Article
Engineering, Environmental
Lisheng Wang, Xiaofeng Kang, Yanchen Liu, Xia Huang
Summary: Stable partial nitrification was achieved in MABR using control strategies based on free ammonia (FA) and free nitrous acid (FNA), with low FA concentrations suppressing nitrite oxidizing bacteria (NOB) and FNA stabilizing partial nitrification by eliminating NOB.
Article
Engineering, Environmental
Yuanjun Liu, Liang Guo, Xiaomin Ren, Yangguo Zhao, Chunji Jin, Mengchun Gao, Junyuan Ji, Zonglian She
Summary: The application of magnetic field can accelerate aerobic granulation and enhance the partial nitrification-denitrification process, leading to improved performance in terms of granulation time, removal efficiency of COD, NH4+-N, and TN, as well as the balance of dominant genera.
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
(2022)
Article
Engineering, Environmental
Lei Qin, Pinzhong Feng, Shunni Zhu, Zhongbin Xu, Zhongming Wang
Summary: In this study, the feasibility of partial complete nitrification (PCN) in removing ammonia inhibition in high ammonia nitrogen wastewater was evaluated by constructing a biological aerated filter (BAFs) coupled microalgae culture system. The results showed that proper control of PCN was beneficial for microalgae growth and lipid production. Therefore, PCN can be an effective method for treating high ammonia nitrogen wastewater and improving the utilization efficiency of microalgae.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2022)
Article
Microbiology
Edmundo Ruesga-Gutierrez, Jose Martin Ruvalcaba-Gomez, Lorena Jacqueline Gomez-Godinez, Zuami Villagran, Victor M. Gomez-Rodriguez, Darwin Heredia-Nava, Humberto Ramirez-Vega, Ramon Ignacio Arteaga-Garibay
Summary: This study demonstrated that an Allium-based phytobiotic had a significant impact on the egg laying performance and feed conversion rate of laying hens, as well as modifications in the structure of the fecal microbiota. The supplementation of phytobiotic resulted in an increase in egg production and changes in the composition of gut microbiota, suggesting potential improvements in metabolic activities that may contribute to enhanced productivity and egg quality.
Article
Environmental Sciences
Kamil Janiak, Anna Jurga, Anna Wizimirska, Stanislaw Miodonski, Mateusz Muszynski-Huhajlo, Krzysztof Ratkiewicz, Bartosz Zieba
Summary: The study demonstrates the impressive ability of nitrifiers to resist temporary inhibition by free ammonia (FA) and restore nitrification with simple remedy actions. High FA concentrations were successfully treated without long lasting adverse effects, leading to a considerable increase in nitrification rate.
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2021)
Article
Environmental Sciences
Yue Jin, Xuli Zhang, Haixiang Li, Zhicheng Wu, Wenjie Zhang
Summary: In this study, a laboratory-scale partial nitrification reactor (PN reactor) was used to treat high-ammonia-nitrogen wastewater. The upper limit of its NH4+-N conversion rate (ACR) was investigated, and its feasibility as an anammox pre-process was explored. The PN reactor was successfully activated within 10 days and reached a high ACR value of 10.24 kg N/(m3•day) with an ammonia conversion efficiency (ACE) of 61.78%. Feasibility experiments showed that using the PN reactor as a pre-process for anammox was feasible. High-throughput sequencing revealed changes in the microbial community structure and dominant phylum and genus with an increase in ACR, but the system's stability was not disrupted. The abundance of nitrosation enzymes was positively correlated with the expression of nitrification genes in the genus Nitrosomonas.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2023)
Article
Environmental Sciences
Kunming Fu, Yihao Bian, Fan Yang, Jian Xu, Fuguo Qiu
Summary: This study investigated the effect of high dissolved oxygen (DO) concentrations on partial nitrification (PN). Contrary to conventional reports, it was observed that nitrite-oxidizing bacteria (NOB) exhibited a higher affinity for DO than ammonia-oxidizing bacteria (AOB). Strategies including intermittent aeration, free ammonia (FA), and controlled sludge retention time (SRT) were employed to successfully achieve PN with high efficiency and stability. This study provides new insights into the application of PN in wastewater treatment.
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2023)
Article
Agricultural Engineering
Guangchao Si, Bing Liu, Yingrui Liu, Tao Yan, Dong Wei
Summary: The study aims to evaluate the impact of light on the functioning of a partial nitrification algal-bacterial granular bioreactor and its nitrite accumulation mechanism. The results show that light plays a vital role in promoting the removal of ammonia nitrogen, enhancing the activities of both ammonia-oxidizing bacteria and nitrite-oxidizing bacteria, and facilitating the formation of algal-bacterial granular sludge.
BIORESOURCE TECHNOLOGY
(2022)
Article
Agricultural Engineering
Hao Jiang, Pei Yang, Zhong Wang, Shang Ren, Jingang Qiu, Haoran Liang, Yongzhen Peng, Xiyao Li, Qiong Zhang
Summary: A partial nitrification sequencing batch reactor was operated to investigate NOB acclimatization in high-ammonia wastewater treatment. Findings showed that NOB adapted to a range of free ammonia concentrations by shifting dominant NOB genus from Nitrospira to Nitrolencea. Additionally, hydroxylamine addition could serve as an emergency measure to alleviate NOB acclimatization during short-term operation.
BIORESOURCE TECHNOLOGY
(2021)
Article
Microbiology
Aixia Xu, Lingling Li, Junhong Xie, Renzhi Zhang, Zhuzhu Luo, Liqun Cai, Chang Liu, Linlin Wang, Sumera Anwar, Yuji Jiang
Summary: Bacterial diversity and its functions in soil are crucial for soil health. This study investigated the effects of N fertilization on bacterial communities and soil physicochemical properties. The results showed that N fertilizer significantly altered the diversity and abundance of bacterial communities, with Proteobacteria, Actinobacteria, Acidobacteria, and Chloroflexi being the most abundant phyla. The optimal N fertilizer application rate (N105) promoted soil microbial diversity and abundance, while high N enrichment led to an increase in heterotrophic N-fixing microorganisms. The study also highlighted the importance of soil NO3-N in determining bacterial community function under different N fertilizer treatments.
Article
Engineering, Environmental
Chunhua He, Xuesong Ren, Guoqing Xu, Zhiqiang Huang, Yulan Wang, Zhenhu Hu, Wei Wang
Summary: Phenol and ammonia are common pollutants in industrial wastewaters. The study successfully started and operated a single-stage partial nitritation /anammox reactor treating phenol-ammonia wastewater, achieving total nitrogen and COD removal efficiencies of around 73.0% and 79.5%. The anammox bacteria adapted to phenol condition and remained stable activity after 60 days of operation.
WATER ENVIRONMENT RESEARCH
(2021)
Article
Environmental Sciences
Jiamin Chen, Jiawei Liang, Chenjing Li, Jihua Dai, Wenning Mai, Yongjun Wei
Summary: High ammonia concentration hinders efficient treatment of antibiotic production wastewater. In this study, an efficient AOB microbiota (named AF2) was obtained, which showed stable performance in a high-level salt environment and demonstrated great potential for future industrial wastewater treatment of APW.
Article
Agricultural Engineering
Lai Peng, Huiling Qiu, Shengjun Li, Yifeng Xu, Chuanzhou Liang, Ning Wang, Yiwen Liu, Bing-Jie Ni
Summary: The potential of using endogenous free ammonia (FA) and free nitrous acid (FNA) as nitrous oxide (N2O) mitigators in wastewater treatment was investigated. It was found that 1.5 mg HNO2-N/L FNA could virtually abolish N2O emission from the partial-nitritation (PN) sludge, while 45 mg NH3-N/L FA and 0.015 mg HNO2-N/L FNA successfully mitigated N2O production from the full-nitrification (FN) sludge. FA treatment was more economically appealing.
BIORESOURCE TECHNOLOGY
(2023)
Article
Environmental Sciences
Huaihao Xu, Yuepeng Deng, Jie Zou, Kaoming Zhang, Xiuying Li, Yunhua Yang, Shuangqiu Huang, Zhao-Qing Liu, Zhu Wang, Chun Hu
Summary: This study investigated the response of a nitrification membrane bioreactor to an elevated ammonia loading rate. Effective nitrification performance was achieved under high loading, but became inefficient when ammonia concentration increased further. The study also found an enrichment of ammonia-oxidizing bacteria with increased loading.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Engineering, Environmental
Takahiro Watari, Yoshiki Fukushima, Toru Miwa, Yuga Hirakata, Shuji Kawakami, Yoshinobu Nakamura, Masashi Hatamoto, Takashi Yamaguchi
Summary: The study demonstrated the effectiveness of microalgal-nitrifying bacteria consortia in treating ammonia with stable partial nitrification. The photo-baffled reactor created a competitive environment between Chlorella vulgaris and nitrifying bacteria, suggesting its potential as a novel partial nitrification process for post-treatment.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2021)
Article
Environmental Sciences
Fu-ang Duan, Juan Wang, Sherif Ismail, Shihwu Sung, Zhaojie Cui, Shou-Qing Ni
Summary: This study demonstrates that modified aerobic granular sludge with hydroxypropyl-beta-cyclodextrin significantly improved the removal efficiency of specific PAHs. Factors such as initial concentration, temperature, and ion concentration were found to influence the removal process.
ENVIRONMENTAL TECHNOLOGY
(2022)
Article
Environmental Sciences
Tong Zhang, Xuming Zhuang, Shakeel Ahmad, Taeho Lee, Chengbo Cao, Shou-Qing Ni
Summary: This study investigated the role of dissimilatory nitrate reduction to ammonium (DNRA) in the stability of urban river networks and marine ecosystems. The research identified a significant positive correlation between DNRA rate and sediment organic carbon, with Anaeromyxobacter as the dominant genus and both heterotrophic and autotrophic DNRA species present. It added diversity to urban freshwater river ecosystem studies and provided new insights into the biological nitrogen cycle of typical urban inland rivers in eastern China.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2022)
Review
Environmental Sciences
Hafiz Adeel Ahmad, Shakeel Ahmad, Qingjie Cui, Zhibin Wang, Haiwei Wei, Xue Chen, Shou-Qing Ni, Sherif Ismail, Hanem M. Awad, Ahmed Tawfik
Summary: Emerging pollutants, such as pharmaceuticals and plasticizers, have raised global concerns due to their low concentration and severe toxicity. Research in the past decades has focused on the environmental distribution, ecological disturbance, and removal of EPs, but systematic reviews on the degradation of different EPs by using microbes are limited. This review article highlights the importance of using different microbes to degrade EPs and emphasizes the eco-friendly approach.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Environmental Sciences
Lijuan Deng, Wenshan Guo, Huu Hao Ngo, Xinbo Zhang, Cheng Chen, Zhuo Chen, Dongle Cheng, Shou-Qing Ni, Quan Wang
Summary: This review highlights the importance of media used in attached growth MBR (AGMBR) for wastewater treatment, with conventional media enhancing pollutant removal and new media excelling in removing emerging pollutants. Additionally, media improve sludge characteristics and alleviate membrane fouling issues. Future research should focus on developing new functional media for wider spectrum pollutant removal and enhancing biogas generation in AGMBRs at pilot or full-scale levels.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Chemistry, Multidisciplinary
Yeonju Kim, Jaecheul Yu, Soyeon Jeong, Jeongmi Kim, Seongjae Park, Hyokwan Bae, Sung-Keun Rhee, Tatsuya Unno, Shou-Qing Ni, Taeho Lee
Summary: This study evaluated the effect of Ca2+ and Mg2+ augmentation on the recovery of freshwater anammox granules affected by salinity stress. The results showed that adding Ca2+ and Mg2+ at optimal concentrations increased the granules' activity and EPS production. Salinity stress did not significantly affect the microbial community in the granules. The alleviation effect of divalent cations on salinity stress might be associated with increased EPS production rather than changes to the anammox bacteria.
APPLIED SCIENCES-BASEL
(2022)
Article
Green & Sustainable Science & Technology
Muhammad Abdul Qyyum, Sherif Ismail, Shou-Qing Ni, Ihsanullah Ihsanullah, Rizwan Ahmad, Amin Khan, Ahmed Tawfik, Abdul-Sattar Nizami, Moonyong Lee
Summary: This article comprehensively evaluates recent reports on hydrogen production from wastewater and highlights fermentation as one of the most promising methods. The study found that the sequential dark/photo fermentation approach offers maximum hydrogen yield, but more pilot-scale studies are needed. Additionally, the current challenges in implementing and commercializing wastewater hydrogen production are emphasized.
JOURNAL OF CLEANER PRODUCTION
(2022)
Article
Engineering, Environmental
Xiufeng Cao, Xiaowei Cui, Meng Xie, Rui Zhao, Lei Xu, Shouqing Ni, Zhaojie Cui
Summary: Intensified phytoremediation shows great potential in remediation of complex co-contaminated soils, with different plants exhibiting varying efficiency in removing PAHs and heavy metals. Amendments and microbial agents can significantly increase the efficiency of phytoremediation.
JOURNAL OF HAZARDOUS MATERIALS
(2022)
Article
Multidisciplinary Sciences
Yuyang Xie, Xiaolin Liu, Haiwei Wei, Xue Chen, Ningji Gong, Shakeel Ahmad, Taeho Lee, Sherif Ismail, Shou-Qing Ni
Summary: Direct sewage discharge has serious and irreversible harm to the environment, especially to the river ecosystem. Sewage discharge leads to changes in the microbial community structure of the river, reducing the diversity and richness of bacteria, while increasing the gene abundance of pathogenic bacteria.
SCIENTIFIC REPORTS
(2022)
Article
Environmental Sciences
Zhibin Wang, Pengpeng Liu, Jing Zhou, Sherif Ismail, Shakeel Ahmad, Hanem M. M. Awad, Shou-Qing Ni
Summary: This study used biomagnetic effect to promote anammox process. Batch tests and long-term experiments showed that an appropriate electromagnetic field (EMF) strength can improve the nitrogen removal performance of anammox, but higher strengths can inhibit the activity of anammox bacteria. The addition of EMF with an appropriate strength greatly improved the nitrogen removal performance of granular sludge. The study also found that EMF addition can increase the relative abundance of the main anammox bacteria.
FRONTIERS IN ENVIRONMENTAL SCIENCE
(2022)
Article
Environmental Sciences
Zhibin Wang, Jinpeng Zhang, Jing Zhou, Sherif Ismail, Hafiz Adeel Ahmad, Hanem M. Awad, Ahmed Tawfik, Shou-Qing Ni
Summary: Laboratory-scale bioreactors were used to study the effect of dimethyl sulfoxide (DMSO) on the start-up, pollutant removal efficiency, and microbial community of nitrification. DMSO concentrations above 2% had a significant inhibitory effect on the nitrification process. The microbial community was significantly different at high DMSO concentrations, with key classes changing from Blastocatellia and Clostridia to Actinobacteria and Acidobacteria.
Review
Environmental Sciences
Hafiz Adeel Ahmad, Shakeel Ahmad, Linjie Gao, Zhibin Wang, Amro El-Baz, Shou-Qing Ni
Summary: Sustainable development goal 6 focuses on efficient management of water resources, wastewater treatment, and reuse of treated wastewater. Anammox and partial nitrification (PN-anammox) has been a successful side-stream wastewater treatment process, but the involvement of other nitrogen cycle bacteria is needed. Coupling anammox with PD, DAMO, and DNRA can reduce organic matter use, greenhouse gas release, and energy consumption. This review comprehensively discusses the importance and application perspective of anammox with diverse nitrate-reducing bacteria.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Engineering, Environmental
Zhibin Wang, Cuina Bu, Jianghai Dou, Sherif Ismail, Shakeel Ahmad, Daqian Qi, Haiwei Wei, Xue Chen, Taeho Lee, Ahmed Tawfik, Shou-Qing Ni
Summary: In this study, an anammox coupled DNRA system was constructed to achieve efficient nitrate to ammonia conversion under high C/N ratio environment. DNRA bacteria were enriched and accounted for 20% of total bacteria population, while a small amount of anammox bacteria were detected. This study demonstrates the reproducibility of natural processes and provides insights into enhancing nitrogen removal rates.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2022)
Article
Environmental Sciences
Zhibin Wang, Hafiz Adeel Ahmad, Zhao-Jie Teng, Meiling Sun, Sherif Ismail, Zhuangming Qiao, Shou-Qing Ni
Summary: Similar to denitrification and anammox, DNRA is widely distributed in natural ecosystems, but often underestimated or ignored in WWTPs. A study on a full-scale SNAD WWTP revealed the coexistence of ammonia oxidizing bacteria, anammox bacteria, nitrite oxidizing bacteria, denitrifying bacteria, and DNRA organisms, with a higher relative abundance of the DNRA functional gene. The unintended selection of DNRA in the SNAD process created an engineering inefficiency of nitrogen removal by utilizing carbon that should be allocated for denitrification.
Article
Environmental Sciences
Jianyuan Zhen, Yiyi Zhao, Xuefeng Yu, Wenshan Guo, Zhuangming Qiao, Sherif Ismail, Shou-Qing Ni
Summary: The combination of partial nitrification, nitrite-denitrifying phosphorus removal, and simultaneous nitrification-endogenous denitrification showed high efficiencies in COD, nitrogen, and phosphorus removal. It provided an economic and technical alternative for treating wastewater with high levels of C, N, and P, reducing costs and carbon demand.
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.
