CHEMOSPHERE
·
2022
·
IF 8.943
Wenkai Liu,Bin Liu,Xin Li
The aim of this study was to investigate the feasibility and fouling mitigation mechanisms of UV/Fe(II) synergistically activated sulfite (S(IV)) (UFS) pretreatment to alleviate membrane fouling caused by HA-enhanced Ca 2+ scaling. After UFS treatment, hydrophobic substances and carboxyl groups structure were destroyed by the in-situ-generated SO•–4, resulted in a significant reduction of hydrophobic substances ratio and carboxyl group concentration. Due to the formation of more electropositive in-situ-generated Fe(III), the complexation between Ca 2+ and carboxyl groups was weakened so that the bulk crystallization size on the membrane surface was greatly reduced. The filter cake enhanced osmotic pressure effect (CEOP) and concentration polarization effect were hence alleviated, as well as the surface roughness . At the microcosmic perspective, as the energy barrier between the membrane and foulants was increased significantly after pretreatment, the anti -foulants adsorption ability of the membrane was enhanced. Correlation analysis showed that the carboxyl concentration and density, HPO ratio, larger particle size (>100 nm) ratio, the Ca 2+ concentration in the scaling layer and energy barrier all had a good correlation with the membrane resistance. This research not only provides an advanced oxidation technology that can effectively alleviate the synergistically-fouling effect of HA and Ca 2+ of nanofiltration process, but also proposes a guidance for the UV/Fe(II) synergistically activated sulfite.
研究领域:
环境科学
·
水处理技术
·
膜分离技术
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产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL RESEARCH
·
2024
·
IF 7.7
Bin Nie,Haojun Dong,Jincan Yan,Shengyu Zhang,Shuang Zhong
The activation of peroxymonosulfate (PMS) by heterogeneous catalysts presents an exciting but challenging strategy for degrading persistent organic pollutants in water. Iron oxychloride (FeOCl) is considered a promising heterogeneous catalyst due to its unique oxygen bridge structure, which could render it more active by facilitating the iron valence transitions between Fe(II) and Fe(III). However, the limited Fe(II)/Fe(III) conversion cycle rate hinders its catalytic activity, leading to unsatisfactory PMS activations in practical applications. Herein, we demonstrated the performance and the mechanistic pathway of enhanced FeOCl (CNFeOCl) catalytic activation using a graphitic carbon nitride (g-C 3 N 4 ) with a unique electronic structure as a carrier employing 2,4-dichlorophenol (2,4-DCP) as a representative pollutant. The CNFeOCl/PMS system achieved complete degradation of 2,4-DCP (30 mg/L) in a short time (<5 min), whereas the FeOCl/PMS system degraded only 35.98% under the same conditions. The high 2,4-DCP degradation rate of CNFeOCl was due to its improved Fe(II)/Fe(III) ratio (34.34%/40.03%), increased specific surface area (30.32 m 2 /g), and reduced charge-transfer resistance. Combining a series of characterizations, electron spin resonance (ESR) detection, and quenching experiments, the investigations elucidated the enhanced catalytic activation mechanism of CNFeOCl which includes dominant reactive oxygen species (ROS) generation and some key factors that generally affected the efficiency of oxidative degradation. We believe this study offers new insights into the intrinsic role of g-C 3 N 4 supported FeOCl for PMS activation and provides theoretical support to guide the rational design for developing efficient iron-based catalysts toward heterogeneous catalysis.
研究领域:
环境科学
·
催化化学
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产品关联
DOI
PubMed
高影响因子
Journal of Environmental Chemical Engineering
·
2025
·
IF 7.2
Yuting Zhang,Jiaqi Wang,Xuesong Zhang,Wenxiu Qin,Youbin Si
Preliminary studies have demonstrated that light can facilitate the biogeochemical cycling of iron, influencing the valence state of heavy metals, solidifying them, and ultimately achieving detoxification effects. However, few studies have focused on the oxidation of Sb(III) in different iron minerals and the differences in mechanisms. This study explored the photooxidation of Sb(III) in the presence of various iron minerals (hematite, pyrite and goethite), focusing on how different iron minerals influenced the oxidation process and the mechanisms involved. Among the minerals tested, pyrite exhibited exceptional photooxidation performance, achieving an Sb(III) oxidation efficiency of 67.03% after 300 minutes. This superior photooxidation activity correlated with pyrite’s significant Fe(II) yield (11.70 μg/L). Our study demonstrated that light irradiation enhanced Sb(III) oxidation through three iron-based minerals. Light exposure drove the generation of Fe(II) within these minerals, initiating Fe(II)/Fe(III) redox cycling. This process promoted reactive oxygen species (ROS) generation, including hydroxyl radicals (•OH), superoxide radicals (O 2 •− ) and hydrogen peroxide (H 2 O 2 ), which collectively mediated Sb(III) oxidation to the less toxic Sb(V). In the photooxidation of Sb(III), •OH played a critical role in reactions involving hematite and pyrite, while O 2 •− dominated in goethite and pyrite systems. H 2 O 2 was found to have a pivotal role across all three iron mineral systems. Additionally, photogenerated holes ( h + ) significantly enhanced Sb(III) oxidation in the pyrite system. This research highlighted the impact of light on the biogeochemical cycling of iron and its role in facilitating the oxidation of Sb(III) through reactions that involve photo-generated electrons and free radicals.
研究领域:
环境科学
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地球化学
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光催化
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生物地球化学
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环境化学
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产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2024
·
IF 12.2
Bin Zheng,Long Zhou,Chengjie Xue,Kuang Wang,Zhanqiang Fang
Oxalic acid-modified ball-milled zero-valent iron (OA-ZVI bm ) was employed to activate sodium chlorite (ClO 2 - ) for the removal of norfloxacin (NOR). The complete removal of 20 mg/L NOR was achieved within 60 min by the OA-ZVI bm /ClO 2 - process. Compared with the ZVI bm /ClO 2 - process which was the ball-milled zero-valent iron (ZVI bm ) activate sodium chlorite, the reaction activity of the OA-ZVI bm /ClO 2 - process was increased by 102.6 times. Through scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), electrochemical testing, and density functional theory (DFT) calculations, which has been confirmed that the introduction of oxalic acid can significantly increase the surface Fe(II) content of OA-ZVI bm , and accelerate the electron transfer rate of iron nuclei, thereby improve the efficiency of ClO 2 - activation for the removal of NOR. The role of various active species in NOR removal, which were •O 2 - , 1 O 2 , Fe(IV), ClO 2 , and •OH, was elucidated through free radical quenching experiments, electron paramagnetic resonance (EPR) spectroscopy, and quantitative detection of active species. These active species all participated in the reaction, while •O 2 - played a dominant role in the reaction because it could transform into other active species, such as (•OH, 1 O 2 ). Inorganic anions and natural organic matter have no significant effect on the removal of NOR in the OA-ZVI bm /ClO 2 - process. The protonation of oxalic acid ensured its good pH applicability range (pH = 2–11), thus exhibiting excellent performance in NOR removal in real water bodies. This further demonstrates that OA-ZVI bm prepared by oxalic acid ball milling modification is an efficient ClO 2 - activator, offering promising prospects for antibiotic removal technology.
研究领域:
环境科学
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水处理
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化学工程
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2019
·
IF 7.149
Xiao-Cheng Liu,Wen-Qiang Li,Yi-Ran Wang,Guan-Nan Zhou,Yi-Xuan Wang,Chuan-Shu He,Gong-Ming Wang,Yang Mu
Promotion of iron solubility using ligands is the preliminary step in the homogeneous electro-Fenton (EF) process at a mild pH, but the chelate efficiencies of most organic ligands are unsatisfactory, resulting in insufficient Fe(II) availability. In this study, atomic H* was, for the first time, introduced to the EF process to accelerate the regeneration of the Fe(II)-complex at a mild pH using a Ni-deposited carbon felt (Ni-CF) cathode. The introduction of atomic H* significantly elevated total organic carbon (TOC) abatement of ciprofloxacin (CIP) from 42% (CF) to 81% (Ni-CF) at a natural pH. In the presence of humic acids (HAs), atomic H* introduced via Ni-CF enhanced the CIP degradation rate to 10 times that of the CF at a mild pH. The electron spin resonance (ESR), density functional theory (DFT) calculations, electrochemical characterization, and in situ electrochemical Raman study clearly demonstrated that the atomic H* generated from the Ni-CF cathode was highly efficient at reducing Fe(III)-complexes at a natural pH. Additionally, the Ni-CF could generate atomic H* without significant nickel leaching. Thus, the atomic H* could continuously facilitate iron cycling and, consequently, enhance pollutant mineralization via the homogeneous EF process at a mild pH in an environmentally friendly manner.
研究领域:
环境科学
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化学工程
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水处理
·
电化学
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产品关联
DOI
PubMed
高影响因子
CHEMOSPHERE
·
2024
·
IF 8.1
Jie Zhang,Xufei Wang,Yiwei Liu,Tao Jin,Liang Liu,Xiaodong Ma,Gengbo Ren
The efficiency and stability of the electrical activation of persulfate (PS) by transition metal-based cathode are controlled by the cycling of Fe(III)/Fe(II) and the mass transfer of PS. In this study, the mixed-valence MOFs catalyst (Fe II -MIL-53(Fe)) modified flow-through cathode was prepared for the first time. Fe II -MIL-53(Fe) was prepared by replacing part of the iron-oxygen network structure in MIL-53(Fe) with Fe(II), resulting in the formation of coordinated unsaturated iron centers (CUICs). The increase of the Fe(III) CUICs facilitated the conversion of Fe(III) to Fe(II). Furthermore, the cycling of Fe(III)/Fe(II) was further promoted by the electric field. Meanwhile, the hydrodynamic behavior of flow-through cathode was indicated by the computational fluid dynamics (CFD) simulation. The quenching experiments and electron paramagnetic resonance (EPR) results showed that several reactive specie (SO 4 ·- , ·OH, O 2 ·- and 1 O 2 ) were produce. In summary, this work provided an effective strategy for the efficient and stable electrical activation of PDS.
研究领域:
环境科学
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化学工程
·
材料科学
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产品关联
DOI
PubMed
高影响因子
ACS Applied Nano Materials
·
2024
·
IF 5.3
Jie Huang,Xue Fan,Fei Yan,Jiyang Liu
Herein, we develop a simple electrochemical sensor based on the confinement effect of vertically ordered mesoporous silica film (VMSF) and the o-phenanthroline (Phen) chelating agent for ultrasensitive determination of ferrous ions (Fe2+). Fe(Phen)32+ obtained from the chelation between Fe2+ and Phen, shows higher electrochemical activity and larger geometric dimensions compared with free Fe2+, which could be effectively preconcentrated into the inner nanochannels of VMSF through spatial and electrostatic confinement effects. Differing from the conventional anodic stripping voltammetry, Fe(Phen)32+ could be enriched by convenient mechanical stirring and further detected by VMSF-modified indium tin oxide (VMSF/ITO), achieving an outstanding detection performance in terms of a linear range (1.0 nM–13.0 μM) and a limit of detection (LOD, 0.66 nM). Moreover, the established electrochemical sensor can accurately measure total iron and distinguish between different valence states (Fe2+ or Fe3+) with the help of reducing agents. Thanks to the outstanding antifouling ability of VMSF, the sensing platform consisting of VMSF/ITO and Phen chelating agent enables the precise determination of Fe2+ in complex real samples including tap water, pond water, FeSO4 tablets, and even colored samples, which can avoid the tedious sample pretreatment process and be applied in a wide range of scenarios.
研究领域:
分析化学
·
材料科学
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环境科学
·
电化学
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产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2019
·
IF 14.229
Qiangshun Wu,Hanpei Yang,Li Kang,Zhao Gao,Feifan Ren
In this work, a series of Fe-based metal-organic frameworks (Fe-MOFs) were synthesized and served as Fenton-like catalysts for tetracycline hydrochloride (TC–HCl) degradation. Herein, for the first time, we have demonstrated that visible light can accelerate Fe(II)/Fe(III) cycle in the photo-Fenton system based on iron-oxo (Fe-O) clusters in frameworks. Among these Fe-MOFs, MIL-101 possessed the highest activity mainly ascribed to its largest specific surface area and pore volume, and the most coordinatively unsaturated iron sites. The synergistic effect in the MIL-101/H 2 O 2 /visible light system was derived from the efficient separation and migration of photogenerated carriers. Due to the function of solid acid catalysts, MIL-101 extended effective pH range up to 10.2 and exhibited good reusability and stability. Hydroxyl radicals generated from H 2 O 2 coordinated at iron active sites were determined as the main reactive oxidative species and acceleration of Fe(II)/Fe(III) cycle was responsible for highly effective degradation of TC–HCl.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Jialong Yin,Heng Zhang,Mengfan Luo,Jia Zhao,Bingkun Huang,Pinji Chen,Zhenpeng Cai,Yue Yuan,Yang Liu,Chuanshu He,Bo Lai
The ferrous species (Fe(II))-periodate (PI) system employs efficient decontamination by generating ferryl species (Fe(IV)-oxo) under acidic pH conditions. However, the mechanisms by which the Fe(II)/PI system operates across a broad pH range remain elusive. In light of the rapid oxidation and consumption of Fe(II) at neutral pH, we developed an electro-Fe(II) system utilizing an iron plate anode to activate PI (E(Fe/C)/PI). Efficient sulfamethoxazole (SMX) degradation was achieved under the E(Fe/C)/PI system across a range of pH values. Quenching and chemical probe experiments revealed a transition from Fe(IV)-oxo to singlet oxygen ( 1 O 2 ) as the predominant reactive species from acidic to near-neutral pH, respectively. Density functional theory (DFT) calculations indicated that the differences in one-electron transfer capacity and hydrolysis pathways for various protonated Fe(IV)-oxo species underlie the variations in catalytic mechanisms. This study not only enhances the efficiency of the Fe(II)/PI system but also provides a comprehensive understanding of the activation mechanisms at different pH levels.
研究领域:
环境化学
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电化学
·
催化
·
水处理
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL GEOLOGY
·
2025
·
IF 3.6
Changjin Liang,Honghai Wu,Yaowei Li,Yufeng Guan
Ferrihydrite (Fh) can usually transform into phases with higher crystallinities. This may greatly alter Fh adsorption capacity for chromium ions, thereby affecting their immobilizations and fates. Foreign elements [e.g., lanthanum (La)] as impurities can become incorporated into Fh. Herein, the effect of La-substitution into Fh and the influence of the presence of Cr(VI) on Fh phase transformation and fate of Cr(VI) were investigated. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Electro-chemical impedance spectroscopy (EIS), and X-ray photoelectron spectroscopy (XPS) and other test methods were employed to probe phase changes after the Fe(II)-induced La-substituted Fh (La-Fh) transformations. At pH 5.5, no neoformed phase was observed until 7 d for La-Fh or pure Fh at 1 mM Fe(II) aq, but all La-Fh systems underwent transformations at 5 mM Fe(II)aq. A low pH and Fe(II)aq level favored lepidocrocite (Lp) to form, whereas goethite (Gt) was the predominant phase rather than Lp as pH increased to 7.2 with higher level Fe(II)aq. However, the La-substitution inhibits the La-Fh transformation rate and path. This made 5 % La-Fh transformed to Lp after 30 d at pH 7.2 and 1 mM Fe(II)aq. The La-release was present to some extent during the transformation process. Either the inhibition to La-Fh transformation or the La-slow release favors the retention of early-adsorbed Cr(VI) on iron-mineral surface. The added Cr(VI) might promote the La-Fh transformation even under a lower-level Fe(II), primarily attributed to the rapid reduction of Cr(VI) to Cr(III) by Fe(II), which produced more liable Fe(III) in addition to the Cr(III) that can improve the mineral conductivity, thereby enhancing the La-Fh transformation. Mechanisms responsible for the Fe(II)-induced La-Fh transformation companying the La slow-release are proposed to provide insights into the reduction and immobilization of Cr(VI) under anaerobic conditions, thus demonstrating that La-Fh is a promising material for application in Cr-contaminated site remediation.
研究领域:
环境化学
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地球化学
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土壤科学
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材料科学
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环境修复
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产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2024
·Vol. 48
·期 15
·6745-6757
·
IF 2.7
Yingzi Lin,Ningning Sun,Qingyu Zhang,Lei Chen,Shengbo Sun,Hong Yang,Jing Chen,Qixuan Weng,Shuang Xue
To overcome the limitations of the Fe(II)-activated percarbonate process for ACT removal, this study introduced cysteine as a complexing agent into the Fe(II)/SPC system and enhanced the degradation efficiency of ACT. Investigations were conducted on the effects of pH, temperature, common anions (Cl−, HCO3− and NO3−) in the water column, and humic acid (HA) on the degrading efficiency of the Cys/Fe(II)/SPC system. The results showed that under ideal conditions, 99.9% removal of ACT at 0.05 mM could be achieved. Alkaline environments inhibited ACT degradation, whereas acidic environments promoted it. Electron paramagnetic resonance (EPR) successfully detected ˙OH and O2˙−, but no 1O2 radical signal was detected. Further research was carried out to determine how much ˙OH and O2˙− contributed to the oxidation process. The results showed that both ˙OH and O2˙− contributed to the degradation of the ACT, with ˙OH's contribution being particularly significant. Mass spectrometry analysis was used to determine the structure of the oxidation products. Vulnerable sites in ACT were predicted using density functional theory. Using LC-MS/MS analysis, seven intermediates of the Cys/Fe(II)/SPC degradation of ACT were individually identified. The results showed that the acetylamino group on ACT and the C–N bond on the benzene ring are susceptible to attack by ˙OH. The T.E.S.T. toxicity prediction model was used to predict the toxicity of ACT and its intermediates. The results showed a trend towards reduced acute toxicity and overall developmental toxicity.
研究领域:
环境科学
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水处理
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化学工程
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分析化学
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毒理学
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产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2020
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IF 3.99
Qingwen Long,Feng Liu,Yanjie Yuan,Yuting Dai,Chunli Wang,Xuheng Li,Jing Zhang
In this study, heterogeneous Fenton-like catalyst, nano-Fe° encapsulated in hydrothermal carbon (Fe°/HTCC), was prepared via a green chemistry route, aiming at increasing the degradation efficiency of p-chlorophenol (4-CP) by controlling the stability of the catalyst and Fe(III)/Fe(II) cycling in the advanced oxidation process. The degradation of 4-CP by heterogeneous Fenton reactions was conducted with the assistance of visible light, which was monitored with the aid of the HPLC and total organic carbon analysis. The results revealed that Fe°/HTCC composite markedly enhanced both the degradation (100 %) and the mineralization efficiency (∼73.9 %) for 100 mg/L 4-CP within 60 min at pH 4.0. More importantly, the catalyst presented a high stability to resist the side oxidation, where the removal efficiency was maintained even after 5 successive cycling experiments. Electron spin resonance confirmed that in the presence of both HTCC and visible light irradiation greatly enhanced the production of •OH for the degradation and mineralization of 4-CP, which can be attributed to the enhancement of Fe(III)/Fe(II) cycling. This study paves a new way toward the rational design of Fe°–carbon composites as heterogeneous Fenton-like catalysts for potential applications into wastewater treatment.
研究领域:
环境科学
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化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）