MATERIALS
(2023)
Article
Engineering, Environmental
Wenjing Bai, Rui Tang, Guangxue Wu, Wei Wang, Shoujun Yuan, Liwen Xiao, Xinmin Zhan, Zhen-Hu Hu
Summary: Struvite recovered from wastewater contains significant amounts of fecal indicator bacteria, porcine adenoviruses, and antibiotic resistance genes, which can pose potential risks. This study investigated the co-precipitation behavior of these pathogens and genes with suspended solids (SS) and found that high-density SS contributed more to the co-precipitation than low-density SS. Furthermore, the presence of SS in struvite hindered the inactivation of bacteria and genes during drying. These findings suggest that removing high-density SS prior to struvite recovery can effectively control the co-precipitation and inactivation of pathogens and genes.
JOURNAL OF HAZARDOUS MATERIALS
(2023)
Article
Biotechnology & Applied Microbiology
Yuyin Wang, Guangxue Wu
Summary: Antibiotics like tetracycline in wastewater can lead to operational failure of anaerobic digestion systems, inhibiting COD removal, causing VFAs accumulation, reducing methane production, and impacting microbial communities. CFRs performed better in COD shock loading recovery, propionate degradation, and methane production. Additionally, CFRs exhibited superior tetracycline removal capacity compared to SBRs. Biodegradation was found to be the primary pathway for tetracycline removal, and long-term tetracycline exposure affected archaea abundances and enrichment of hydrolytic-acidogenic bacteria. CFRs provided a more conducive environment for the enrichment of these microorganisms.
ENVIRONMENTAL TECHNOLOGY & INNOVATION
(2023)
Article
Engineering, Environmental
Bang Du, Xinmin Zhan, Piet N. L. Lens, Yifeng Zhang, Guangxue Wu
Summary: Efficient anaerobic digestion relies on the cooperation of different microorganisms with different metabolic pathways. This study investigated the effects of different operational modes and the addition of powdered activated carbon (PAC) on ethanol metabolic pathways. The results showed that the SBR mode and the presence of CO2 facilitated ethanol metabolism towards propionate production, while the CFR mode with extended solids retention time enriched Geobacter. Adjusting operational modes and PAC addition can modulate anaerobic ethanol metabolism and enrich Geobacter.
