Journal of Water Process Engineering
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2023
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IF 7
Yuying Hu,Xin Wang,Xiaohuan Zheng,Kangqi Jiang,Hao Deng,Xiaoming Peng,Hongling Dai,Yang Wei,Fengping Hu
Natural organic matter (NOM) widely exists in natural water bodies and threat drinking water safety. This study aims to construct an integrated photocatalytic/coagulation system and explore its treatment efficiency for NOM in source water. Morphological characteristics of the floc complex were studied based on the machine vision detection system. In addition, structural change characteristics of the floc complex in the integrated photocatalytic/coagulation system were revealed from microscopic perspective to clarify the mechanism of its effect in source water treatment process. And recycling and recycling method of photocatalyst was optimized. The results showed that the integrated photocatalytic/coagulation system can effectively reduce generation of DBPs at concentration level of μg·L −1 , and the formed petal-like BiFeO 3 -core floc complex can achieve rapid sedimentation and had excellent recycling performance. The construction of integrated photocatalytic/coagulation system in this study is expected to provide a theoretical basis for achieving low consumption and high efficiency improvement of source water quality.
研究领域:
环境科学
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水处理工程
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DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2024
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IF 12.2
Yi Yan,Hui Xu,Zijie Wang,Hongni Chen,Liwei Yang,Yan Sun,Chuanliang Zhao,Dongsheng Wang
Currently, the hidden risk of microplastics in the coagulation process has attracted much attention. However, previous studies aimed at improving the removal efficiency of microplastics and ignored the importance of interactions between microplastics and natural organic matter (NOM). This study investigated how polystyrene micro/nano particles impact the release of NOM during the aging of flocs formed by aluminum-based coagulants Al 13 and AlCl 3 . The results elucidated that nano-particles with small particle sizes and agglomerative states are more likely to interact with coagulants. After 7 years of floc aging, the DOC content of the nano system decreased by more than 40%, while the micron system did not change significantly. During coagulation, the benzene rings in polystyrene particles form complexes with electrophilic aluminum ions through π-bonding, creating new Al-O bonds. NOM tends to adsorb at micro/nano plastic interfaces due to hydrophobic interactions and conformational entropy. In the aging process, the structure of PS-Al 13 or PS-AlCl 3 flocs and the functional groups on the surface of micro/nano plastics control the absorption and release of organic matter through hydrophobic, van der Waals forces , hydration, and polymer bridging. In the system with the addition of nano plastics, several DBPs such as TCAA , DCAA , TBM , DBCM and nitrosamines were reduced by more than 50%. The reaction order of different morphological structures and surface functional groups of microplastics to Al 13 and AlCl 3 systems is aromatic C-H > C-OH > C-O > NH 2 > aromatic C C > aliphatic C-H and C-O>H-C O> NH 2 >C-OH> aliphatic C-H. The results provided a new sight to explore the effect of micro/nano plastics on the release of NOM during flocs aging.
研究领域:
环境科学
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化学工程
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DOI
PubMed
高影响因子
WATER RESEARCH
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2024
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IF 11.4
Jie Chen,Peizeng Yang,Jing Chen,Bin Gao,Junhe Lu
This study investigated the expediated transformation of halophenols in the presence of nitrite (NO 2 − ) under slightly acidic conditions in ice, whereas such transformation was negligible in liquid water at 4 °C. We proposed that this phenomenon was attributed to the freeze-concentration effect, incurring a pH drop and the aggregation of NO 2 − and halophenols within the liquid-like grain boundary layer amid ice crystals. Within this micro-environment, NO 2 − underwent protonation to generate reactive nitrous acid (HNO 2 ) and nitrosonium ions (NO + ) that facilitate the nitration and oxidation of halophenols. When 10 μМ halophenol was treated by freezing in the presence of 5 μМ NO 2 − , the total yields of nitrated products reached 2.4 μМ and 1.4 μМ within 12 h for 2-chlorophenol (2CP) and 2-bromophenol (2BP), respectively. NO + drove oxidative coupling reactions, generating hydroxyl polyhalogenated diphenyl ethers (OH-PBDEs) and hydroxyl polyhalogenated diphenyls via C-O or C-C coupling. These two pathways were intricately intertwined. The presence of natural organic matter (NOM) mitigated the formation of nitrated products and completely suppressed the coupling products. This study offers valuable insights into the fate of halophenols in ice and suggests potential pathways for the formation of nitrophenolic compounds and OH-PBDEs in natural cold environments. These findings also open up a new avenue in environmental chemistry research.
研究领域:
环境化学
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低温环境化学
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水处理
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DOI
PubMed
高影响因子
JOURNAL OF MEMBRANE SCIENCE
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2026
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IF 8.8
Langrun Song,Jun Nan,Yunyun Cao,Hui Zhang,Xiaoyue Zhang,Zhencheng Ge,Wenxing Jin,Ying Wang,Meng Chen
Ultra-low-pressure ceramic microfiltration (ULPCM) is fundamentally constrained by the permeability-selectivity trade-off: the accumulation of compact cake layers increases hydraulic resistance, whereas the intrinsic large pore size of microfiltration membranes limits the rejection of trace micropollutants. In this study, a tri-functional quaternary ammonium silane (AC) was introduced during polyaluminum chloride (PACl) pre-coagulation to regulate floc architecture and engineer the structure of the coagulation-derived cake layer. During 360 h (15 d) of continuous operation in both synthetic surface water and actual surface water, the AC-integrated system achieved a stable normalized flux (J/J 0 = 0.38-0.40) and exceptional PFOA sequestration (>93.71%), significantly outperforming conventional systems. Molecular dynamics (MD) simulations and spectroscopic analyses (XPS/FT-IR) elucidated that the C 18 alkyl chains and quaternary ammonium groups dictate PFOA capture through synergistic hydrophobic and electrostatic interactions, while hydrophilic silanol groups enhance dissolved organic carbon (DOC) removal via hydrogen bonding. At the interfacial level, XDLVO theory and dynamic light scattering (DLS) quantification revealed that AC effectively regulates the thermodynamics of floc adhesion, promoting the assembly of a highly branched, low-fractal-dimension (D f ) scaffold. Morphology measurements confirmed that the engineered cake layer maintained a high porosity (up to 62.79%) with a pore size distribution dominated by micro-channels (< 0.5 μm), which enhanced the water permeability of the cake layer and its retention capacity for foulants. Integrated fouling analysis using Hermia, Tansel, and saturation decay models, together with statistical evaluation, demonstrated that floc size, cake layer porosity, pore size distribution, and AC-induced hydrophobic interactions played key roles in mitigating membrane fouling and enhancing contaminant retention. These findings highlight that regulating floc architecture via amphiphilic coagulant aids provides an effective strategy for engineering cake layer microstructure and mitigating membrane fouling in low-pressure microfiltration systems.
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DOI
高影响因子
Journal of Water Process Engineering
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2023
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IF 7
Rui Yu,Yanling Yang,Liping Tian,Xing Li,Chunjiao Liu,Tianjie Sun,Haiqing Chang,Zhiwei Zhou
A novel visible photocatalysis nanomaterials Bi 2 O 3 /rGO/TiO 2 (BRGT) was combined with polyethersulfone membrane (PES) and ceramic membrane (CM), respectively, to investigate the natural organic matter (NOM) removal performance, membrane fouling behavior and interfacial interactions. The results showed that NOM removal mainly by superoxide radical-dominated photocatalysis followed by membrane rejection enhancing the removal of fluorescent humic and proteins. Compared with PES, CM could more effectively retain the low molecular weight acidic intermediates and transitional or/and hydrophilic organic fractionations generated by photocatalysis. The mixture of NOM with BRGT (without photocatalysis) reduced the reversible fouling of the PES, causing an increase in the interfacial energy barrier of the fouling layer, while the opposite phenomenon was observed for CM. The photocatalysis time affected the membrane fouling, with short photocatalysis times (5 min) causing an increase in irreversible fouling. Extending the photocatalysis time, the interfacial interaction of the PES dominated by Lewis acid-base repulsive interaction gradually increased. And the gradual decreased of interfacial interaction of CM dominated by Lewis acid-base and Lifshitz-van der Waals attractive interactions reduced the possibility of reversible and irreversible fouling, respectively. This study provided a deeper mechanistic understanding for the application of a novel photocatalyst in combination with ultrafiltration .
研究领域:
环境科学
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材料科学
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DOI
高影响因子
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY
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2019
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IF 3.261
Qiwen Du,Weichen Jia,Jingyu Dai,Chao Du,Aiyun Shao,Rongmin Zhang,Yuefei Ji
Natural organic matter (NOM) contains a large number of aromatic ketones and quinones, which can produce reactive oxygen species (ROS), such as 1 O 2 and HO·, through photosensitization. These ROS play important roles in the attenuation of organic pollutants in sunlit surface water. The NOM components fractionated with XAD-8 resin at different pH influence the photo-generation of ROS, which may be related to the degree of dissociation of functional groups. In this study, probe chemicals were used to investigate the effect of dissociation degree (p K a ) of NOM model compounds on ROS production under 254 nm UV irradiation. Experimental results showed that six model compounds with similar molecular weights and structures but different p K a values have different ROS production abilities in a pH 7.0 reaction system. The ability for DHB 2,5 (2.97), DHB 3,4 (4.48), and GUA (9.99) to photo-generate 1 O 2 increased with increasing dissociation. The ability for DHB 3,4 and GUA to photo-generate HO· followed the same trend. The correlation between NOM dissociation constant and ROS generation is preliminary established, which explains the influence of functional groups. Our results may provide some basic information for understanding the correlation between NOM structural features and ROS generation.
研究领域:
环境化学
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光化学
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水处理
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环境科学
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产品关联
DOI
高影响因子
WATER RESEARCH
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2023
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IF 12.8
Kangying Guo,Chenghui Yu,Baoyu Gao,Beibei Liu,Zhining Wang,Yan Wang,Qinyan Yue,Yue Gao
Antibiotics bring potential risks to human health and ecosystem, and their coexistence with natural organic matters (NOMs) could have harmful impacts on the environment. Herein, a polyaluminium chloride (PAC)-polydimethyl diallyl ammonium chloride (PDMDAAC) dual coagulation process was designed to remove the co-pollutants of chlortetracycline (CTC) and humic acid (HA), representing antibiotics and NOMs, respectively. The main research strength was given to understand molecular interactions and their mechanisms associated with the coagulation and flocculation. We found that the co-existing HA and CTC increased the hydrophily and stability of contaminants, and generated HA@CTC complexes with large particles size. The interaction mechanism between CTC and HA was mainly hydrogen bonding, hydrophobic association action, n −π* electron donor-acceptor interaction, and π−π* conjugation. Lewis acid-base interaction was the main force between HA and CTC. The bonding energies of O H…N, O H…O, and hydrophobic association were −12.2 kcal/mol, −13.1 kcal/mol, and −11.4 kcal/mol, respectively, indicating that hydrogen bonding was stronger than hydrophobic association. The interactions between HA and CTC could improve their removal efficiency in the coagulation process. This is due to that the functional groups ( COOH and OH) in the HA@CTC could be adsorbed by Al based hydrolysates. Polar interaction dominated the CTC and HA removal, and PAC was more efficient than PDMDAAC to remove HA@CTC complexes due to its higher complexing capacity. Thanks to the low concentration of residual contaminants and the formation of large and loose flocs, the interaction of HA and CTC could alleviate membrane fouling during ultrafiltration process. This study will provide new insight into the efficient removal of combined pollution and membrane fouling control.
研究领域:
环境科学
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生物学
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产品关联
DOI
PubMed
高影响因子
WATER RESEARCH
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2022
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IF 13.4
Wenkai Liu,Changrong Zhao,Shiqing Zhou,Bin Liu,Xiaoxiang Cheng,Zhihao Xue,Tingting Zhu
This study was aimed to evaluate the effects of a pre-treatment involving sulfite (S(IV)) synergistically activated by ultraviolet (UV)/Fe(II) on natural organic matter (NOM)-enhanced Ca 2+ scaling during nanofiltration treatment. Based on the variations in the physicochemical properties and correlation analyses of irreversible resistance, the intrinsic fouling mechanisms were revealed from two aspects: bulk crystallization (interaction between NOM and inorganic ions) and surface crystallization (morphology of surface crystallization and a change in the Ca 2+ concentration in the scaling layer). Furthermore, the degradation contribution rates of different free radicals during the UV/Fe(II)/S(IV) (UFS) treatment process were evaluated. During the reactions in the UFS, three free radicals (SO·–4, OH ·– and e- aq) were generated, and in-situ Fe(III) was formed in-situ . The carboxyl groups of the NOM were attacked by the free radicals, resulting in decreased of carboxyl concentration and density. In addition, the bond between Ca 2+ and NOM weakened, and hydrophobic (HPO) substances were mineralized. However, the Fe(III) formed in-situ was active and electropositive, competing with Ca 2+ for the complexation active sites on the NOM. The synergy effect of bulk crystallization and surface crystallization led to a significant decrease in the particle size of feed solution. The crystal size and roughness of membrane surface also decreased, which was conducive to reducing the membrane irreversible resistance. Correlation analysis revealed that the HPO ratio, carboxyl density and particle size (> 100 nm) ratio were effective characterization parameters for predicting irreversible resistance. This study not only provides guidance for alleviating membrane fouling caused by NOM-enhanced Ca 2+ scaling during the nanofiltration process, but also presents the rationality of irreversible resistance during nanofiltration process and various indicators with strong linear correlation.
研究领域:
环境科学
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水处理工程
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DOI
PubMed
高影响因子
WATER RESEARCH
·
2025
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IF 12.4
Weijia Wang,Fei Wang,Zhongzhen Wang,Xianyang Shi,Chunyan Xu
The non-destructive, three-dimensional excitation-emission matrix (3D-EEM) based on fluorescence spectroscopy has been widely used in natural organic matter (NOM) monitoring in aquatic environments. However, the direct recognition of the species and concentration of NOM from 3D-EEM data remains challenging, especially under more complex scenarios such as in NOM mixtures and during ultrafiltration. In this work, first, we constructed a 3D-EEM spectral dataset for multi-task learning under various conditions. Then, we integrated the Transformer framework comprising a sparse spatial spectrum (S3) -aware attention mechanism and developed a novel deep learning model (S3Former) for identifying and predicting NOM species and concentrations. Our S3Former model excellently diagnosed sampled unary and binary NOM species (100% and 97.2%, respectively) and their concentrations (75% and 65.6%, respectively). The prediction accuracy, stability, and parameter efficiency of S3Former outperformed ten convolutional neural networks (CNN) models and the bare Transformer model. Finally, we applied the S3Former model to predict the NOM concentration ranges of ultrafiltration permeates, a more challenging prediction scenario due to the change in NOM molecular weights. Notably, our model demonstrated its robustness with good accuracy (up to 77% for humic acid). These results highlighted the potential of using S3Former to enhance automated water quality monitoring and control in water treatment.
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PubMed
高影响因子
WATER RESEARCH
·
2017
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IF 6.942
Mingquan Yan,Xuze Han,Chenyang Zhang
In this study, seven model compounds containing typical functional groups (phenolic and carboxylic groups) present in nature organic matter (NOM) were used to ascertain the nature of the characteristic bands in differential absorbance spectra (DAS) of NOM that are induced by metal ion binding. Some similarities were found between the DAS of the examined model compounds, caffeic acid , ferulic acid , sinapic acid , terephthalic acid , isophthalic acid , esculetin and myricetin and those of NOM. The binding of Cu(II) with carboxylic group might produce two peaks, A1 and A2, while the binding of Cu(II) with phenolic group might produce all four Gaussian peaks, from A1 to A4 displayed in the DAS of NOM. The UV–visible spectra predicted using time-dependent density functional theory (TD-DFT)-based methods met well with the experimental DAS of model compounds at different stages of Cu(II) binding. It demonstrates that the features in absorbance spectra are chiefly caused by HOMO (Highest Occupied Molecular Orbital) - LUMO (Lowest Unoccupied Molecular Orbital) transitions in the molecule and that the appearance of peaks in DAS reflects the changes of the molecular orbitals around reactive functional groups in a molecule before and after metal ion binding. The basis of the DAS features of NOM that are induced by metal ion binding could be identified primarily by the frontier molecular orbital theory .
研究领域:
环境化学
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光谱学
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计算化学
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水文地球化学
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DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
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2021
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IF 7.963
Chuan-Shu He,Rong-Rong Ding,Jia-Qi Chen,Guan-Nan Zhou,Yang Mu
While ubiquitous natural organic matters (NOMs) are capable of enhancing zero-valent iron (ZVI) performance under aerobic conditions , there is limited understanding of how the properties of NOMs affect the reactivity of ZVI towards contaminants removal. Here, the corresponding activity of ZVI under aerobic conditions was investigated in the presence of humic acid (HA), fulvic acid (FA), bovine serum albumin (BSA). It was found that three models of NOMs were all effective in promoting diatrizoate (DTA) reduction via depassivating ZVI. Interestingly, fast adsorption of NOM onto ZVI surface initially caused inconspicuous impact or visible inhibition on hydrophilic DTA reduction depending on their hydrophobicity . However, subsequent exposure of more reactive sites with high hydrophilicity arising from the detachment of surfaced NOM-associated iron oxide finally contributed to the enhanced consumption of Fe 0 with the ability: HA > FA ≈ BSA, and 1-2 times increase in DTA removal kinetic rate following the order: HA > FA > BSA. It further revealed that there were two key factors in determining DTA removal under aerobic conditions, including the ability of NOMs to boost Fe 0 consumption as contributed by their aromaticity degree and amino groups, and the hydrophobicity of NOMs to initially affect the property of ZVI surfaces.
研究领域:
环境科学
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化学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF MEMBRANE SCIENCE
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2023
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IF 9.5
Yanling Liu,Qihang Cen,Kaiming Fan,Airan Hu,Xu Yuan,Shengji Xia
Efficient removal of natural organic matter (NOM) and organic micropollutants (OMPs) while preserving essential mineral salts is a critical goal of high-quality drinking water production , which has not been satisfyingly achieved by available nanofiltration (NF) membranes. In this study, a facile modification strategy was developed to enhance membrane salt/organics selectivity, purposely utilizing the advantages of sulfonic acid groups including high hydrophilicity, strong acidity and low complexation propensity for divalent cations. The post-treatment using a heated alkaline solution of taurine endowed the membrane with reduced active layer thickness, properly enlarged pore size and more favorable surface characteristics inheriting from grafted sulfonic acid groups. Compared to the control one, the optimal modified membrane exhibited a more than doubled water permeance and significantly reduced rejections of Ca 2+ and Mg 2+ , while maintaining a high removal capacity for OMPs. The membrane superiority in the rejection selectivity between mineral salts and NOM was further demonstrated for natural surface water treatment, which outperformed a variety of commercial NF membranes. Improved dual resistance to Ca 2+ -involved organic fouling and scaling was also achieved by the sulfonic acid functionalized membrane with a higher passage of Ca 2+ . This study provides insights on the fit-for-purpose enhancement of membrane performance for more efficient water treatment.
研究领域:
环境科学
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水处理
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膜技术
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化学工程
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）