Article
Engineering, Environmental
P. Y. Nguyen, Ricardo Marques, Hongmin Wang, Maria A. M. Reis, Gilda Carvalho, Adrian Oehmen
Summary: Members of the genus Tetrasphaera, potential polyphosphate accumulating organisms (PAOs), have been found to be more abundant than Accumulibacter in full-scale enhanced biological phosphorus removal (EBPR) wastewater treatment plants worldwide. Previous studies have primarily focused on the response of Accumulibacter to pH changes, while this study examines the effect of pH on a Tetrasphaera PAO enriched culture. The results show that pH has a significant impact on the P release and uptake kinetics of PAOs and that high pH levels can benefit the performance of EBPR.
Article
Environmental Sciences
Weihua Zhao, Xuejun Bi, Yongzhen Peng, Meng Bai
Summary: This paper discusses the metabolic mechanisms, process applications, community abundance, and influencing factors of phosphorus-accumulating organisms (PAOs) in wastewater treatment. It identifies novel PAOs, such as Dechloromonas and Tetrasphaera, which can remove phosphorus through different metabolic pathways. Dechloromonas can achieve simultaneous nitrogen and phosphorus removal in an anoxic environment, reducing carbon source requirements and energy consumption.
Article
Ecology
Francesca Petriglieri, Caitlin Singleton, Miriam Peces, Jette F. Petersen, Marta Nierychlo, Per H. Nielsen
Summary: Members of the genus Dechloromonas play a significant role in enhanced biological phosphorus removal systems, with the potential for polyphosphate accumulation. Seven distinct Dechloromonas species were identified in different Danish EBPR plants, each capable of accumulating polyphosphate, glycogen, and polyhydroxyalkanoates.
Article
Environmental Sciences
Hongjun Liu, Wei Zeng, Qingan Meng, Zhiwei Fan, Yongzhen Peng
Summary: This study investigated the impact of temperature changes on Tetrasphaera-PAOs and found that at lower temperatures their bioactivity was inhibited, while at higher temperatures the efficiency was very high. Temperature variation can affect the distribution of Tetrasphaera clades, which may be a main reason for EBPR performance.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Engineering, Environmental
Hongwei Sun, Xin Zhang, Feng Zhang, Hao Yang, Jianbo Lu, Shijian Ge, Xiaoqiang Li, Wei Zhang
Summary: The study demonstrates that free ammonia (FA) inhibits phosphorus release and uptake processes in enhanced biological phosphorus removal (EBPR) systems, affecting key microbial communities and Tetrasphaera being identified as the sole virtual biomarker for EBPR performance response to FA inhibition.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2021)
Article
Engineering, Environmental
Srdana Kolakovic, Elisabete B. Freitas, Maria A. M. Reis, Gilda Carvalho, Adrian Oehmen
Summary: This study investigated the relationship between the diversity of Accumulibacter and EBPR performance, revealing that changes in the community structure and conditions of Accumulibacter under different operating conditions can influence the success or failure of EBPR operation.
Article
Environmental Sciences
Hui Wang, Limin Lin, Lu Zhang, Ping Han, Feng Ju
Summary: This study investigates the effect of the nitrification inhibitor allylthiourea (ATU) on the microbiome assembly and functional potential in enhanced biological phosphorus removal (EBPR) systems. The results showed that ATU increased microbiota structural similarity and compositional convergence, and enhanced determinism in the assembly of EBPR microbiome. Additionally, ATU promoted the enrichment of functional genes involved in phosphate transport and polyphosphate synthesis and degradation.
ENVIRONMENTAL RESEARCH
(2023)
Article
Engineering, Environmental
Jianfeng Zheng, Nan Wang, Ledan Zhao, Yajing Li, Jingjie Yu, Shaopo Wang
Summary: This study explored the microbial population dynamics of Accumulibacter (Acc) at low temperature and its metabolic shift to limiting polyphosphate (Poly-P) in the enhanced biological phosphorus removal (EBPR) system. The results showed that the microbial community structure changed at low temperature, and the formation of granular sludge in the EBPR system was enhanced. Additionally, the study found that poly-P levels can affect the metabolic pathway of Accumulibacter at low temperature.
WATER SCIENCE AND TECHNOLOGY
(2022)
Article
Ecology
C. M. Singleton, F. Petriglieri, K. Wasmund, M. Nierychlo, Z. Kondrotaite, J. F. Petersen, M. Peces, M. S. Dueholm, M. Wagner, P. H. Nielsen
Summary: The bacterial genus Tetrasphaera is responsible for enhanced biological phosphorus removal (EBPR) in wastewater treatment plants. Recent analyses showed that 16S rRNA genes cannot accurately resolve the lineage of Tetrasphaera, which actually consists of several different genera within the Dermatophilaceae. This study identifies and examines 14 metagenome-assembled genomes containing full-length 16S rRNA genes from wastewater treatment plants, and reveals that the uncultured Tetrasphaera clade 3 represents two distinct genera named Ca. Phosphoribacter and Ca. Lutibacillus. Ca. Phosphoribacter is found to be the most abundant former Tetrasphaera lineage and polyphosphate accumulating organisms (PAO) in EBPR systems in Denmark and globally.
Article
Engineering, Environmental
Varun N. Srinivasan, Guangyu Li, Dongqi Wang, Nicholas B. Tooker, Zihan Dai, Annalisa Onnis-Hayden, Charles Bott, Paul Dombrowski, Peter Schauer, Ameet Pinto, April Z. Gu
Summary: This study compared the microbial ecology of CAP between a side-stream EBPR and a conventional A2O EBPR process, revealing differences in microdiversity that likely contribute to the improved performance of S2EBPR. It also identified previously uncharacterized clades of CAP and demonstrated the temporally increasing predominance of certain CAP clades during the implementation of the S2EBPR configuration in full-scale EBPR systems.
Article
Environmental Sciences
Njabulo Thela, David Ikumi, Theo Harding, Moses Basitere
Summary: This study cultured phosphorus-accumulating organisms (PAOs) in the laboratory and investigated their preference for different carbon sources and their ability to remove phosphorus from wastewater. The results showed that PAOs preferred propionate, and the concentration of PAO biomass increased when the propionate concentration in the wastewater increased.
Article
Engineering, Environmental
Seungdae Oh, Youngjun Kim
Summary: This study advanced the understanding of the diversity and interactions of PAOs and GAOs in EBPR systems using machine learning models, identifying specific species populations strongly correlated with water temperature and validating their positive association in real-scale processes.
JOURNAL OF WATER PROCESS ENGINEERING
(2021)
Article
Engineering, Environmental
Xuhan Deng, Jing Yuan, Liping Chen, Hang Chen, Chaohai Wei, Per H. Nielsen, Stefan Wuertz, Guanglei Qiu
Summary: This study systematically analyzed the occurrence and characteristics of CRISPR-Cas systems and prophages in Ca. Accumulibacter members. The results showed that 28 Ca. Accumulibacter genomes encode CRISPR-Cas systems, providing adaptive resistance to phage predation. The study also revealed high relative abundances of Ca. Accumulibacter with CRISPR-Cas systems in laboratory-scale EBPR bioreactors, indicating their specific resistance to phages.
Article
Environmental Sciences
Alexander Dorofeev, Anna Pelevina, Yuri Nikolaev, Yulia Berestovskaya, Evgeny Gruzdev, Andrey Mardanov, Nikolai Pimenov
Summary: This study investigated the substrate range of Ca. Accumulibacter by measuring its oxygen uptake rates (OUR) with 17 different organic substrates. The results showed that Ca. Accumulibacter preferred tryptone, volatile fatty acids, succinate, pyruvate, and amino acids as substrates. The possible pathways for substrate transport and metabolism by Ca. Accumulibacter were discussed using stoichiometric data and metagenomic analysis.
Article
Engineering, Environmental
Liping Chen, Gengrui Wei, Yushen Zhang, Kaiying Wang, Cenchao Wang, Xuhan Deng, Yaqian Li, Xiaojing Xie, Jinling Chen, Fu Huang, Hang Chen, Bin Zhang, Chaohai Wei, Guanglei Qiu
Summary: Previous research has shown that Ca. Accumulibacter and Tetrasphaera play cooperative roles in enhanced biological phosphorus removal (EBPR). However, the utilization of fermentation products released by Tetrasphaera and their potential effects on Ca. Accumulibacter metabolism were unknown. This study investigated the metabolic details of Ca. Accumulibacter in using fermentation products for EBPR, providing insights into their interactions.
Review
Microbiology
Hans-Curt Flemming, Eric D. van Hullebusch, Thomas R. Neu, Per H. Nielsen, Thomas Seviour, Paul Stoodley, Jost Wingender, Stefan Wuertz
Summary: In this review, the authors revisit the understanding of the biofilm matrix and discuss the diversity of its components and the novel aspects of their functional interactions. The biofilm matrix plays a crucial role in stabilizing microbial cells and fulfilling various functions. It is dynamic and influenced by physico-chemical and biological interactions as well as environmental conditions.
NATURE REVIEWS MICROBIOLOGY
(2023)
Article
Ecology
Mantas Sereika, Francesca Petriglieri, Thomas Bygh Nymann Jensen, Artur Sannikov, Morten Hoppe, Per Halkjaer Nielsen, Ian P. G. Marshall, Andreas Schramm, Mads Albertsen
Summary: Cable bacteria are centimeter-long filamentous bacteria capable of long-distance electron transfer. They are currently classified into two candidate genera: Candidatus Electronema, found in freshwater, and Candidatus Electrothrix, found in saltwater. To address the lack of complete genomic information, researchers performed Nanopore long-read and Illumina short-read shotgun sequencing, resulting in the recovery of multiple cable bacteria genomes. Phylogenomic analysis classified two circular genomes as novel species: Ca. Electronema halotolerans and Ca. Electrothrix laxa. The discovery of Ca. Electronema halotolerans in brackish-water sediment suggests its evolutionary link between marine and freshwater cable bacteria lineages.
Article
Biochemistry & Molecular Biology
Hileia K. S. Souza, Mariana Matos, Maria A. M. Reis, Jose A. Covas, Loic Hilliou
Summary: Wet biomass mastication before solvent extraction can improve the purity and thermal stability of PHA, as well as its melt rheology, thus recovering the viscoelasticity of PHA extracted from dried biomass.
Article
Respiratory System
Hien Thi Thu Nguyen, Vang Le-Quy, Son Van Ho, Jakob Holm Dalsgaard Thomsen, Malene Pontoppidan Stoico, Hoang Van Tong, Nhat-Linh Nguyen, Henrik Bygum Krarup, Son Hong Nguyen, Viet Quoc Tran, Linh Toan Nguyen, Anh Tuan Dinh-Xuan
Summary: This study aims to predict the severity of COVID-19 based on clinical and biological indicators, and identify biomarkers for prognostic assessment. The most important indicators were IL-6, ferritin, and D-dimer. Two different sets of biomarkers can be used for disease severity assessment and prognosis.
Article
Agricultural Engineering
Agnieszka Garlicka, Katarzyna Umiejewska, Per Halkjaer Nielsen, Adam Muszynski
Summary: The aim of this project was to increase methane production by combining feedstock pretreatment and co-digestion of maize silage with thickened excess sludge. Results showed that pretreatment of sludge alone increased methane production from 0.192 Nml/gVS (sludge + maize silage) to 0.220 Nml/gVS (pretreated sludge + maize silage). However, the energy balance indicated that the additional energy generated was not enough to cover the energy expenditure for the mechanical pretreatment. 16S rRNA gene amplicon sequencing revealed the composition of the microbial community, with Chloroflexi, Bacteroidota, Firmicutes, Proteobacteria, and Actinobacteriota being the most abundant bacteria phyla.
BIORESOURCE TECHNOLOGY
(2023)
Article
Environmental Sciences
V. C. F. Carvalho, J. C. Fradinho, A. Oehmen, M. A. M. Reis
Summary: The utilization of non-aerated microalgae-bacterial consortia for phototrophic biological nutrient removal (photo-BNR) has emerged as an alternative to conventional wastewater treatment. This study evaluated the long-term operation and operational parameters of a photo-BNR system to understand its limitations and performance. The results showed that light availability had a greater impact on oxygen production than CO2 concentration, and the system achieved efficient nutrient removal without internal polyhydroxyalkanoates (PHA) limitation. The photo-BNR system demonstrated a good settling capacity and the potential for aeration-free wastewater treatment.
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2023)
Article
Engineering, Environmental
Martin Hjorth Andersen, Lisette Thomsen, Mikkel Stokholm-Bjerregaard, Susan Hove Hansen, Mads Albertsen, Per Halkjaer Nielsen, Soren Eriksen
Summary: The partial nitritation/anammox process is a popular approach for removing nitrogen from sidestreams, but it requires extensive surveillance and monitoring due to its sensitivity to disturbances. In this study, we utilized online sensor data and Nanopore DNA sequencing to monitor the microbial community and detect system disturbances in two full-scale deammonification reactors over a year. DNA surveillance revealed unexpected variations in anammox bacteria, and the composition and dynamics of the surrounding community indicated causes for occasional process disturbances. Monitoring the ammonia oxidizing bacteria (AOB) and nitrite oxidizing bacteria (NOB) could potentially optimize reactor operation. The use of frequent DNA sequencing was found to be an important supplement to online sensor data for process surveillance and control.
Article
Chemistry, Multidisciplinary
Eliana C. Guarda, Eunice Costa, Catia Gil, Catarina L. Amorim, Claudia F. Galinha, Anouk F. Duque, Paula M. L. Castro, Maria A. M. Reis
Summary: Traditional tools for controlling and monitoring biological systems are often offline and time-consuming, leading to ineffective and delayed responses. This study evaluated the feasibility of using two-dimensional fluorescence spectroscopy as a real-time and non-destructive procedure to monitor acidogenic fermentation in a granular sludge reactor. The results showed that fluorescence spectroscopy combined with mathematical analysis could accurately predict fermentation products and soluble protein concentrations in the effluent.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2023)
Article
Biochemistry & Molecular Biology
Kayo Santana Barros, Monica Carvalheira, Bruno Costa Marreiros, Maria Ascensao M. Reis, Joao Goulao Crespo, Valentin Perez-Herranz, Svetlozar Velizarov
Summary: For the production of polyhydroxyalkanoates (PHA) using nitrogen-rich feedstocks, the typical strategy of restricting cell growth by nitrogen limitation is not applicable. In this study, Donnan dialysis was evaluated as an alternative method to remove excess nitrogen ions by separating ammonium ions from volatile fatty acids in the media. The use of Fumasep and Ralex membranes showed better performance in terms of ammonium extraction compared to Ionsep.
Article
Engineering, Environmental
P. Y. Nguyen, Ricardo Marques, Hongmin Wang, Maria A. M. Reis, Gilda Carvalho, Adrian Oehmen
Summary: Members of the genus Tetrasphaera, potential polyphosphate accumulating organisms (PAOs), have been found to be more abundant than Accumulibacter in full-scale enhanced biological phosphorus removal (EBPR) wastewater treatment plants worldwide. Previous studies have primarily focused on the response of Accumulibacter to pH changes, while this study examines the effect of pH on a Tetrasphaera PAO enriched culture. The results show that pH has a significant impact on the P release and uptake kinetics of PAOs and that high pH levels can benefit the performance of EBPR.
Article
Engineering, Environmental
Congcong Zhang, Albert Guisasola, Adrian Oehmen, Juan Antonio Baeza
Summary: This study evaluates the effects of incorporating a side-stream sludge fermenter (SSSF) into an anaerobic/anoxic/aerobic (A2O) configuration for P/N/COD removal under a limited influent COD condition. The results show that the S2EBPR configuration improves P removal but also increases P-release, leading to higher effluent P concentration.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Engineering, Environmental
Marie Riisgaard-Jensen, Giulia Dottorini, Marta Nierychlo, Per Halkjaer Nielsen
Summary: The immigration of bacteria in influent wastewater has a strong impact on the microbial community of activated sludge in wastewater treatment plants. The use of primary settlers can selectively increase or reduce the abundance of certain bacteria. The process of primary settling changes the microbial community of influent wastewater and can be a candidate for upstream control to optimize the assembly of microbial communities in activated sludge.
Review
Engineering, Environmental
Jianyuan Zhen, Adrian Oehmen, Wei Wei, Shou-Qing Ni, Bing-Jie Ni
Summary: The recently proposed GAOs-driven EPDA process shows promise as an alternative method for supplying NO2- to anammox bacteria without external carbon source addition. This process demonstrates superior nitrogen elimination efficiency, cost-effectiveness, and operational stability in low C/N wastewater treatment, while also mitigating greenhouse gas releases. Future research should focus on balancing the competitiveness between functional consortia and addressing the effects of adverse conditions on nutrient removal performance in the EPDA-based processes.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Biotechnology & Applied Microbiology
Maarten D. Verhoeven, Per H. Nielsen, Morten K. D. Dueholm
Summary: The researchers introduced an experimental setup, combining 16S rRNA gene amplicon sequencing with plating of dispersed activated sludge bacteria, to rapidly identify the growth conditions that allow for the isolation of key microbial species in activated sludge. They found that agarose plates supplemented with various carbon sources support the growth of many previously uncultivated activated sludge bacteria.
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
(2023)
Article
Engineering, Environmental
A. Margarida Teixeira, Ivone Vaz-Moreira, David Calderon-Franco, David Weissbrodt, Sabina Purkrtova, Stanislav Gajdos, Giulia Dottorini, Per Halkjaer Nielsen, Leron Khalifa, Eddie Cytryn, Jan Bartacek, Celia M. Manaia
Summary: Urban wastewater treatment plants (UWTPs) are crucial for reducing pollutant load and protecting water bodies, but they also emit antibiotic resistant bacteria and resistance genes, which have impacts on downstream environments. This study tested a set of biomarkers for antibiotic resistance monitoring and found that qPCR can be a cost-effective and technically accessible approach for monitoring wastewater and downstream environments.
Article
Engineering, Environmental
Rong-Gui Zhu, Chang-Gui Pan, Feng-Jiao Peng, Chao-Yang Zhou, Jun-Jie Hu, Kefu Yu
Summary: This comprehensive survey investigated the occurrence, bioaccumulation, and trophic magnification of parabens and their metabolite 4-HB in a marine food web. Results showed that parabens were the predominant pollutants in marine organisms, with significant bioaccumulation from sediments. The estimated trophic magnification factor indicated biomagnification for MeP and trophic dilution for 4-HB. Overall, the risks for humans consuming marine organisms were found to be low.
Article
Engineering, Environmental
Andres F. Torres-Franco, Deborah Leroy-Freitas, Cristina Martinez-Fraile, Elisa Rodriguez, Pedro A. Garcia-Encina, Raul Munoz
Summary: Anaerobic and microalgae-based technologies have emerged as sustainable alternatives for municipal wastewater treatment. However, the presence of viruses in the treated wastewater is a major concern for reuse applications. This study assessed the ability of these technologies to reduce viruses during secondary wastewater treatment. The results showed that all technologies were effective in reducing the concentration of viruses, with microalgae-based treatment exhibiting the highest potential for reducing the disinfection requirements of treated wastewater.
Article
Engineering, Environmental
Young Gwang Kim, Sae Yun Kwon, Spencer J. Washburn, Scott C. Brooks, Ji Won Yoon, Lucien Besnard
Summary: The study uses Hg isotope ratios to identify the sources and exposure pathways of mercury in bivalves, finding that dissolved Hg phases in the water column are the primary source and exposure pathway to bivalves. This provides new insights into using bivalves as bioindicators for sediment quality monitoring.
Article
Engineering, Environmental
Hui Geng, Ying Xu, Rui Liu, Dianhai Yang, Xiaohu Dai
Summary: This study investigates the effect of cation exchange resin (CER) on the sequential recovery of hydrogen and methane from anaerobic digestion (AD) and the corresponding mechanisms. The results show that CER can simultaneously enhance the production of hydrogen and methane by promoting the solubilisation, hydrolysis, and acidification of organic matter. Additionally, CER facilitates effective contact between bacteria and organic particulates and reduces the energy barrier for mass transfer during methane production. The study also reveals changes in the microbial community structure and metagenomics during the AD process.
Article
Engineering, Environmental
Xiaojing Lin, Zhan Jin, Shunfeng Jiang, Zhiquan Wang, Suqing Wu, Ke Bei, Min Zhao, Xiangyong Zheng
Summary: Dehumidification combined with addition of absorbent resin supplement (ARS) was used to achieve rapid evaporation of non-pretreated urine, resulting in high water evaporation efficiency and nutrient recovery.
Article
Engineering, Environmental
Yangli Che, Chaoran Lin, Shen Li, Jiao Liu, Longhai Zhu, Shilei Yu, Nan Wang, Haoshuai Li, Mutai Bao, Yang Zhou, Tonghao Si, Rui Bao
Summary: Hydrodynamic processes play a crucial role in the transmission of sediments, microbial assembly, and organic carbon redistribution in the ocean. Through experiments and analysis, we found that hydrodynamics shape the assembly of microbial communities and control the redistribution of different sourced organic carbon, thereby influencing microbial-mediated biogeochemical transformation.
Article
Engineering, Environmental
Chao Chen, Yu Yang, Nigel J. D. Graham, Zhenyu Li, Xingtao Yang, Zhining Wang, Nadia Farhat, Johannes S. Vrouwenvelder, Li -an Hou
Summary: The fouling of seawater reverse osmosis membranes is a persistent challenge in desalination. This study monitored the operational performance of a desalination plant for 7 years and the fouling development in different areas of membrane modules. The findings showed that operational performance declined over time and fouling mainly occurred at the feed side of the modules, with the highest microbial diversity. Keystone species like Chloroflexi and Planctomycetes played an important role in maintaining community structure and biofilm maturation. Polysaccharides, soluble microbial products, marine humic acid-like substances, and inorganic substances contributed to fouling. Overall, biofouling had a significant impact on membrane fouling after 7 years of operation.
Article
Engineering, Environmental
Dan Li, Jieyi Sun, Yibo Fu, Wentao Hong, Heli Wang, Qian Yang, Junhong Wu, Sen Yang, Jianhui Xu, Yunfei Zhang, Yirong Deng, Yin Zhong, Ping'an Peng
Summary: Sulfidation-oxidation treatment of magnetite (Fe3O4) enhances the production of dark center dot OH, which can efficiently degrade dissolved organic matter (DOM) and accelerate carbon cycling.
Article
Engineering, Environmental
Cheng Yu, Kaijun Wang, Kaiyuan Zhang, Ruiyang Liu, Pingping Zheng
Summary: This study implemented a microaerobic-aerobic configuration in a full-scale municipal wastewater treatment facility and investigated the effects on sludge characteristics, pollutant removal, microbial community, and granulation mechanisms. The results showed successful transition from flocculent-activated sludge to well-defined AGS after two months of operation. The primary pathways for pollutant removal were simultaneous nitrification, denitrification, and phosphorus removal. Moreover, the incorporation of internal separators induced shifts in the flow pattern, which promoted granulation.
Article
Engineering, Environmental
Zhe Zhang, Shaoyang Hu, Guangrong Sun, Wei Wang
Summary: Halogenated aromatic disinfection byproducts (DBPs), such as halogenated phenols, have garnered widespread attention due to their high toxicity and prevalence. This study reports on the analysis, occurrence, and cytotoxicity of a group of emerging halogenated aromatic DBPs, known as halogenated polyhydroxyphenols (HPPs), in drinking water.
Article
Engineering, Environmental
Shengyue Chen, Jinliang Huang, Peng Wang, Xi Tang, Zhenyu Zhang
Summary: Accurate prediction of river water quality is crucial for sustainable water management. This study introduces wavelet analysis and transfer learning techniques to assist LSTM modeling, proposing a newly coupled modeling approach that improves short-term prediction of river water quality.
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.
Article
Engineering, Environmental
Wanfa Wang, Si-Liang Li, Jun Zhong, Yuanbi Yi, Fujun Yue, Zenglei Han, Qixin Wu, Ding He, Cong-Qiang Liu
Summary: This study compares the carbon biogeochemical processes in karst and non-karst regions within large thermal stratified river-reservoir systems. The results demonstrate that karst reservoirs have a reduced potential for carbon emissions and highlight the importance of considering geologic settings to improve accuracy in regional and global CO2 emission estimates.
Article
Engineering, Environmental
Chunxia Jiang, Zelong Zhao, Dong Zhu, Xiong Pan, Yuyi Yang
Summary: This study analyzed the occurrence and distribution of antibiotic resistance genes (ARGs) in different environmental media of the Yangtze River using metagenomics. Core resistome dominated by multidrug resistance genes was found in all samples, while rare resistome dominated by various resistance genes was more prevalent in plasmids. Specific bacteria were identified as hosts for both core and rare resistomes, with high clinical concern ARGs found in the rare resistome. Particle-associated environment provided the most ideal conditions for resistome hosts. This study provided insights into the genetic locations of ARGs and the community assembly mechanisms of ARG hosts in freshwater environments.
Article
Engineering, Environmental
Yu Zhang, Yongtao He, Linchun Jia, Lei Xu, Zheng Wang, Yueling He, Ling Xiong, Xumeng Lin, Hong Chen, Gang Xue
Summary: By synergizing organic carbon source, thiosulfate, and zero-valent iron, efficient mixotrophic denitrification of oligotrophic secondary effluent can be achieved. Thiosulfate plays a vital role in promoting TN removal efficiency, while corrosion of Fe0 releases OH- to neutralize H+ from thiosulfate-driven denitrification, creating a suitable environment for denitrification. The coordination of thiosulfate and Fe0 maintains the dominance of Thiobacillus for denitrification.