APPLIED CLAY SCIENCE
·
2023
·
IF 5.6
Fang Wang,Pingxiao Wu,Meiqing Chen,Jiayan Wu,Leiye Sun,Zhongbo Shang,Nengwu Zhu
Green rust (GR), as one of mixed-valent iron [Fe(II)-Fe(III)] minerals, has received a significant attention in recent years because it is an intrinsic and essential part of biogeochemical cycling of heavy metals and DOM . The transformation of GR is a key factor in altering the environmental behavior of heavy metals, and therefore, prediction of such transformation is critical for managing environmental quality. DOM and heavy metals are recognized to have a significant impact on iron oxide transformation. However, detailed information on these phenomena and mechanisms are still limited. In this study, Cr(VI) and oxalic acid (OA) widely distributed in the natural environment were selected representatives of heavy metals and DOM. The mechanism of their influence on GR transformation and their environmental significance were clarified. GR transformed to feroxyhyte under the impact of Cr(VI) and OA, and feroxyhyte did not transform to more crystalline iron oxides after 7 days. However, OA enhanced Fe dissolution and Cr(VI) reduction while weakening the immobilization of Cr on GR. SEM results demonstrated that OA addition resulted in the collapse of the feroxyhyte structure. SEM-EDS data indicated that Cr and OA were adsorbed on GR, suggesting that this can be an essential pathway for C and Cr sequestration during GR transformation. This study reveals Cr(VI) not only favors the formation of feroxyhyte, but also stabilizes the mineral to prevent transformation and meanwhile indicates the mechanisms of organic matter interactions with iron oxide and the environmental behavior of C and Cr during the iron oxide transformation processes.
研究领域:
环境科学
·
地球化学
✓ 已验证
产品关联
DOI
高影响因子
WATER RESEARCH
·
2025
·
IF 12.4
Chuanjin Lin,Bin Dong,Zuxin Xu
Iron and organic carbon (OC) biogeochemical cycling is highly correlated, and dissolved organic matter (DOM), a highly reactive component of soil and water environments, is the main OC source. However, the micro-mechanism of the molecular fractionation of DOM, the spatial OC distribution on iron (oxyhydr)oxides, and how these factors further affect their redox properties remain to be fully understood. Therefore, this study investigated the DOM adsorption properties of iron (oxyhydr)oxides with different crystallinities at the molecular level through the Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) and transmission electron microscopy/electron energy loss spectroscopy (TEM–EELS) analyses of the liquid-solid phases. Owing to the limited number of adsorption sites, OC sequestration on goethite and hematite surfaces generally followed an “onion” model, in the order of preference of aromatic, aliphatic, and carboxylic acid-rich compounds. Combined with dielectric electrochemical tests and charge differential density calculations, the results revealed that the complexation effect produced by iron ions increased the electron-accepting capacity (EAC) of the DOM remaining in the aqueous solution. In contrast, molecular selective adsorption and oxidative polymerization significantly enhanced the EAC of DOM adsorbed on the surface fraction of iron (oxyhydr)oxides. These findings help elucidate the mechanism of OC sequestration by iron (oxyhydr)oxides. The increased EAC may affect various biogeochemical processes, such as methane production and microbial Fe(III) reduction, facilitating the prediction of OC cycling in natural environments.
研究领域:
环境科学
·
土壤学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Fundamental Research
·
2022
·
IF 0
Enyao Zhang,Yalan Chen,Yang Li,Ke Sun,Yan Yang,Bo Gao,Baoshan Xing
Microplastics (MPs) and chromium (Cr) are common pollutants in wastewater treatment plants, where ultraviolet disinfection processes may degrade MPs and photooxidize Cr(III) into more hazardous Cr(VI). In this study, the effects of MPs on the phototransformation of coexisting Cr, as well as the role and ecological effects of MPs-derived dissolved organic matter (MPs-DOM), were investigated. The photooxidation of MPs and Cr(III) was radical-driven reaction. The addition of MPs inhibited the photooxidation of Cr(III) and induced the photoreduction of Cr(VI) through surface adsorption. Both MPs and MPs-DOM generated comparable ROS at different irradiation moments, which can affect the photodegradation of MPs and MPs-DOM, as well as the phototransformation of Cr. The 56-day incubation showed a higher mineralization ratio of MPs-DOMs than riverine humic acid, indicating the vital contribution of MPs-DOMs to carbon emissions. In general, MPs-DOM lowered microbial abundance and diversity compared to the original inoculum. Bacterial and fungal succession was affected by both MPs-DOM and the original inoculum, with polyvinyl chloride-derived DOM possessing a stronger filtration impact on microbial communities than the other three MPs-DOMs. In this study, a win–win solution for Cr(VI) reduction and MPs treatment through photoirradiation was proposed, and the potential significant role of MPs-DOM in the transformation of coexisting contaminants, the carbon cycle, and microbial succession was highlighted.
研究领域:
环境科学
·
水处理
·
化学
·
微生物学
·
生态学
✓ 已验证
产品关联
DOI
PubMed
ENVIRONMENTAL POLLUTION
·
2020
·
IF 6.793
Fan Zhang,Xue Li,Lizeng Duan,Hucai Zhang,Wen Gu,Xingxin Yang,Jingping Li,Sen He,Jie Yu,Meijie Ren
Dissolved organic matter (DOM) and dissolved ions are two integral parameters to affect the environmental fate of As in different ways. Numerous studies chose surrogate of DOM, humic substances (HSs), to investigate the As complexation behavior. However, microbial secretion (protein and polysaccharide) was also considered for a great proportion in surface aquatic system, and its effect was still not fully understood. The present research distinguished the As complexation behavior with different DOM components (HSs, protein, polysaccharide and synthetic organic matter) in natural and simulated water samples. The results indicated that different DOM components exhibited various binding capacities for As. HSs showed the strongest affinity for As, followed by long-chain compounds (polysaccharide and synthetic organic matter) and proteins. In water source, HSs were probably the primary parameter for As complexation. In eutrophic water system, however, polysaccharide maybe the main DOM component to bind As. Cationic bridge function was prone to occur in the presence of HSs, but not observed in the presence of protein. PO 4 3− competed for binding sites with As, consequently decreasing the As complexation with all the DOM components. The research implied that a comprehensive and meticulous analyses of DOM fractions and coexist ions are the prerequisite to understanding the behavior of As (or other pollutants) in different natural aquatic systems.
研究领域:
环境科学
·
水文学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2024
·
IF 12.2
Weijun Li,Guobin Liu,Ming Lei,Yaoyu Zhou,Haojie Cui,Huihui Du
Tungsten (W), a widely used yet understudied emerging contaminant, forms oxyanions in aqueous environments, distinguishing it from conventional heavy metals. While dissolved organic matter (DOM) demonstrates considerable potential for W binding, DOM-W interactions remain largely unexplored. Of particular significance, yet frequently overlooked, are the conformational changes in DOM during W binding processes. This study proposes a novel theoretical framework integrating superposition and charge transfer models to elucidate the complexity of these interactions. By combining spectroscopic techniques and photophysical models, we revealed that aromatic compounds containing 1–3 rings, especially monocyclic aromatic protein-like components, exhibit high affinity for W (log K =3.74–4.00). Phenolic hydroxyls served as primary binding sites for W, with aromatic rings facilitating binding through π interactions. Importantly, W binding to aromatic compounds induced conformational changes in DOM, transitioning from a loosely aggregated state to a more compact configuration. These changes facilitated W encapsulation within DOM through the synergistic effects of hydrophobic interactions, hydrogen/π-hydrogen bonding and π-stacking, potentially leading to stable trapping of W. Two-dimensional correlation spectroscopy analysis elucidated the sequential encapsulation process, involving phenolic, aromatic carboxylic/aliphatic carboxylic, polysaccharides, and aliphatics. The intricate behavior of DOM-W binding profoundly reshapes DOM's conformation, subtly yet significantly orchestrating W's binding affinity, environmental transport, and bioavailability in aquatic ecosystems.
研究领域:
环境科学
·
光谱学
·
生态学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
WATER RESEARCH
·
2024
·
IF 11.4
Yang Deng,Shansheng Mo,Gregory V. Korshin,Mingquan Yan
Differential absorption spectroscopy (DAS) quantifies changes in the UV–Visible absorbance of dissolved organic matter (DOM) caused by reactions of its chromophores. As a result of its precision and sensitvity, DAS serves as a powerful tool for characterizing the formation of disinfection by-products (DBPs) in generated in DOM chlorination reactions. However, the nonlinear relationship between the intensity of DAS and DBP concentrations as well as the need to develop site-specific fitting parameters limit its practical applications. This study investigated the physico-chemical nature of DAS of chlorinated DOM through experimental measurements and theoretical calculations. Results of this study provide molecular-level evidence that electrophilic substitution reactions involving DOM reactive sites result in the emergence of DAS feaures ascribed to the "fast" chromophores. The ring opening in the cyclic enones-like structures which can be present either in the original DOM or are generated as intermediates in its chlorination, leads to the emergence of DAS features associated with the "slow" chromophores and high yields of DBPs. The kinetic study of chlorination of real waters reveals a strong linear relationship (R 2 > 0.91) between ln([DBP]) and the long-wavelength (λ > 325 nm) parameter of the DAS, notably (ln(-DA 350 )). This relationship varies among different water sources due to the differences in the heterogeneity of Band A 3 whose maximum is near 350 nm. Band A 3 is one of the Gaussian bands that comprise the overall UV–Visible spectrum of DOM. A new function ( f ( − D A 350 ) ) is proposed in this study to quantify DBP formation. This function, which is determined by the Band A 3 's area, allows establishing a universal linear relationship between f ( − D A 350 ) and ln([THMs]), as well as f ( − D A 350 ) and ln([HAAs]), across various water sources. The findings of this study will stimulate further development of spectroscopy-based DBP monitoring technology for monitoring and optimization of water disinfection processes.
研究领域:
环境科学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMOSPHERE
·
2020
·
IF 5.778
Guocheng Zhu,Yongning Bian,Andrew S. Hursthouse,Shengnan Xu,Nana Xiong,Peng Wan
Dissolved organic matter (DOM) is not only a vector for the migration of aquatic environmental pollutants, but is also key to the control of water pollution . Economic and effective DOM removal through coagulation is essential in water treatment processes. This work investigated the role of carboxylated magnetic metal organic frameworks (MMOFs) nanoparticles in polymeric iron-based coagulation for the removal of aquatic DOM using a MMOFs-doped polyferric iron-based coagulant (MMOF-PIC). Analytical methodologies and tools used in this research included scanning electron microscopy (SEM), zeta potential , molecular weight cut off (MWCO), vibrating sample magnetometer (VSM) measurement, excitation emission matrix spectroscopy (EEMs), and X-ray photoelectron spectroscopy (XPS). The results showed that MMOF-PIC had the potential to change the structure of the polyferric iron-based coagulant (PIC) and charge, as determined by a porous surface morphology, a higher medium polymeric species distribution, and a more positive zeta potential. The MMOFs consequently enhanced PIC action on the removal of UV254 exposed DOM species with molecular weight <30 kDa, including aromatic C C based compounds, org-N as primary amines and amide/peptide bound species, water containing microbial metabolites and protein-like materials. The coagulation of DOM was enhanced by improving charge neutralization, adsorption-bridging and sweep-flocculation in the presence of MMOFs nanoparticles. This was due to hydrogen bonds , π-π bonds and covalent bonds resulting from actions of nanoparticles and pollutants. These results indicate that magnetic MOF nanoparticles can improve PIC coagulation for DOM, enhancing future removal of target pollutants.
研究领域:
环境科学
·
材料科学
·
水处理技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
WATER AIR AND SOIL POLLUTION
·
2026
·Vol. 237
·期 18
·1052
·
IF 3.5
Su Zhaoxin,Xiong Yankai,Wang Zhijie,Wang Xiufen,Li jiayi,Wang Mujie
Antibiotic contamination in rivers threatens ecosystem integrity and promotes the dissemination of antimicrobial resistance. Dissolved organic matter (DOM) regulates antibiotic photodegradation via photosensitization, light screening, and complexation. This study examined the occurrence of representative antibiotics in the mainstream of the Xiaoqing River and evaluated the role of DOM composition in regulating their photodegradation under simulated sunlight conditions. Target compounds included macrolides (erythromycin [ETM], roxithromycin [RTM], and tilmicosin), fluoroquinolones (norfloxacin [NOR] and ofloxacin), and a sulfonamide (sulfamethoxazole [SMX]). Field monitoring combined with laboratory irradiation experiments was conducted to characterize DOM fluorescence components (C1–C3) and quantify their effects on antibiotic photodegradation. Most target antibiotics in the Xiaoqing River mainstream occurred at concentrations below global average levels reported for surface waters. However, SMX exhibited a high detection frequency, and RTM was detected in all samples with the highest mean concentration, longitudinal analysis showed that total antibiotic concentrations increased downstream into the urban center, indicating a substantial municipal wastewater influence. EEM–PARAFAC analysis identified three prevalent DOM components: C1 (visible-region fulvic-like), C2 (UV-region fulvic-like), and C3 (tyrosine-like protein-like), with C2 dominating the DOM pool. Photodegradation experiments revealed pronounced DOM-specific effects. Humic acid (HA) generally enhanced degradation (e.g., ETM, k obs = 0.2628 h −1 , R 2 = 0.81), whereas fulvic acid (FA) strongly inhibited NOR photodegradation ( k obs = 0.0006 h −1 ). Tryptone alone suppressed photodegradation but produced synergistic enhancement when combined with HA and FA (NOR, k obs = 0.0671 h −1 ). In contrast, SMX exhibited limited photoreactivity under simulated sunlight in all DOM treatments. Overall, these results demonstrate that DOM composition is a key regulator of antibiotic photochemical fate in anthropogenically impacted rivers, and that interactions among DOM components and antibiotic molecular structures govern photodegradation behavior.
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2026
·
IF 12.2
Meng Xiangjun,Chi Jialin,Yin Mengmeng,Wu Shiyin,Liu Kai,Zhang Xin,Jiang Kai,Putnis Christine V.,Zhou Xiaoxia,Fang Liping,Li Fangbai
Microbial respiration-triggered reductive transformation
of dissolved
organic matter (DOM) plays a central role in O 2 activation
and, consequently, As(III) oxidation under fluctuating hydrological
conditions. However, the key DOM components and their molecular transformations
associated with this electron-transfer process remain poorly resolved.
Here, by integrating Fourier transform ion cyclotron resonance mass
spectrometry with machine learning, we reveal that fulvic acid (FA),
the predominant DOM fraction, undergoes selective molecular transformation
by Geobacter sulfurreducens PCA, forming
a reactive subpool that drives O 2 activation and thereby
enhances As(III) oxidation by approximately 2–10 fold. Reaction
network analysis reveals that oxygen-rich aromatic precursors are
preferentially transformed into more reduced intermediates through
decarboxylation, dehydrogenation, and partial reduction pathways.
These transformations collectively shift the molecular composition
toward lower oxidation states and enhanced redox reactivity. Machine-learning
analysis further identifies nitrogen- and sulfur-containing molecules
with low oxidation states as the key components governing the overall
redox activity of the system. These species represent a functionally
distinct fraction of microbially transformed FA with enhanced electron-donating
capacity. This study provides molecular-level insights into how microbial
DOM transformation regulates O 2 activation and As(III)
oxidation, offering a mechanistic basis for predicting and manipulating
redox reactivity in dynamic soil and sediment systems.
✓ 已验证
产品关联
DOI
高影响因子
MICROCHEMICAL JOURNAL
·
2024
·
IF 4.9
Fan Yang,Jiao Liu,Yanjie Xie,Meijie Ren
Pharmaceuticals and personal care products (PPCPs) were widely present in the water environment, posing a threat to both the ecological environment and human health. Dissolved organic matter (DOM) was ubiquitous in aquatic system and could form strong complexes with PPCPs, thereby interfering with accurate quantification. This paper proposed a novel method that utilized ultraviolet differential spectroscopy to accurately quantify PPCPs in DOM-PPCPs coexisting systems. A linear regression equation was established between UV–vis absorbance change (ΔA) at the characteristic peaks of specific PPCP and its concentration, resulting in the creation of a standard curve. The coefficient of determination (R 2 ) of the linear regression equations established by four DOM (humic acid, fulvic acid, bovine serum albumin and sodium alginate) and the given PPCPs were consistently above 92 %. Moreover, real water samples were collected for the purpose of conducting a standard recovery experiment. The recovery rates of three types of PPCPs (carbamazepine, sodium sulfadiazine and triclosan) ranged from 90 % to 120 %, suggesting the feasibility of quantifying PPCPs in the DOM-PPCPs coexisting system using this method. The method proposed for quantifying PPCPs in DOM-PPCPs coexisting systems using UV differential spectroscopy introduced a new approach to quantifying PPCPs.
研究领域:
环境科学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL RESEARCH
·
2022
·
IF 8.431
Xuelian Xia,Yanguo Teng,Yuanzheng Zhai
Riverbank filtration (RBF) constitutes an important part of the water cycle , which involves active natural filtration leading to pollution of river water being intercepted and retained. The RBF has the function of water purification , but retention of exogenous pollutants in the RBF system complicates biogeochemical processes due to the presence of primary active components. In this study, we verified the essential role of microbial mediation during the interactions between primary Fe minerals in the RBF system and dissolved organic matter (DOM) in river water based on lab-scale experiments. The results demonstrated that DOM from infiltration of river water increased the amount of iron (Fe) released from the sediment in RBF, leading to an increase in Fe concentration in groundwater by higher than one order of magnitude. In particular, the existence of Fe bacteria even made this effect more thorough and more complex. Abiotic reduction was shown to play a more significant role in increasing Fe release than microbe-mediated reduction. Increasing the amount of Fe released could change the distribution of Fe minerals at the sediment surface, thereby affecting the structure of the microbial community in the RBF system and decreasing the DOM concentration in the groundwater. Moreover, As and Mn were found to behave in a similar manner as Fe due to their close biochemical properties when interacting with primary minerals in sediment. This study not only provides mechanistic insight into the higher Fe concentrations encountered in the groundwater of nearby rivers but also has important practical implications for developing nature-based technologies for water pollution control and environmental remediation.
研究领域:
环境科学
·
水文地质学
·
生物地球化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2023
·
IF 9.8
Xuelian Xia,Weifeng Yue,Yuanzheng Zhai,Yanguo Teng
Hyporheic zone (HZ) systems have a natural purification capacity, and they are commonly used to provide high quality drinking water . However, the presence of organic contaminants in HZ systems in anaerobic environments causes the aquifer sediments to release metals (e.g., Fe) at levels above drinking water standards, which affects the quality of groundwater. In this study, the effects of typical organic pollutants (dissolved organic matter (DOM)) on Fe release from anaerobic HZ sediments were investigated. Ultraviolet fluorescence spectroscopy , three-dimensional excitation-emission matrix fluorescence spectroscopy, excitation–emission matrix spectroscopy coupled with parallel factor analysis and Illumina MiSeq high-throughput sequencing were used to determine the effects of the system conditions on Fe release from HZ sediments. Compared with the control conditions (low traffic and low DOM as a baseline), the Fe release capacity was enhanced by 26.7 % and 64.4 % at low flow rate (85.8 m/d) and high organic matter concentration (1200 mg/L), which was consistent with the residence-time effect. The transport of heavy metals under different system conditions varied with the influent organic composition. The influent organic matter composition and fluorescence parameters (the humification index, biological index and fluorescence index) were closely related to the release of the Fe effluent, while these factors had less influence on Mn and As. From 16S rRNA analysis of the aquifer media at different depths at the end of the experiment, under low flow rate and high influent concentration conditions, reduction of Fe minerals by Proteobacteria , Actinobacteriota , Bacillus , and Acidobacteria promoted the release of Fe. These functional microbes play an active role in the Fe biogeochemical cycle in addition to reducing Fe minerals to promote Fe release. In summary, this study reveals the effects of the flow rate and influent DOM concentration on the release and biogeochemistry of Fe in the HZ. The results presented herein will contribute to a better understanding of the release and transport of common groundwater contaminants in the HZ and other groundwater recharge environments.
研究领域:
环境科学
·
水文学
·
微生物学
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）