Article
Environmental Sciences
Zhen Wang, Xueming Chen, He-Ping Zhao
Summary: This study investigated the interactions between chromate, selenate, and sulfate in a methane-based membrane biofilm reactor using a modified biofilm model. Optimized operational conditions in a two-stage MBfR system showed promise in treating wastewaters impacted by CrO42- and SeO42-, while maintaining high-efficiency CrO42- removal and low-level SO42- reduction in a single MBfR with appropriate biofilm thickness and influent dissolved oxygen concentrations.
ENVIRONMENT INTERNATIONAL
(2022)
Article
Environmental Sciences
Rongfen Chen, Yan Zhou
Summary: This study demonstrated a microbial activity driven oxygen influx across a microporous hollow fibre membrane by tracking changes in volume and gas composition of entrapped air supply. The results showed that active biofilm in membrane aerated biofilm reactor can effectively uptake oxygen, potentially leading to greater energy savings in some applications.
ENVIRONMENTAL RESEARCH
(2021)
Article
Engineering, Environmental
Yulu Wang, Chun-Yu Lai, Mengxiong Wu, Xuanyu Lu, Shihu Hu, Zhiguo Yuan, Jianhua Guo
Summary: This study showed that increasing copper concentration significantly enhanced the perchlorate reduction rate in a methane-based membrane biofilm reactor, as well as promoted methane oxidation and perchlorate reduction rates through adjusting the abundance of functional genes. A higher copper concentration also increased microbial community diversity and facilitated the synergistic association between methanotrophs and perchlorate reducers.
JOURNAL OF HAZARDOUS MATERIALS
(2022)
Review
Agricultural Engineering
Zhouyan Li, Lehui Ren, Yiwen Qiao, Xuesong Li, Junjian Zheng, Jinxing Ma, Zhiwei Wang
Summary: The membrane biofilm reactor (MBfR) technology has emerged as an effective method for removing micropollutants (MPs) from water and wastewater, with advancements in fundamentals, removal performance, and microbial communities. This review consolidates the recent progress in MBfR technology and highlights the importance of microbial communities in achieving cost-effective elimination of MPs.
BIORESOURCE TECHNOLOGY
(2022)
Article
Environmental Sciences
Li He, Qi Yang, Yu Zhong, Fubing Yao, Bo Wu, Kunjie Hou, Zhoujie Pi, Dongbo Wang, Xiaoming Li
Summary: The electro-assisted autohydrogenotrophic reduction of perchlorate was successfully achieved using a dual-chamber biofilm-electrode reactor, with controlled pH and in-situ hydrogen generation. High-throughput sequencing revealed changes in microbial community composition with increasing perchlorate concentration.
Article
Environmental Sciences
Beibei Wu, Qingqing Ren, Libo Xia, Ying Liu, Xiaocai Cui, Anqi Dai, Ting Wei, Yun Zhou
Summary: System pH was found to be crucial in the biofilm-based wastewater treatment system. This study investigated the effects of pH on pollutant removal, microbial niches succession, and antibiotic resistance genes (ARGs) accumulation. The results showed that a neutral pH achieved the highest biofilm concentration and living cells, resulting in the highest pollutant removal rates. Microbial communities under acidic conditions were significantly different compared to other conditions. The study also found a positive relationship between ARG accumulation and biofilm-attached linear alkylbenzene sulfonate (LAS). The relatively low levels of ARGs under neutral conditions suggested that pH control can be an effective strategy to inhibit ARG dissemination and proliferation in the system.
ENVIRONMENTAL RESEARCH
(2023)
Article
Agricultural Engineering
Jiehui Ren, Wen Cheng, Meng Jiao, Tian Wan, Min Wang, Dong Li
Summary: The study indicated that suitable aeration rates in a laboratory-scale aerobic fluidized bed biofilm reactor can enhance the oxygen mass transfer process and microbial community structure, leading to improved efficiency in municipal wastewater treatment.
BIORESOURCE TECHNOLOGY
(2021)
Article
Agricultural Engineering
Philipp Bunse, Laura Orschler, Annika Vera Pidde, Susanne Lackner
Summary: This study examined the impact of scouring on Membrane Aerated Biofilm Reactors (MABRs) in treating municipal wastewater. Scouring was induced by bubbling dinitrogen gas through the reactor at low and high frequencies. The results showed that low nitrogen surface loads achieved almost complete ammonium removal, while high-frequency scouring resulted in less total nitrogen removal compared to low-frequency scouring. Varying the scouring strategy was found to be a potential control mechanism for MABR operation and helped to reach specific treatment targets.
BIORESOURCE TECHNOLOGY
(2023)
Article
Biotechnology & Applied Microbiology
Masumi Kobayashi, Ryosei Agari, Yunje Kigo, Akihiko Terada
Summary: A composite membrane with high oxygen permeability and low vapor permeability was developed for a membrane-aerated biofilm reactor (MABR), providing effective oxygen supply and high carbon removal rate. The PS composite membrane showed better performance in oxygen transfer and biofilm formation compared to the PU composite membrane, leading to superior operation of the MABR.
BIOCHEMICAL ENGINEERING JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
Nan Liu, Ying-ying Li, Du-juan Ouyang, Chang-yong Zou, Wei Li, Ji-hong Zhao, Ji-xiang Li, Wen-juan Wang, Ja-jun Hu
Summary: A high reduction rate integrated electrobiofilm reduction system was developed to study the dynamic changes of microbial communities during the reduction of EDTA-Fe-II-NO and EDTA-Fe-III. Results showed better performance in substrate shock loading resistance and higher microbial diversities compared to conventional systems. High-throughput sequencing analysis identified dominant genera and bacterial strains playing key roles in the reduction processes.
Article
Engineering, Environmental
Liuliu Li, Baogang Zhang, Lei Li, Alistair G. L. Borthwick
Summary: The study demonstrated the feasibility of using elemental sulfur as an electron donor to support selenium bioreduction. Involvement of Thiobacillus, Desulfurivibrio, and Sulfuricurvum bacteria indicated coupling of Se(VI) reduction with S(0) oxidation, showing microbial synergy in the process.
JOURNAL OF HAZARDOUS MATERIALS
(2022)
Article
Agricultural Engineering
Yale Deng, Yunjie Ruan, Mohammad J. Taherzadeh, Jishuang Chen, Wanhe Qi, Dedong Kong, Bin Ma, Xiangyang Xu, Huifeng Lu
Summary: The study found that increasing bamboo powder content in the carrier reduces carbon availability and has a negative impact on nitrate removal efficiency, but improves ammonia removal rate. Different carrier formulations can affect microbial compositions, with high bamboo powder content decreasing relative abundance of denitrifiers and increasing that of nitrifiers.
BIORESOURCE TECHNOLOGY
(2021)
Article
Environmental Sciences
Wael Alrashed, Rashmi Chandra, Timothy Abbott, Hyung-Sool Lee
Summary: This study assessed the effectiveness of methane-based membrane biofilm reactors (MBfRs) for nitrite removal in dilute wastewater. The results showed that high nitrite removals can be achieved at certain methane pressures and hydraulic retention times, with low dissolved methane concentrations in treated effluent.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Engineering, Environmental
Peng Zheng, Yan Li, Qiang Chi, Youpeng Cheng, Xinbai Jiang, Dan Chen, Yang Mu, Jinyou Shen
Summary: The study demonstrated the effective removal of pyridine-contaminated wastewater using bubble-free aeration membrane biofilm reactor (MABR) and highlighted its potential in treating recalcitrant pollutants. The results showed that high pyridine loading thickened the biofilm but did not cause detachment, and enhanced the metabolic efficiency of degradation pathways. The identified functional genes were mainly associated with Pseudomonas and Delftia, indicating their potential role in pyridine biodegradation.
JOURNAL OF HAZARDOUS MATERIALS
(2022)
Article
Agricultural Engineering
Xiaomei Zheng, Wenjing Zhou, Bolin Min, Yuanyuan Zhou, Li Xie
Summary: A novel horizontal rotary bioreactor was developed for upgrading biogas from coke oven gas at extremethermophilic condition. The introduction of CO decreased the outlet methane content from 80% to 50% due to insufficient H2. This hindrance was overcome by increasing the proportion of incoming hydrogen, coupled with a prolonged gas retention time from 24 to 72 h, leading to a restoration of methane content to 91.6%. Notably, CO and CO2 exhibited a competitive relationship to hydrogen, which was determined by their contents. The substitution of Methanothermobacter for Methanobacterium as the dominant genus was observed at 70 degrees C, with relative abundance exceeding 98%. Incorporation of CO increased bacteria diversity and fostered a syntrophic relationship between the bacterial community and M. thermautotrophicus. This study provides both theoretical basis and practical support for biogas upgrading from coke oven gas using a biofilm reactor, thus aiding its future industrialization prospects.
BIORESOURCE TECHNOLOGY
(2023)
Article
Microbiology
Simon J. J. McIlroy, Andy O. O. Leu, Xueqin Zhang, Rhys Newell, Ben J. J. Woodcroft, Zhiguo Yuan, Shihu Hu, Gene W. W. Tyson
Summary: In this study, a bio-reactor dominated by 'Candidatus Methanoperedens nitroreducens' was characterized using meta-omics and fluorescence in situ hybridization (FISH). Unexpectedly, two morphotypes of 'Ca. M. nitroreducens', coccobacilli microcolonies and planktonic rods, were found to stably co-exist. Genomically identical but distinct in gene expression profiles for carbon metabolism, motility, and cell division were observed in these morphotypes. Additionally, a third phenotype that stored carbon as polyhydroxyalkanoates was observed in some coccobacilli 'Ca. M. nitroreducens'. The phenotypic variation of 'Ca. M. nitroreducens' likely aids their survival and dispersal in sub-optimal environmental conditions.
NATURE MICROBIOLOGY
(2023)
Article
Engineering, Environmental
Zhuan Khai Lim, Tao Liu, Min Zheng, Maxime Rattier, Jurg Keller, Zhiguo Yuan, Jianhua Guo, Shihu Hu
Summary: Anaerobic membrane bioreactor (AnMBR) with membrane reciprocation as fouling control method showed a higher energy recovery and more energy-efficient performance compared to conventional biogas sparging in treating domestic wastewater. The carbon balance calculation and energy evaluation demonstrated that membrane reciprocation consumed 62% less energy (0.59 kWh/m3) than biogas sparging (1.56 kWh/m3) at the same operational conditions. With high biogas recovery and energy-efficient fouling control, a positive net energy balance (0.55-0.74 kWh/m3) was achieved, indicating the potential of AnMBR with membrane reciprocation as an energy-positive A-stage in domestic sewage treatment.
RESOURCES CONSERVATION AND RECYCLING
(2023)
Article
Environmental Sciences
Zhetai Hu, Shihu Hu, Pei-Ying Hong, Xueqin Zhang, Veljko Prodanovic, Kefeng Zhang, Liu Ye, Ana Deletic, Zhiguo Yuan, Min Zheng
Summary: Anaerobic treatment of domestic wastewater has advantages over conventional aerobic treatment in terms of lower biomass yield, lower energy demand and higher energy recovery. However, it faces issues of excessive phosphate and sulfide in effluent, as well as excess H2S and CO2 in biogas. This study proposes an electrochemical method that generates Fe2+ in the anode and hydroxide ion (OH-) and H2 in the cathode to overcome these challenges. The results show that dosing of the electrochemically generated iron significantly improves the performance of anaerobic wastewater treatment, increasing COD removal efficiency, CH4 production rate, dissolved sulfide reduction, and phosphate removal efficiency, while upgrading the quality of biogas by reducing CO2 and H2S contents.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Environmental Sciences
Veljko Prodanovic, Kefeng Zhang, Min Zheng, Shihu Hu, Pei-Ying Hong, Zhiguo Yuan, Ana Deletic
Summary: Vegetated biofiltration systems are widely used for urban stormwater and greywater treatment, but the impact of high ammonium strength wastewater on nitrification process is not well understood. A laboratory-based column study was conducted to investigate dominant nitrification mechanisms. The results showed that appropriate aerobic contact time, oxygenation and alkalinity buffering are necessary for effective nitrification.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Engineering, Environmental
Mengxiong Wu, Chun -Yu Lai, Yulu Wang, Zhiguo Yuan, Jianhua Guo
Summary: Nitrate contamination is a common problem in water environments and poses health risks. This study investigates the feasibility of using propane and butane as electron donors for nitrate reduction. The results showed that propane and butane could continuously remove nitrate under oxygen-limiting conditions, and certain microorganisms were responsible for the oxidation of these gases and the reduction of nitrate.
Review
Engineering, Environmental
Gaoyang Luo, Bin Liang, Hanlin Cui, Yuanyuan Kang, Xu Zhou, Yu Tao, Lu Lu, Lu Fan, Jianhua Guo, Aijie Wang, Shu-Hong Gao
Summary: The colonization of microorganisms on microplastic surfaces forms a plastisphere in the environment, which captures various substances. Due to its complex nature, the plastisphere may contribute to the development and spread of antibiotic resistance genes (ARGs), adding complexity to addressing the global challenges of microplastics and ARGs. This review focuses on the spread of ARGs mediated by microplastics and discusses the challenges and perspectives in determining the contribution of microplastics to antimicrobial resistance (AMR). The review also proposes a framework for assessing the AMR risks of micro/nanoplastics and biocolonizable microparticles based on biological sequencing data.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2023)
Article
Engineering, Environmental
Jiuling Li, Nur Nabilah Naina Mohamad, Keshab Sharma, Zhiguo Yuan
Summary: Establishing efficient boundary conditions is crucial for modeling heat transfer in sewers and recovering heat from wastewater. This study presents a novel approach using Fourier transform and data-driven models to determine the thickness of the soil layer and predict temperatures at the soil-layer boundary. The methodology improves the accuracy and speed of sewer heat transfer modeling.
Article
Engineering, Environmental
Zhetai Hu, Tao Liu, Zicheng Su, Jing Zhao, Jianhua Guo, Shihu Hu, Zhiguo Yuan, Min Zheng
Summary: Acidic partial nitritation (PN) is a stable method for wastewater treatment that can achieve nitrite accumulation and ammonium reduction. However, directly applying anaerobic ammonium oxidation (anammox) to treat acid PN effluent is problematic. This study demonstrated the adaptation of anammox to acidic pH in a moving bed biofilm reactor (MBBR), achieving high nitrogen removal efficiency. The presence of biofilm plays a critical role in protecting anammox bacteria in acidic environments.
Article
Engineering, Environmental
Joshua Frank, Xueqin Zhang, Esteban Marcellin, Zhiguo Yuan, Shihu Hu
Summary: Nitrate-dependent anaerobic methane oxidation is a microbial process that has ecological significance for global methane mitigation and application potential for wastewater treatment. This study investigated the physiological responses of a freshwater consortium dominated by 'Candidatus Methanoperedens nitroreducens' to different salinities. The results showed that the target organism had higher tolerance to high salinity stress and that the activities of nitrate reduction and methane oxidation were significantly affected by salt stress. The study also identified a new syntrophic relationship between 'Ca. M. nitroreducens' and denitrifying populations under marine salinity conditions. The findings have important implications for the ecological distribution of the nitrate-dependent AOM process in marine environments and the potential of this biotechnological process for the treatment of high-salinity industrial wastewater.
Article
Multidisciplinary Sciences
Zhetai Hu, Lanqing Li, Xiaotong Cen, Min Zheng, Shihu Hu, Xiuheng Wang, Yarong Song, Kangning Xu, Zhiguo Yuan
Summary: Integrated urban water management is an effective approach for managing urban water resources, which utilizes integrated technological solutions to achieve system-wide benefits. Research has shown that the process of producing iron salts can improve wastewater treatment in urban water systems and simultaneously recover high-quality bioenergy.
NATURE COMMUNICATIONS
(2023)
Article
Multidisciplinary Sciences
Xueqin Zhang, Georgina H. Joyce, Andy O. Leu, Jing Zhao, Hesamoddin Rabiee, Bernardino Virdis, Gene W. Tyson, Zhiguo Yuan, Simon J. Mcilroy, Shihu Hu
Summary: Anaerobic methanotrophic archaea (ANME) use multi-heme c-type cytochromes (MHCs) to mediate the reduction of metals and electrodes. Experimental evidence supports the involvement of these cytochromes in extracellular electron transfer (EET) from ANME to different electron sinks.
NATURE COMMUNICATIONS
(2023)
Article
Ecology
Jie Li, Tao Liu, Simon J. McIlroy, Gene W. Tyson, Jianhua Guo
Summary: Metagenomic and metatranscriptomic analyses were performed to reveal the microbial ecology of two biofilm systems that achieve high-level nitrogen removal through the coupling of anammox and n-DAMO processes in low-strength domestic sewage and high-strength sidestream wastewater. Different nitrogen loadings resulted in different combinations of anammox bacteria and anaerobic methanotrophs, and heterotrophic populations actively performed partial denitrification or DNRA using organic intermediates from methane breakdown. Additionally, two novel genomes belonging to Ca. Methylomirabilis were recovered, with one showing the capability of nitrate-dependent anaerobic methane oxidation.
ISME COMMUNICATIONS
(2023)
Article
Environmental Sciences
Lingfeng Wang, Shuang Qiu, Weican Shi, Jianhua Guo, Shijian Ge
Summary: Light energy is an influential parameter in microalgal-bacterial consortium systems, but its effects on denitrifying bacteria are unclear. This study investigated the variations in denitrification, microbial metabolism, sludge characteristics, and settleability under different light energy density conditions. Results showed that light energy decreased denitrification rate and led to the accumulation of denitrifying intermediates. Light energy also affected electron behavior, denitrifying enzyme activities, and sludge extracellular polymeric substance characteristics. These findings improve our understanding of denitrifiers activities and their response to short-term light energy, which can contribute to the development of sustainable wastewater treatment approaches.
Article
Environmental Sciences
Jiexi Zhong, Yunus Ahmed, Zhigang Yu, Jochen F. Mueller, Jianhua Guo
Summary: The prevalence of micropollutants and antibiotic resistance in aquatic environments has raised concerns. Conventional wastewater treatment processes have limited efficiency in removing these contaminants. This study combines urea-based graphitic carbon nitride with peroxymonosulfate to develop a one-stop photocatalytic process for the simultaneous removal of micropollutants, antibiotic-resistant bacteria, and antibiotic resistance genes. The system showed high removal efficiency and destruction of antibiotic resistance genes.
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.