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Niche Differentiation of Comammox Nitrospira and Canonical Nitrifiers in Riparian Wetland Ecosystems Around Taihu Lake

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SSRN 2022年

作者： He, Yanqing She, Yuecheng Qi, Xin Zhang, Hui Wang, Wei Li, Zhengkui School of the Environment Nanjing University Nanjing Jiangsu210023 China State Key Laboratory of Pollution Control and Resource Reuse Nanjing University Nanjing210023 China

Complete ammonia oxidation (Comammox) overturned our perception of ammonia oxidation and challenged the traditional two-step nitrification theory. Newly discovered comammox Nitrospira and canonical nitrifiers (AOA and AOB) collaboratively perform the oxidation of ammonia in ecosystems. However, the niche distribution of comammox Nitrospira is controversial. In our study, we explored the distribution, diversity and driving environmental factors of comammox Nitrospira in riparian wetland ecosystems around Taihu Lake. Comammox Nitrospira was detected in all 15 soil samples, with the amo A gene abundance ranging from 1.83×10 5 to 8.35×10 7 copies/g. In most soil samples, the amo A gene abundance of comammox Nitrospira was lower than that of canonical nitrifiers. High-throughput sequencing indicated that the community structure of comammox Nitrospira had both spatial and temporal heterogeneity. The comammox Nitrospira detected in our study was divided into cladeA.1 cluster and clade A.2 cluster. Comammox Nitrospira clade A.2 observed in all soil samples was more prevalent, while the clade A.1 was mainly observed in the wheat field. Nitrospira sp. and Nitrospira sp. LK70 had the highest relative abundance and might be the key species of comammox Nitrospira . Temperature, soil moisture content, NH 4 + , total nitrogen, total carbon and pH were the main environmental factors causing the niche differentiation between comammox Nitrospira and canonical nitrifiers. Collectively, our study expands the general insights into the niche distribution of comammox Nitrospira and the driving environmental factors in riparian wetland ecosystems around Taihu Lake. © 2022, The Authors. All rights reserved.

关键词： Nitrification

Simultaneous Water Softening and Selective Ammonia Nitrogen Recovery from Coal Gasification Gray Water Using an Innovative Four-Chamber Flow-Electrode Electrochemistry System

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SSRN 2023年

作者： Chen, Taoqin Wei, Sheng Xu, Longqian Tang, Xianchun Chen, Hongbin State Key Laboratory of Pollution Control and Resource Reuse College of Environmental Science and Engineering Tongji University Shanghai200092 China Key Laboratory of Yangtze River Water Environment Ministry of Education College of Environmental Science and Engineering Tongji University Shanghai200092 China

CDI-based technologies such as flow electrode capacitive deionization (FCDI) have shown great promise for desalination and resource recovery, but simultaneous desalination and resource recovery using one FCDI device has thus far received minimal attention. In this study, a novel four-chamber FCDI coupled with a monovalent cation exchange membrane (MCEM) was proposed to realize simultaneous desalination (including water softening) and ammonia-rich solution production from coal gasification gray water (CGGW). The results showed that under optimal conditions, up to 91.2 ± 0.1% ammonia nitrogen, 88.9 ± 1.0% Ca2+, and 92.6 ± 5.5% TOC of real CGGW were removed by the desalination chamber. Furthermore, passed through the MCEM and entered the recovery chamber, while Ca2+ was effectively blocked from entering the recovery chamber by MCEM. Thus, a value-added ammonia-rich solution with purity of 98.0% was obtained. The process was superior since two typical FCDI cells are needed to realize water softening and recover ammonia-rich solutions. The mechanistic insights into the proposed four-chamber FCDI coupled with MCEM can be expanded to other simultaneous desalination, ion separation and recovery processes. Thus, the four-chamber FCDI is a promising technology for simultaneous desalination and resource recovery with the advantages of being chemical-free, capital efficient and operable. © 2023, The Authors. All rights reserved.

关键词： Desalination

Competing Contributions in the Micro-Nano Bubble Ozonation Process in Degradating 2-Methylisobornyl (2-Mib) and Geosmin (Gsm): Revealing the Role of Free Radicals Versus Micro-Nano Bubbles

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SSRN 2024年

作者： Ren, Yuehua Wang, Yonglei Wang, Xinglin Liu, Baozhen He, Guilin Gong, Yanli Liu, Baosen Li, Jingjing School of Municipal and Environmental Engineering Shandong Jianzhu University Jinan250101 China School of Environmental Science and Engineering State Key Laboratory of Pollution Control and Resource Reuse Tongji University Shanghai1239 China Jinan Environmental Research Academy Jinan250000 China

Seasonal algal contamination of lake and reservoir-type water sources leads to an increase in taste and odor compounds, such as 2-methylisobornyl alcohol (2-MIB) and geosmin (GSM). As a result, the effluent quality of water purification plants and the taste of drinking water are seriously affected. In this work, a coupled micro-nano bubble ozonation deep treatment process was constructed to investigate the degradation performance and mechanism underlying the micro-nano bubble ozonation process of 2-MIB and GSM. The results showed that the micro-nano bubble ozonation process could remove 94.38% of 2-MIB and 95.45% of GSM in 15 min, which was 36.11% and 29.56% higher than that of the common bubble ozonation process, respectively. Analysis of degradation products and toxicity showed that 2-MIB was oxidized by a micro-nano bubble ozonation process with bridge ring breaking and ring opening and finally decomposed into dextro-camphor-based steric double-bridged compounds. In addition, the toxicity of the products was significantly lower than that of 2-MIB, while GSM was first decomposed into isomers and other double-ringed substances and then ring-opened and broken into ketones, naphthalenes, alkanes and alcohols;however, the toxicity of only 50% of the intermediary products was reduced. Superoxide radical oxidation was the main mechanism for the reduced toxicity of 2-MIB and GSM in the micro-nano bubble ozonation process, in which the oxidizing capacities were 4.88% and 6.72% higher than those of hydroxyl radicals. The complete removal of 2-MIB and GSM in the micro-nano bubble ozonation process relied on synergistic effects resulting from micro-nano bubble-induced volatilization of the substances and ozone oxidation, and the contribution of the micro-nano bubble process to compound removal reached 75%. This work provides new insights for the development of deep treatment processes for the removal of taste and odor compounds from drinking water. © 2024, The Authors. All r

关键词： Potable water

Unveiling the crucial role of iron oxide transformation in simultaneous immobilization of nanoplastics and organic matter

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Science of the Total Environment 2025年 959卷 178280页

作者： Su, Chengpeng Peng, Cheng Liang, Weiyu Chen, Anqi Liu, Qiang Zhang, Wei State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process School of Resource and Environmental Engineering East China University of Science and Technology Shanghai200237 China Shanghai Institute of Pollution Control and Ecological Security Shanghai200092 China

Nanoplastics (NPs) have been found in natural environments. However, the sequestration of NPs and natural organic matter (NOM) coupled with the Fe(III) hydrolysis and subsequent iron oxides transformation remains unclear. Here, we investigated the behaviors of NPs during the dynamic transformation process of iron oxides in the presence of humic acids (HA). The quantification results of europium chelate-labeled polystyrene (PS) NPs and HA indicate that 87.60 % of NPs and 49.45 % of HA were sequestered in the precipitate by the end of the transformation (240 h). High-angle annular dark-field-scanning transmission electron microscopy-energy dispersive X-ray spectroscopy (HAADF-STEM-EDS) images show that NPs were doped into iron oxides during the recrystallization of ferrihydrite aggregates, while HA were adsorbed or penetrated into the nanoscale pores on the mineral surfaces, suggesting the formation of a stable iron oxides-NPs-NOM ternary nanocomplex with a core-shell structure. Fourier transform infrared spectrometer (FTIR) and two-dimensional correlation spectroscopy (2D-COS) analysis indicate that functional groups of iron oxides and HA, including hydroxyl, carboxyl, and Fe[sbnd]O bonds, played a role in the binding process. In the presence of HA, the stability of the coprecipitation system was enhanced due to the increased electrostatic repulsion, which facilitated the full incorporation of NPs with iron oxides. These findings provide a new insight into the simultaneous immobilization of NPs and NOM. © 2024 Elsevier B.V.

关键词： Energy dispersive spectroscopy

How Multi-Walled Carbon Nanotubes in Wastewater Influence the Fate of Coexisting Antibiotic Resistant Genes in the Subsequent Disinfection Process

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SSRN 2022年

作者： Wang, Min Wang, Yan Ni, Xiaoyu Hou, Xuan Ma, Defang Li, Qian Gao, Baoyu Shandong Key Laboratory of Water Pollution Control and Resource Reuse School of Environmental Science and Engineering Shandong University Qingdao266237 China

Wastewater treatment plants (WWTPs) are important hubs for the spread of antibiotic resistance genes (ARGs). Engineered nanoparticles, which was inevitably released to WWTPs, could change environmentally sensitive of antibiotic resistant bacteria (ARB). This would influence the fate of ARGs in subsequent disinfection process and consequent health risk. In this study, the ARGs fate of the effluent in conventional sodium hypochlorite (NaClO) disinfection process was investigated as multi-walled carbon nanotubes (MWCNTs) existed in sequencing batch reactor (SBR). The results showed the existence of MWCNTs in SBR could enhance the removal efficiency of intracellular 16S rRNA gene and intI1 , extracellular intI1 , sul2 and tetX in the effluent by NaClO. This is mainly due to the variation of bacterial physiological status, bacterial population structure and the activation of NaClO under the role of MWCNTs. MWCNTs in SBR could increase in membrane permeability of bacterial cells, which would be conducive to the penetration of chlorination to cytoplasm. MWCNTs in SBR also could change the bacterial population structure and induce the chlorine-sensitive bacteria;thus the potential hosts of ARGs in the effluent would be more easily inactivated by NaClO. Moreover, the residual MWCNTs in the effluent could activate NaClO to generate various free radical, which would enhance the oxidizing capacity of chlorination. © 2022, The Authors. All rights reserved.

关键词： Wastewater treatment

Degradation and mechanism of PFOA by peroxymonosulfate activated by nitrogen-doped carbon foam-anchored nZVI in aqueous solutions

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Chemosphere 2024年 351卷 141209页

作者： Li, Changyu Shen, Cong Gao, Bin Liang, Wenxu Zhu, Yifan Shi, Weijie Ai, Shiyun Xu, Hongxia Wu, Jichun Sun, Yuanyuan State Key Laboratory of Pollution Control and Resource Reuse Key Laboratory of Surficial Geochemistry Ministry of Education School of Earth Sciences and Engineering Hydrosciences Department Nanjing University Nanjing210023 China College of Chemistry and Material Science Shandong Agricultural University Shandong Taian271018 China Department of Civil and Environmental Engineering Rensselaer Polytechnic Institute TroyNY12180 United States

Perfluorooctanoic acid (PFOA) is an emerging pollutant that is non-biodegradable and presents severe environmental and human health risks. In this study, we present an effective and mild approach for PFOA degradation that involves the use of nitrogen-doped carbon foam anchored with nanoscale zero-valent iron (nZVI@NCF) to activate low concentration peroxymonosulfate (PMS) for the treatment. The nZVI@NCF/PMS system efficiently removed 84.4% of PFOA (2.4 μM). The active sites of nZVI@NCF including Fe0 (110) and graphitic nitrogen played crucial roles in the degradation. Electrochemical analyses and density functional theory calculations revealed that nZVI@NCF acted as an electronic donor, transferring electrons to both PMS and PFOA during the reaction. By further analyzing the electron paramagnetic resonance and byproducts, it was determined that electron transfer and singlet oxygen were responsible for PFOA degradation. Three degradation pathways involving decarboxylation and surface reduction of PFOA in the nZVI@NCF/PMS system were determined. Finding from this study indicate that nZVI@NCF/PMS systems are effective in degrading PFOA and thus present a promising persulfate-advanced oxidation process technology for PFAS treatment. © 2024 Elsevier Ltd

关键词： Paramagnetic resonance

Prediction of Free Radical Reactions Toward Organic Pollutants With Easily Accessible Molecular Descriptors

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SSRN 2023年

作者： Zhang, Guoyang Zhu, Qiang Zheng, Hongcen Zhang, Shujuan Ma, Jing State Key Laboratory of Pollution Control and Resource Reuse School of Environment Nanjing University Nanjing210023 China Key Laboratory of Mesoscopic Chemistry of Ministry of Education Institute of Theoretical and Computational Chemistry School of Chemistry and Chemical Engineering Nanjing University Nanjing210023 China

Machine learning (ML) is becoming an efficient tool for predicting the fate of aquatic contaminants owing to the preponderance of big data. However, whether ML can "learn" the differences in reactivity among different free radicals has not yet been tested. In this work, the effectiveness of combining ML algorithms with molecular fingerprints to predict the reactivity of three free radicals is evaluated. Firstly, a dataset containing 211 contaminants and their rate constants with carbonate radical (CO3•−) was used to develop predictive models by linear regression and ML. The employment of topologically atomic alignment information, in terms of molecular access system (MACCS) and Morgan Fingerprint, and the electronic structure features (energy levels of the highest-occupied and lowest-unoccupied molecular orbitals, EHOMO and ELUMO, and the energy gap between ELUMO and EHOMO) gave satisfactory predictive performances (ML model with Random Forest algorithm with MACCS: RMSEtest = 0.787;linear regression model with energy levels: RMSEtest = 0.641). Additionally, the model interpretation correctly described that the key reactivity features for CO3•− were relatively close to those for SO4•− rather than those for OH. These results suggest that the combination of ML algorithms with easily accessible molecular fingerprints would be a powerful tool to accurately predict the radical reactions towards organic compounds. © 2023, The Authors. All rights reserved.

关键词： Electronic structure

Competing Contributions in the Micro-Nano Bubble Ozonation Process in Degradating 2-Methylisobornyl (2-MIB) and Geosmin (GSM): Revealing the Role of Free Radicals Versus Micro-Nano Bubbles

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SSRN 2024年

作者： Wang, Yonglei Ren, Yuehua Wang, Xinglin Liu, Baozhen He, Guilin Gong, Yanli Liu, Baosen Li, Jingjing School of Municipal and Environmental Engineering Shandong Jianzhu University Jinan250101 China School of Environmental Science and Engineering State Key Laboratory of Pollution Control and Resource Reuse Tongji University Shanghai1239 China Jinan Environmental Research Academy Jinan250000 China

Algal contamination leads to an increase in taste and odor compounds, such as 2-methylisobornyl alcohol (2-MIB) and geosmin (GSM). In this work, a coupled micro-nano bubble ozonation deep treatment process was constructed to investigate the degradation performance and mechanism underlying the micro-nano bubble ozonation process of 2-MIB and GSM. The results showed that the micro-nano bubble ozonation process could remove 94.38% of 2-MIB and 95.45% of GSM in 15 min, which was 36.11% and 29.56% higher than that of the common bubble ozonation process, respectively. Analysis of degradation products and toxicity showed that 2-MIB was oxidized by a micro-nano bubble ozonation process with bridge ring breaking and ring opening and finally decomposed into dextro-camphor-based steric double-bridged compounds. The toxicity of the products was significantly lower than that of 2-MIB, while GSM was first decomposed into isomers and other double-ringed substances and then ring-opened and broken into ketones, naphthalenes, alkanes and alcohols;however, the toxicity of only 50% of the intermediary products was reduced. Superoxide radical oxidation was the main mechanism for the reduced toxicity of 2-MIB and GSM in the micro-nano bubble ozonation process, in which the oxidizing capacities were 4.88% and 6.72% higher than those of hydroxyl radicals. The complete removal of 2-MIB and GSM in the micro-nano bubble ozonation process relied on synergistic effects resulting from micro-nano bubble-induced volatilization of the substances and ozone oxidation, and the contribution of the micro-nano bubble process to compound removal reached 75%. © 2024, The Authors. All rights reserved.

关键词： Potable water

An Enhanced Particle Swarm Optimization with Levy Flight for RBF Neural Network in Typical Karst Area, South China

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An Enhanced Particle Swarm Optimization with Levy Flight for...

International Conference on Intelligent and Fuzzy Systems, INFUS 2020

作者： Cao, Zhangjun Wang, Dong Wang, Lachun Key Laboratory of Surficial Geochemistry Ministry of Education Department of Hydrosciences School of Earth Sciences and Engineering State Key Laboratory of Pollution Control and Resource Reuse Nanjing University Nanjing China School of Geographic and Oceanographic Sciences Nanjing University Nanjing China

ISBN: (纸本)9783030511555

This paper applied an enhanced particle swarm optimization (PSO) technique with levy flight algorithm for training the radial basis function (RBF) neural network to forecast the data of runoff in the Houzhaihe River basin, a typical karst area in Guizhou Province, southwest China. The karst aquifer system is a highly nonlinear and complex system due to its unique aqueous medium, the complexity of its hydrogeological conditions makes the traditional hydrological model research results unsatisfactory, and the establishment of a physical distributed model based on hydrological mechanism requires a large number of hydrogeological parameters, which are often unavailable in karst areas. Radial Basis Function (RBF) neural network has been widely used in various fields because of its simple structure, high-speed calculation and ability to approximate any nonlinear function. Based on the RBF neural network, this paper established a time series prediction model for typical karst regions. In order to improve the performance of RBF network model, we applied an enhanced particle swarm optimization with levy flight in this research. The results show the proposed enhanced RBF model performs much better than the one without improvement by the levy flight. © 2021, The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Switzerland AG.

关键词： Radial basis function networks