Article
Engineering, Environmental
Victoria Griessmeier, Jan Wienhoefer, Harald Horn, Johannes Gescher
Summary: This study investigated the efficiency of nitrate elimination and microbial communities in a denitrification bed over a period of more than three years. It found that temperature and hydraulic retention time are the main factors impacting denitrification efficiency, and the simple design of denitrification beds may result in different flow paths through the reactor.
Review
Environmental Sciences
Zhen-Le Hao, Amjad Ali, Yi Ren, Jun-Feng Su, Zhao Wang
Summary: This article discusses the application of aerobic denitrification technology in nitrogen compound removal. By reviewing four theories explaining the mechanism of aerobic denitrification and summarizing the parameters affecting its efficiency, the article suggests the potential of utilizing aerobic denitrifying bacteria to improve the design of wastewater treatment facilities, providing engineers with references.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Engineering, Environmental
Hai Wang, Renrong Liu, Qian Chen, Haixin Xia, Yaohong Zhang
Summary: In this study, the composite of Chitosan-FeS @ peanut shell biochar (CFP) was applied in constructed wetlands (CWs) to treat N and Pb co-existing wastewater. The results showed that adding CFP enhanced the nitrification and denitrification intensity and increased the removal rates of NO3-, NH4+ and TN. CFP not only acted as an electron donor to drive denitrification, but also increased the abundance of Thiobacillus, Sulfurimonas and Geobacter, thus promoting N removal. Furthermore, CFP alleviated Pb stress on Acorus calamus L.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2023)
Article
Environmental Sciences
Andrea R. McEachran, Loulou C. Dickey, Chris R. Rehmann, Thomas M. Isenhart, Tyler A. Groh, Michael A. Perez, Cassandra J. Rutherford
Summary: A three-dimensional groundwater model was developed to assess nitrate removal in a saturated riparian buffer (SRB) in central Iowa. The model showed that groundwater flow was primarily one-dimensional in the buffer and three-dimensional near the distribution pipe and stream. The length of the flow path and depth were found to impact nitrate removal potential.
JOURNAL OF ENVIRONMENTAL QUALITY
(2023)
Article
Engineering, Environmental
Liuqin Huang, Junyue Luo, Linxin Li, Hongchen Jiang, Xiaoxi Sun, Jian Yang, Weiyu She, Wen Liu, Liqing Li, Allen P. Davis
Summary: Bioretention systems are environmentally friendly measures for managing urban stormwater runoff. This study investigated the fate of inorganic nitrogen (NH4+ and NO3-) in bioretention systems under different configurations and stormwater conditions. The results showed that NH4+ was efficiently converted to NO3- by ammonia-oxidizing and nitrite-oxidizing bacteria in the oxic media. However, the pathways for NO3- removal varied depending on the configuration of the bioretention columns. Vegetation improved NO3- reduction through root assimilation and enhancement of microbial activity in the rhizosphere. The presence of an organic-rich saturation zone stimulated chemolithotrophic NO3- reduction coupled with oxidation of reductive sulfur compounds, while an organic-poor saturation zone allowed for multiple oligotrophic NO3- reduction pathways. These findings emphasize the importance of considering the variation in N transformation pathways for designing bioretention systems.
Article
Engineering, Civil
Chao Gao, Jun Kong, Lvbin Zhou, Chengji Shen, Jun Wang
Summary: This study investigates the impact of macropores on freshwater-saltwater mixing and terrestrial solute transport using laboratory-scale experiments and numerical modeling. The results show that macropores modify groundwater flow dynamics, leading to larger mixing zones and increased removal of nitrate. These findings have important implications for coastal ecosystem protection and reducing nitrate fluxes.
JOURNAL OF HYDROLOGY
(2023)
Article
Chemistry, Multidisciplinary
Tran Ha Quan, Elena Gogina, Nikolay Makisha, Igor Gulshin, Elena Makisha
Summary: Wastewater treatment facilities using the activated sludge process, particularly sequenced batch reactors, are widely used worldwide. This study focused on the treatment processes in SBRs, specifically the nitrification and denitrification processes, in relation to Hoa Xuan wastewater treatment plants in Vietnam. The research found that achieving high removal efficiency of pollutants in SBRs requires a pH value close to 8.0. Furthermore, the study demonstrated that the treatment quality in SBRs met the stricter Russian Federation standards rather than the Vietnamese standards.
APPLIED SCIENCES-BASEL
(2023)
Article
Agricultural Engineering
Miao Zhang, Jing Gao, Quanlong Liu, Yajun Fan, Chenjie Zhu, Yizhong Liu, Chengda He, Jun Wu
Summary: The study investigated the effect of influent COD/NO3- ratios on partial denitrification, showing that higher ratios led to improved denitrification efficiency and nitrate removal. Microbial analysis indicated lower diversity and more concentrated microbial communities at a specific COD/NO3- ratio.
BIORESOURCE TECHNOLOGY
(2021)
Article
Geosciences, Multidisciplinary
Fangjuan Huang, Xianbiao Lin, Weifang Hu, Fang Zeng, Lei He, Kedong Yin
Summary: This study investigates the microbial nitrogen cycling processes in surface sediments of the Pearl River Estuary, revealing higher rates and gene abundance in the outer estuary. Denitrification was found to be the dominant pathway contributing to nitrate reduction in the study area, suggesting the sediment's significant role in mitigating and controlling nitrogen pollution. The study also highlights the complexity of nitrogen cycling processes in controlling the N budget in the Pearl River Estuary and improving the understanding of these processes in estuarine and coastal ecosystems.
Article
Energy & Fuels
Lin Jiang, Yan Song, Wen Zhao, Dongmei Bo, Shaobo Liu, Jiaqing Hao
Summary: This study aims to elucidate the CBM enrichment mechanism in the southern Qinshui Basin, China, and provides new insights into CBM enrichment patterns. The findings reveal a high-yield model of CBM accumulation and the primary challenges for CBM development in China. This study represents a valuable contribution toward unlocking China's CBM potential through improved geological characterization.
JOURNAL OF PETROLEUM EXPLORATION AND PRODUCTION TECHNOLOGY
(2023)
Article
Engineering, Environmental
Xin Li, Xiangzhen Li, Chaonan Li, Na Li, Ping Zou, Xiaolong Gao, Qin Cao
Summary: This study compared denitrification using different VFAs as carbon sources and found that propionate and butyrate systems had higher maximum nitrate removal rates when facing high nitrate volumetric loading rates. Microbial community analysis showed that the enrichment of denitrification bacteria in propionate and butyrate systems was faster, which helped enhance the denitrification performance. The enrichment of functional bacteria in the acetate system took longer.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Engineering, Environmental
Jiaxing Lu, Zizhang Guo, Mengting Li, Mingyu He, Jianyuan Zhen, Bing-Jie Ni, Jian Zhang
Summary: This study investigated the effect of suitable substrates on the removal of PAHs in constructed wetlands. One of the wetland systems (CW-D) achieved satisfactory and stable PAHs removal by 23.80%-31.18% compared to the control group after 120 days of operation. Microbial degradation was identified as the main PAHs removal mechanism, and the increased proportion of microbial degradation in CW-D resulted in higher PAHs removal. Root length and microbial diversity were found to be the two driving factors affecting PAHs removal. This study provides comprehensive insights into the importance of suitable substrates, as well as the related mechanism and driving factors for PAHs removal in constructed wetlands.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Environmental Sciences
Xinjie Gao, Zaizhou Xu, Yongzhen Peng, Liang Zhang, Jing Ding
Summary: This study investigated the nitrogen removal performance of AOA process at low and room temperatures. The results showed that the nitrification capacity of AOA process was recovered at low temperature and the endogenous denitrification performance was enhanced by converting the partial aerobic zone into anoxic. The activity and abundance of ammonia-oxidizing bacteria (AOB) increased at low temperature, which was the key for nitrification capacity recovery. Overall, AOA system showed the possibility of advanced nitrogen removal at low temperatures.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Agriculture, Multidisciplinary
Wangshou Zhang, Hengpeng Li, Tianyu Xia, Heng Cao
Summary: This study investigated the variabilities of nitrogen (N) removal in different types of ponds from a hilly watershed and found that ponds impacted by different land use types exhibited distinct potentials for N removal. Ponds draining tea plantations had the highest N removal rate, and the levels of dissolved oxygen and nutrient supply were responsible for the different potentials of N removal. The results suggest the need for integrated management strategies to promote N removal more efficiently.
AGRICULTURE ECOSYSTEMS & ENVIRONMENT
(2022)
Article
Environmental Sciences
Ibrahim Maamoun, Ramadan Eljamal, Osama Eljamal
Summary: This study aimed to optimize the synthesis parameters of nZVI for the removal of phosphorus (P) and nitrate (NO3-) by conducting statistical analysis and considering cost-effectiveness. The optimization of the synthesis factors improved the removal efficiency of NO3- and P by 27% and 9% respectively. The statistical analysis showed the significance of the models and linear effects of the synthesis parameters. The normal probability plots revealed the important factors for achieving higher reactivity and reduced synthesis cost.
Article
Biochemistry & Molecular Biology
Francesca M. Simonte, Andreas Doetsch, Lisete Galego, Cecilia Arraiano, Johannes Gescher
MOLECULAR MICROBIOLOGY
(2017)
Article
Biochemistry & Molecular Biology
Calum Johnston, Isabelle Mortier-Barriere, Vanessa Khemici, Patrice Polard
MOLECULAR MICROBIOLOGY
(2018)
Article
Multidisciplinary Sciences
Susanne Krause, Andreas Bremges, Philipp C. Muench, Alice C. McHardy, Johannes Gescher
SCIENTIFIC REPORTS
(2017)
Article
Biotechnology & Applied Microbiology
Laure Cuny, Daniel Pfaff, Jonas Luther, Florian Ranzinger, Peter Oedman, Johannes Gescher, Gisela Guthausen, Harald Horn, Andrea Hille-Reichel
BIOTECHNOLOGY AND BIOENGINEERING
(2019)
Article
Biotechnology & Applied Microbiology
Helge M. Dietrich, Miriam Edel, Thea Bursac, Manfred Meier, Katrin Sturm-Richter, Johannes Gescher
MICROBIAL CELL FACTORIES
(2019)
Article
Biotechnology & Applied Microbiology
Miriam Edel, Gunnar Sturm, Katrin Sturm-Richter, Michael Wagner, Julia Novion Ducassou, Yohann Coute, Harald Horn, Johannes Gescher
Summary: This study identified a new quorum-sensing mechanism in S. oneidensis, where riboflavin production and excretion trigger biofilm formation by upregulating proteins involved in the process. The findings could be utilized for developing strains that generate higher current densities in bioelectrochemical systems.
BIOTECHNOLOGY FOR BIOFUELS
(2021)
Article
Biotechnology & Applied Microbiology
Sabrina Gfrerer, Dennis Winkler, Julia Novion Ducassou, Yohann Coute, Reinhard Rachel, Johannes Gescher
Summary: This study demonstrates the existence of an S-layer protein on the cytoplasmic membrane of Candidatus Micrarchaeum harzensis A_DKE, suggesting that the ability to form an S-layer may be a common trait among Micrarchaeota. The research also provides insights into the interaction between Micrarchaeota and their host organisms, shedding light on the limited metabolic capabilities shared by several DPANN archaea.
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
(2022)
Article
Biotechnology & Applied Microbiology
Edina Klein, Janek Weiler, Michael Wagner, Minja Celikic, Christof M. Niemeyer, Harald Horn, Johannes Gescher
Summary: Aerobic granular sludge has become an increasingly popular method for wastewater treatment due to its ability to remove organic carbon, nitrogen, and phosphorus simultaneously. However, analyzing the processes and microbial population within the granules is challenging due to their microscale. In this study, a small-scale model system for aerobic granular sludge was introduced using a machine-assisted microfluidic cultivation platform. With this setup, it was possible to enrich specific microorganisms and investigate the influence of process parameters on wastewater treatment systems.
APPLIED MICROBIOLOGY AND BIOTECHNOLOGY
(2022)
Article
Microbiology
Dennis Winkler, Sabrina Gfrerer, Johannes Gescher
Summary: The physiology of acidophilic Micrarchaeota, such as Candidatus Micrarchaeum harzensis A_DKE, remains largely unknown due to the highly expressed hypothetical proteins. In this study, isocitrate dehydrogenase (MhIDH) from A_DKE was recombinantly produced and characterized, showing specific activity for NADP(+) with low affinity likely due to a proline residue in the NADP(+) binding pocket.
Article
Agricultural Engineering
Daniel Haerrer, Ahmed Elreedy, Rowayda Ali, Andrea Hille-Reichel, Johannes Gescher
Summary: This study investigated the impacts of toxic ions/acids in real fermentation-hydrolysate on the model exoelectrogenic G. sulfurreducens. Different concentrations of acetate, butyrate, propionate, Na+, and K+ were tested individually and in combination to understand their effects on planktonic growth. The study found that excess Na+ (>= 100 mM) causes inhibition that can be reduced by K+ replacement, butyrate (>= 10 mM) induces higher toxicity than propionate, and hydrolysate induces synergistic inhibition where organic constituents are more significant than Na+. The research concluded that using G. sulfurreducens in bioelectrochemical systems can effectively recover energy from fermentation-hydrolysate.
BIORESOURCE TECHNOLOGY
(2023)
Review
Biotechnology & Applied Microbiology
Edina M. M. Klein, Melanie T. T. Knoll, Johannes Gescher
Summary: Microbial electrochemical systems (MESs) are a versatile platform technology focused on power or energy production, often combined with substrate conversion and value-added compound production. This review provides a brief summary of the terminology and essential biological background of MES technology. Recent research on improvements at the biofilm-electrode interface is discussed, comparing biotic and abiotic approaches. The review concludes with future directions for increasing process efficiency in MES technology.
MICROBIAL BIOTECHNOLOGY
(2023)
Review
Microbiology
Laura-Alina Philipp, Katja Buehler, Roland Ulber, Johannes Gescher
Summary: Biofilm systems are adaptable and offer a wide range of opportunities due to their ability to optimize metabolism and adhere in continuous systems. The field of beneficial biofilms is rapidly evolving, with increasing applications being explored.
NATURE REVIEWS MICROBIOLOGY
(2023)
Article
Microbiology
Melanie Tabea Knoll, Emely Fuderer, Johannes Gescher
Summary: The utilization of a synthetic hydrogel matrix with S. oneidensis cells improves anodic processes in BES, leading to a significant increase in current density. This has the potential for higher space-time yields in industrial applications.
Article
Biotechnology & Applied Microbiology
Thea Bursac, Jeffrey A. Gralnick, Johannes Gescher
BIOTECHNOLOGY AND BIOENGINEERING
(2017)