Article
Biotechnology & Applied Microbiology
Shengqiong Fang, Xiaoyi Huang, Shuangling Xie, Jiale Du, Jianlong Zhu, Kai Wang, Qinglin Zhuang, Xuan Huang
Summary: A novel biochar-loaded nano-zerovalent iron composite (nZVI@CMBC) was developed and applied for the removal of hexavalent chromium in wastewater. The results showed that the nZVI@CMBC composite had a high removal efficiency of Cr(VI) under acidic conditions, with a value of 124.12 mg g(-1).
FRONTIERS IN BIOENGINEERING AND BIOTECHNOLOGY
(2022)
Article
Biochemistry & Molecular Biology
Vedrana Prorok, Dejan Movrin, Natasa Lukic, Svetlana Popovic
Summary: This paper presents an analysis of the fouling of a ceramic membrane by a mixture containing high concentrations of humic acid and colloidal silica during cross-flow ultrafiltration under various operating conditions. The experiments showed that colloidal silica exacerbates fouling and results in lower fluxes compared to the humic acid feed water. However, under certain conditions, lower concentrations of humic acid can lead to reduced fouling and higher fluxes.
Article
Engineering, Environmental
Yanni Xi, Yangtao Wu, Yanfen Liu, Tanghuan Xie, Huinian Liu, Zhu Su, Yicai Huanga, Chang Zhang, Xingzhong Yuan, Xin Li
Summary: The study demonstrates the successful synthesis of sulfidated nanoscale zerovalent iron@extracellular polymeric substances (SnZVI@EPS), which exhibit superior performance in the removal and recovery of carcinogenic hexavalent chromium (Cr(VI)) compared to traditional SnZVI. The SnZVI@EPS has a larger specific surface area and better environmental friendliness, making it a promising material for Cr(VI) remediation.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Engineering, Environmental
Yanyan Zhang, Pinar Ozcer, Subhasis Ghoshal
Summary: The sulfidation of nanoscale zerovalent iron (S-nZVI) enhances the degradation efficiency of various chlorinated hydrocarbons (CHCs) in groundwater, with the most significant improvement observed for chlorinated ethenes. Under electron limited conditions, S-nZVI enables either higher or comparable maximum degradation quantity for all CHCs investigated, indicating its promise for remediating groundwater contaminated by CHC mixtures. Sulfidation suppresses the generation of partially dechlorinated products and favors degradation pathways leading to non-chlorinated benign products, providing valuable insight for the assessment of S-nZVI applicability and benefits in CHC remediation.
Article
Biochemistry & Molecular Biology
Hui Zou, Ying Long, Liguo Shen, Yiming He, Meijia Zhang, Hongjun Lin
Summary: This study investigated the influence of Ca2+ on HA fouling and demonstrated the potential of Ca2+ addition in mitigating fouling in the coagulation-ultrafiltration process. It was found that increasing Ca2+ concentration led to an increase in filtration flux and a reduction in hydraulic filtration resistance. The effects of Ca2+ addition varied for different resistance components, with a decrease in internal blocking and concentration polarization resistance, but an increase in membrane surface deposit resistance. The main reason for the decreased filtration resistance was the enlarged particle size caused by the Ca2+ bridging effect.
Article
Environmental Sciences
Mariam Ouda, Abdul Hai, Rambabu Krishnamoorthy, Bharath Govindan, Israa Othman, Cheng Chin Kui, Myong Yong Choi, Shadi W. Hasan, Fawzi Banat
Summary: By incorporating iron oxide functionalized halloysite nanoclay (Fe-HNC) nanocomposites into polyethersulfone (PES) membranes, the filtration performance, antifouling ability, and fouling removal efficiency of the membranes can be significantly improved.
ENVIRONMENTAL RESEARCH
(2022)
Article
Polymer Science
Sri Mulyati, Sri Aprilia, Syawaliah Muchtar, Yanna Syamsuddin, Cut Meurah Rosnelly, Muhammad Roil Bilad, Shafirah Samsuri, Noor Maizura Ismail
Summary: The potential use of tannic acid as an additive for polyvinylidene difluoride membrane was investigated. The results showed that the addition of tannic acid improved the membrane properties, leading to increased water flux and improved fouling resistance.
Article
Chemistry, Physical
Roman Solovov, Verbina Orlichenia, Boris Ershov
Summary: Zerovalent iron nanoparticles with spherical shape and narrow size distribution were prepared by photochemical reduction of iron(III) in isopropyl alcohol.
JOURNAL OF MOLECULAR LIQUIDS
(2022)
Article
Engineering, Environmental
Payel Singh, Prabir Pal, Priyanka Mondal, Govindachetty Saravanan, Penumaka Nagababu, Swachchha Majumdar, Nitin Labhsetwar, Subhamoy Bhowmick
Summary: Sulphur modified nano zerovalent iron (S?nZVI) has shown high efficiency in removing inorganic arsenic from water, especially under acidic conditions. The addition of FeS on the surface of nZVI can significantly alter the sequestration mechanism of arsenic, leading to enhanced removal efficiency in contaminated water.
CHEMICAL ENGINEERING JOURNAL
(2021)
Article
Environmental Sciences
Jin Zhang, Hao Yu, Weijian Xu, Hongyu Shi, Xiaohong Hu, Jiang Xu, Liping Lou
Summary: Sulfidized nanoscale zerovalent iron (S-nZVI) is a promising material for degrading halogenated contaminants. However, its easy aggregation limits its application for in-situ groundwater remediation. Therefore, S-nZVI was decorated onto modified biochar (mBC) to enhance dispersity and reactivity with florfenicol (FF), resulting in significantly higher removal rates compared to S-nZVI alone.
ENVIRONMENTAL RESEARCH
(2023)
Article
Engineering, Environmental
Dagmar Olafsdottir, Bing Wu
Summary: The study found that humic acid can accelerate alginate fouling under both dead-end and crossflow conditions with different filtration mechanisms. Intermittent relaxation during crossflow can alleviate medium viscosity alginate fouling. High temperature clean water flushing is the most effective way to maintain membrane performance.
JOURNAL OF WATER PROCESS ENGINEERING
(2021)
Article
Environmental Sciences
Liangfeng Duan, Yinshun Dai, Lijiao Shi, Yuwei Wei, Qi Xiu, Shiwen Sun, Xiaodong Zhang, Shan Zhao
Summary: Nanoscale zero-valent iron (nZVI) is widely used for field remediation and can be sulfidated with sulfide or sulfate-reducing bacteria to enhance its performance. The presence of humic acid (HA) affects the sulfidation process and the properties of the sulfidated nZVI (S-nZVI). This study reveals that pre-added HA inhibits the removal of Cr(VI) by S-nZVI, while post-added HA enhances the removal at specific concentrations. The presence of HA can impact the performance of S-nZVI in subsurface contaminant remediation.
Article
Engineering, Environmental
Chang-Long Feng, Cheng Liu, Meng-Yao Yu, Shi-Qi Chen, Tariq Mehmood
Summary: Ultrafiltration coupled with humic acid complexation is an effective strategy for removing manganese from groundwater. The maximum removal efficiency can reach over 90% at a certain C/Mn molar ratio. The removal of Mn(II) is influenced by transmembrane pressure, solution pH, and coexisting cations. The UF membrane effectively rejects the macromolecular complexes formed by the complexation of Mn(II) and humic acid.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2022)
Article
Engineering, Environmental
Jinlong Wang, Xiaobin Tang, Yuyao Liu, Binghan Xie, Guibai Li, Heng Liang
Summary: The coupling of vermifiltration (VF) and self-sustained ultrafiltration (SUF) in this study achieved effective removal of dissolved pollutants and various microorganisms, while also improving membrane flux to ensure water safety. The synergistic effects among the modified biofouling layer structure, reduction of extracellular polymeric substances, and increase of inorganics contents contributed to the improved membrane flux, with further enhancement observed with the usage of reflux.
RESOURCES CONSERVATION AND RECYCLING
(2022)
Article
Engineering, Environmental
Junmin Deng, Sunho Yoon, Mathieu Pasturel, Sungjun Bae, Khalil Hanna
Summary: This study comprehensively examines the effect of AgNPs on the reductive ability of NZVI, and finds that low doses of AgNPs decrease the reactivity of NZVI while high doses enhance it. Additionally, sulfate and humic acid are found to enhance the removal of p-NP in the NZVI-AgNP suspension.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Engineering, Environmental
Long Tian, Peng Zhou, Zhaoyang Su, Ting Liu, Nigel Graham, Tom Bond, Wenzheng Yu
Summary: This study investigated the impact of water quality parameters on nanofiltration membrane fouling and found that hydrophobic NOM, biopolymer content, and high molecular weight components play important roles in NF membrane fouling.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Environmental Sciences
Kai Zhang, Fengchen Guo, Nigel Graham, Wenzheng Yu
Summary: In this study, an active Fe(III) oxyhydroxide-Mn(IV) oxide/3D graphene oxide (GO) gel composite was successfully fabricated through a simple hydrothermal reaction. The optimized Fe-Mn/GO composites showed superior performance with removal efficiencies of over 90% for As(III) at pH 7.0 and close to 97% for As(V) at pH 5.0. After stable and continuous operation for 20 days, the effluent concentration of arsenic could be reduced to below 10 μg/l. This research is of great significance for addressing the challenges of nanoparticle aggregation, metal leaching, and insufficient removal efficiency in practical applications.
ENVIRONMENTAL POLLUTION
(2023)
Article
Green & Sustainable Science & Technology
Jinqiang Wang, Nigel Graham, Kai Sun, Liping Wen, Wenzheng Yu
Summary: The development of a PET membrane with multiple biomimetic nanochannels for the detection of fluoride and chromium (III) ions is described. The membrane was created using an asymmetric chemical etching technique and was modified with specific recognition compounds for F- and Cr3+. The method showed excellent linear relationships between current values and ion concentrations, with low detection limits of 4.10 nM for Cr3+ and 0.46 nM for F-. The accuracy and reliability of the method were compared to conventional ICP-MS analysis and showed good agreement, demonstrating its potential application for detecting a wide range of ionic contaminants.
JOURNAL OF CLEANER PRODUCTION
(2023)
Article
Engineering, Environmental
Kai Zhang, Yuanxiao Duan, Nigel Graham, Wenzheng Yu
Summary: The electrochemical chlorination of urea to CO2 and N-2 end-products, via active-chlorine-mediated oxidation under nearly neutral conditions, is an effective treatment for medium-concentrated urea-containing wastewater. A novel flow reactor integrated with three-dimensional hierarchically porous Ru/RuO2 architectures anchored on a Ti mesh was designed. The hierarchically macroporous electrode can create sufficient exposure of catalytically active sites and facilitate the microscopic mass transport and diffusion inside the active layer, thereby contributing to the increased removal efficiency of urea-N and ammonia-N.
JOURNAL OF HAZARDOUS MATERIALS
(2023)
Article
Chemistry, Physical
Kai Zhang, Yuanxiao Duan, Nigel Graham, Wenzheng Yu
Summary: In this study, we developed a hydrothermal sulfurization-acid assisted etching strategy to fabricate Mo doped NiS/Ni3S2 polymorph heterostructure with rich sulfur vacancies (Mo-NiS/Ni3S2-rich Sv). It was discovered that the S centers on the Ni3S2 side of the nickel sulfide polymorphs served as the H2-evolving sites, while the Ni sites on the Mo-NiS side facilitated the cleavage of the HO-H bond. The presence of rich Sv expedited the evolution of H* to molecular H2, leading to enhanced HER kinetics. The optimized Mo-NiS/Ni3S2-rich Sv electrocatalyst exhibited excellent HER activity and durability in alkaline solution. Understanding the synergy of polymorph heterostructure and element defect is crucial for the rational design of high-performance HER electrocatalysts.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2023)
Article
Engineering, Chemical
Long Tian, Nigel J. D. Graham, Xiangyu Tian, Ting Liu, Wenzheng Yu
Summary: Recent studies have found that graphene oxide (GO) has great potential as advanced separation membranes for water-related environmental applications. However, GO membranes often have low water permeability and stability issues. This study developed a novel approach involving intra-defect construction and cation cross-linking to prepare highly permeable and stable GO membranes for water purification. The membrane showed excellent water flux and selectivity, as well as long-term stability and pressure-resistance.
JOURNAL OF MEMBRANE SCIENCE
(2023)
Article
Engineering, Chemical
Junling Wang, Qingguang Liu, Lei Xu, Muhammad Saboor Siddique, Wenzheng Yu
Summary: Surface water supplemented with reclaimed water can effectively alleviate water shortage. An integrated CUF-NF process was used to treat reclaimed water, and the effects of water hardness and different aluminum salts on the process were studied. Results showed that water hardness had a significant impact on the CUF-NF process, affecting membrane flux, organic matter removal, and disinfection by-product formation potential. This study provides insights into the impacts of water hardness and aluminum salts on CUF-NF processes treating surface water and contributes to the formulation of hardness standards for reclaimed water.
SEPARATION AND PURIFICATION TECHNOLOGY
(2023)
Article
Nanoscience & Nanotechnology
Kai Zhang, Fengchen Guo, Nigel Graham, Wenzheng Yu
Summary: Constructing desired morphology and nanointerface is an effective approach to enhance urea splitting for hydrogen generation. In this study, a nickel/tungsten oxide Mott-Schottky heterojunction electrocatalyst with a hedgehog-like structure was fabricated for alkaline urea splitting. The Mott-Schottky nanointerfaces between nickel and tungsten oxide domains were observed, which accelerated charge transfer rate. The optimal electrode exhibited outstanding catalytic activity and reduced cell voltage when coupled with urea oxidation reaction.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Engineering, Environmental
Muhammad Saboor Siddique, Qingyun Song, Xuejun Xiong, Hasan Fareed, Nigel Graham, Wenzheng Yu
Summary: The integration of pre-treatment methods with low pressure-driven ultrafiltration has been proven effective in reducing disinfection by-products in drinking water. In this study, a low dose peroxone assisted alkaline hydrolyzed polyacrylonitrile UF-membrane system was explored for its efficiency in removing dissolved organic matter and regulated DBPs. The HPAN membrane displayed high flux recovery and comparable removal efficiency to the NF-3 membrane. Additionally, the H2O2/O3-HPAN system significantly reduced the aromatic and fluorescent content of the DOM and removed a high percentage of THMs, HAAs, and DBPs formation.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Engineering, Environmental
Jinqiang Wang, Zhaoyang Su, Nigel J. D. Graham, Hongkai Liu, Kai Sun, Wenzheng Yu
Summary: This paper focuses on the functionalization of double positively charged polyethylenimine (PEI)/Zr4+-polyamide (PA) nanofiltration (NF) membrane. The study evaluates the properties and performance of prepared PEI/Zr4+-PA NF membrane in removing aquatic contaminants and its antifouling ability. Results show that loading Zr4+ improves the hydrophilicity and removal behavior of the membrane when exposed to high concentrations of contaminants. The effectiveness of the membrane is not affected by factors such as high filtering degree and filtration cycle, and antifouling ability can be further improved by continuously loading Zr4+.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Engineering, Environmental
Lei Xu, Shian Song, Nigel J. D. Graham, Wenzheng Yu
Summary: This study investigates the interaction between O3 and amorphous alum flocs formed during flocculation at neutral pH using a conventional coagulant (alum). It was found that O3 promotes the transition of the in-situ formed alum flocs from tetrahedral Al to octahedral Al structures, facilitating the crystallization process. The involvement of surface functional groups of amorphous Al flocs in O3 catalytic oxidation enhances the performance of the subsequent dual-membrane filtration process in terms of fouling alleviation and effluent quality improvement.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Engineering, Chemical
Long Tian, Peng Zhou, Nigel Graham, Guibai Li, Wenzheng Yu
Summary: The long-term performance of graphene oxide (GO) membranes in practical water treatment conditions was investigated. Two representative GO membranes (V-GO and P-GO) with different surface properties were evaluated for their filtration performance and biofilm characteristics. The results showed that both membranes achieved sustainable water purification, with V-GO forming a highly heterogeneous and porous biofilm and P-GO forming a thin but dense structure. The microbial community analysis revealed different bacteria compositions in the biofilms of the two membranes. The findings highlight the importance of considering membrane surface properties in designing membrane systems for long-term water treatment.
JOURNAL OF MEMBRANE SCIENCE
(2023)
Article
Engineering, Chemical
Bingqian Yang, Sajid Rashid, Nigel Graham, Wenzheng Yu
Summary: This study investigates the impact of small organic molecules (SOM) on Fe(II) coagulation and reveals that they can significantly change the coagulation behavior by forming particles with distinct nanostructures. The study also demonstrates that SOM can directly influence the structure of flocs by controlling the oxidation rate of Fe(II) and indirectly interfere with the charge transfer between flocs and free Fe(II).
SEPARATION AND PURIFICATION TECHNOLOGY
(2023)
Article
Engineering, Environmental
Mengjie Liu, Nigel Graham, Lei Xu, Kai Zhang, Wenzheng Yu
Summary: Drinking water supply in rural areas is a challenging issue, and low-cost, efficient water treatment processes are needed to provide safe and affordable drinking water. This study proposes and evaluates a bubbleless aeration BAC (ABAC) process with a hollow fiber membrane (HFM) assembly, which improves dissolved oxygen (DO) throughout the filter and enhances DOM removal efficiency. Results show that ABAC significantly increases DOC removal and decreases disinfection byproduct formation compared to a comparable filter without aeration. The proposed ABAC treatment, with its various advantages, is well-suited for decentralized drinking water systems in rural areas.
Article
Engineering, Environmental
Qingyun Song, Bingqian Yang, Mengjie Liu, Shian Song, Nigel Graham, Wenzheng Yu
Summary: It was found that aging resulted in increasing crystallization of the flocs, which can play a beneficial role in activating persulfate oxidant to remove the representative organics. Furthermore, acidification was also found to further improve the removal of low MW natural organics and tetracycline. These results show that aged flocs have a high potential of reuse for re-coagulation and activation of oxidants to enhance drinking water quality.
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.