CHEMOSPHERE
·
2022
·
IF 8.943
Jiayi Luo,Yunqiang Yi,Long Zhou,Zhanqiang Fang
The potassium-doped magnetic biochar (KMBC) preparation was inevitably introduced the different anions in the process of modifying magnetic biochar (MBC) with different potassium salts, but the effect and mechanism of different anion on KMBC activation properties has not been reported. Therefore, in this paper, five different KMBCs were prepared using several common potassium salts under the same dosage of K + and Fe 2+ , and then was added in the presence of persulfate (PS) for the removal of metronidazole (MNZ). The removal rate of metronidazole was ordered as KMBC K2SO4 (98.40%) > KMBC KNO3 (76.84%) > KMBC KCl (20.79%) > KMBC K2CO3 (19.02%) > KMBC K2C2O4 (14.23%). However, the semi-quantitative of Fe(II) experiments results confirmed that the effectively increase of Fe(II) content by potassium salts modification played the dominant role in improvement of KMBC activation performance. The Fe(II) content of KMBC were ordered as KMBC K2CO3 > KMBC K2SO4 > KMBC KNO3 > KMBC KCl > KMBC K2C2O4 , with the Fe(II) content of KMBC of 36.74, 17.70, 8.79, 5.24 and 4.85 mg/g, respectively. The indicated that the introduction of different anions would lead to different optimal Fe(Ⅱ) content in KMBC modified with different potassium salts, which was most directly reflected in 1 O 2 content in different KMBC/PS systems, and account for the difference in MNZ degradation efficiency. Meanwhile, when the Fe(II) content in KMBC reached the range of 13.7–28.8 mg/g, KMBC had the better performance of activating PS.
研究领域:
环境科学
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化学工程
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材料科学
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DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2019
·
IF 7.65
Zijun Dong,Chengchun Jiang,Jingxin Yang,Xi Zhang,Weili Dai,Pengwei Cai
This work investigates the transformation of iodide (I − ) by Fe(II)-activated peroxydisulfate (PDS). The transformation of I − into iodate (IO 3 − ) is a two-step process, involving reactive iodine species, such as hypoiodous acid (HOI), as a key intermediate, and IO 3 − as the final product. In the first step, SO 4 •- produced by Fe(II)-activated PDS is mainly responsible for the transformation of I − into HOI. In the second step, Fe(IV) formed by the reaction of Fe(III) with PDS is required, to facilitate the further oxidation of HOI to IO 3 − . The disproportionation of HOI and the oxidation by PDS alone contribute negligibly to IO 3 − formation. The IO 3 − yield increases to a maximum, before decreasing gradually, with increased PDS and Fe(II) dosages. The transformation of I − into IO 3 − is favored by lower pH and higher temperature, due to the greater SO 4 •- production by the reaction of Fe(II) with PDS under these conditions. Humic acid , as a representative natural organic matter, scavenges the formed HOI to form iodinated disinfection byproducts , which largely inhibit the transformation of I − into IO 3 − . In addition, the transformation of I − into IO 3 − and iodinated disinfection byproducts by Fe(II) activated PDS was confirmed in the natural waters.
研究领域:
环境化学
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水处理
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高级氧化过程
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DOI
PubMed
高影响因子
Chemical Engineering and Processing-Process Intensification
·
2019
·
IF 3.031
Ziye Zhao,Lei Wang,Jinmeng Fan,Yunhua Song,Guangwen Chu,Lei Shao
Rotor-stator reactor (RSR), a novel high-gravity device, was employed in the O 3 /persulfate (PS)/Fe 2+ process to enhance the degradation of indigo carmine (IC) in simulated wastewater. It was found that IC degradation efficiency increased with the increase of Fe 2+ concentration, RSR rotation speed, O 3 concentration and gas-liquid ratio, but decreased with the increase of IC concentration and temperature. When the rotation speed of RSR increased from zero to 1200 rpm, IC degradation efficiency increased from 25.6% to 64.2%. Because of the synergetic effects of the oxidative species (O 3 , OH, SO 4 − etc.), IC degradation efficiency in the O 3 /PS/Fe 2+ process was significantly higher than that in the O 3 or PS/Fe 2+ process. The high IC degradation efficiency can also be attributed to the good micromixing effect of the RSR. When the O 3 /PS/Fe 2+ process in the RSR was adopted before the sequencing batch reactor activated sludge process , both IC and COD degradation efficiencies increased significantly as a result of the improved biodegradability of the IC wastewater. Furthermore, a possible degradation mechanism of IC in the O 3 /PS/Fe 2+ process was proposed.
研究领域:
环境科学
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化学工程
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DOI
高影响因子
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
·
2021
·Vol. 2021
·期 38
·3992-3999
·
IF 2.524
Bing-Xue Luo,Yao Pan,Yin-Shan Meng,Qiang Liu,Jun Yin,Tao Liu,Yuan-Yuan Zhu
Graphical A magneto-fluorescent bifunctional Fe(II) complex is synthesized through decoration of the pyrene fluorophore to Fe(II)-pybox moiety. Its magnetic and fluorescent properties are characterized via X-ray structural analyses, magnetic susceptibility measurement, 57 Fe Mössbauer spectroscopy, and fluorescent spectroscopy. As expected, the coexistence of spin-crossover and fluorescence is achieved. The construction of magneto-fluorescent bifunctional complexes is a feasible approach toward multifunctional molecular materials. Herein we report the synthesis and properties studies of a mononuclear Fe(II) complex [Fe L 2 ](ClO 4 ) ( 1 ), where L is a pyridine-2,6-bis(oxazoline) (pybox) ligand decorated by the pyrene fluorophore. Magnetic susceptibility measurement of desolvated complex 1-d shows an incomplete and gradual spin-crossover in the temperature range 50–300 K, which is further confirmed via 57 Fe Mössbauer spectroscopy study. Light-induced excited spin state trapping (LIESST) is also observed below 70 K when the powder sample is irradiated by a 532 nm laser. The change in absorption during the spin-crossover (SCO) process is investigated via the temperature-dependent UV-vis spectroscopy. As expected, through introducing the chromophore, 1 displays fluorescence in both solution and solid state, achieving the coexistence of spin-crossover and fluorescence in one compound.
研究领域:
无机化学
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分子材料科学
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DOI
高影响因子
WATER RESEARCH
·
2020
·
IF 9.13
Panxin Wang,Xu He,Wei Zhang,Jun Ma,Jin Jiang,Zhuangsong Huang,Haijun Cheng,Suyan Pang,Yang Zhou,Xuedong Zhai
As a common animal feed additive, p-arsanilic acid (p-AsA) is thought to be excreted with little uptake and unchanged chemical structure, threatening the environment by potentially releasing more toxic inorganic arsenic. We herein investigated the removal of arsenic by in situ formed ferric (oxyhydr)oxides with the promotion of p-AsA degradation in Fe(II)/peroxydisulfate (PDS) system. Results showed that under acid conditions, p-AsA degraded very quickly and over 99% of p-AsA (5 μM) was degraded within 10 min at the optimal dosage of Fe(II) (100 μM) and PDS (150 μM) at pH 3, while less than 66.4% of arsenic was removed at pH 3–5. Higher pH (3–7) would inhibit the degradation of p-AsA but promote the arsenic removal. At pH 6–7, over 98.5% of total arsenic was removed, while the degradation efficiency of p-AsA was lower than 52.4%. HPLC-ICP-MS results indicated that the arsenic group was cleaved from p-AsA in the form of As(III) and then rapidly oxidized to As(V). FTIR and XPS analysis indicated that both As(V) products and residual p-AsA were bonded to ferric (oxyhydr)oxides via hydroxyl groups. Common cations (e.g., Na + , Ca 2+ , Mg 2+ ) and anions such as Cl − , SO 4 2− , CO 3 2− had no significant influence on arsenic removal, while SiO 3 2− , PO 4 3− and HA inhibited the removal of total arsenic, mainly by affecting the zeta potential of iron particles. In summary, the Fe(II)/PDS process, as an efficient method for partial oxidation and simultaneous adsorption of p-AsA under near-neutral conditions, is expected to control the potential environmental risks of p-AsA.
研究领域:
环境科学
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化学
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Lian Zhang,Yue Zhang,Xuyan Gao,Chunhua Xu
Recent studies showed that Fe(II) acts as the major electron donor when sulfidated zero-valent iron (S-ZVI) is used for reductive removal of pollutants. However, few studies have focused on the utilization efficiency and regeneration rate of Fe(II). In this work, the dynamic interaction between pH and S-ZVI for Cr(VI) removal and Fe(II) production was investigated at several pH levels. It was found that the maximum utilization efficiency and regeneration rate of Fe(II) was obtained at pH 5, which is consistent with the Cr(VI) removal by S-ZVI. To further study the role of Fe(II) in Cr(VI) reduction, an innovative binary correlation analysis between aqueous Cr(VI) and Fe(II) was applied with the addition of 1,10-phenanthroline as a way to control Fe(II) availability for Cr(VI) reduction. The analysis revealed that the Cr(VI) sequestration was initially controlled by Fe 0 /FeS and then by Fe(II), which accounts for the majority of the Cr(VI) sequestration. Additionally, the effects of several operational parameters (e.g., S/Fe ratio, S-ZVI dosage and initial concentration of Cr(VI)) on Cr(VI) removal were also evaluated and the results indicated that the removal of Cr(VI) exhibited a bimodal pattern with increasing S/Fe ratio, but followed a unimodal pattern with increase of S-ZVI dosage and chromium concentration. This study sheds additional insight into the dynamic interaction between pH and Fe(II), which is significant for further improving the efficiency of Fe(II) on contaminants.
研究领域:
环境科学
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化学工程
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DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2024
·
IF 7.4
Palanisamy Vasudhevan,Luo Shuhao,Zhang Ruoyu,Velu Manikandan,Dong Yu,Sandhanasamy Devanesan,Prakash Kumar Sarangi,Hui Ma,Saurav Dixit,Shengyan Pu
Chlorinated aromatic compounds are extremely dangerous, transmittable, and bioaccumulative. Ferrous-based persulfate stimulation methods are a potential approach for soil restoration, however they have limitations with ferrous accumulation. Citrate (CA) and ethylenediaminetetraacetic acid (EDTA) were used in the current investigation to enhance the efficiency of Fe(II)-activated persulfate (PS) reactions in the decomposition of 4-chlorophenol (4-CP) and 3-chlorobenzoic acid (3-CB) in soil. The combination of organic ligands with Fe(II) increased the overall iron content in the organic ligands/Fe(II)/PS systems and inhibited Fe(II) accumulation. Organic ligands absorbed Fe oxides in soil and facilitated to stimulate persulfate. The optimal concentration of organic ligands/Fe(II)/PS is 50:50:50, and around 74.11%, 70.05%, and 77.67%, 72.92% of the 4-CP and 3-CB were decomposed within 30 minutes, in contrast to 34.14% and 38.14% in the Fe(II)/PS system. The degradation percentage of 4-CP and 3-CB raised with increasing PS and Fe(II) levels, whereas high PS and Fe(II) concentrations prevented 4-CP and 3-CB degradation, most likely because of sulfate radical absorption. Furthermore, the 4-CP and 3-CB decomposition mediated by the citrate/Fe(II)/PS and EDTA/Fe(II)/PS systems were effective over a wide range of pH values (2.0–10). The organic ligands combined with Fe(II) catalyzed PS degradation showed a strong ability on enduring the effects of HCO3, Cl, and HA anions in soil on 4-CP and 3-CB decontamination. In addition, SO4 •- and OH • produced from citrate/Fe(II)/PS and EDTA/Fe(II)/PS systems were identified as the primary reactive oxygen species for 4-CP and 3-CB degradation. In conclusion, the organic ligands coupled with Fe(II) stimulated PS activation are potentially useful technique for the restoration of 4-CP and 3-CB contaminated soils.
研究领域:
环境科学
·
污染治理
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产品关联
DOI
高影响因子
GEOCHIMICA ET COSMOCHIMICA ACTA
·
2018
·
IF 4.69
Songhu Yuan,Xixiang Liu,Wenjuan Liao,Peng Zhang,Xiaoming Wang,Man Tong
Production of hydroxyl radicals ( OH) has been recently revealed upon oxygenation of sediments in redox-dynamic subsurface environments. In particular, Fe(II)-bearing clay minerals are the major sediment components contributing to OH production upon oxygenation, and the produced OH can oxidize contaminants and inactivate bacteria. Whereas, the mechanisms of OH production from oxygenation of Fe(II)-bearing clay minerals remain elusive. The objectives of this study were to identify the structural variation of Fe(II) entities during the oxidation of Fe(II)-bearing clay minerals by O 2 , and to unravel the mechanisms of electron transfer within the mineral structure and from mineral to O 2 for OH production. Nontronite (NAu-2, 23% Fe) which was chemically reduced to 54.5% Fe(II) in total Fe was used as a model Fe(II)-bearing clay mineral. Production of OH and oxidation of Fe(II) were measured during the oxidation of reduced NAu-2 by O 2 . A wide spectrum of spectroscopic techniques, including Fourier transform infrared spectroscopy (FTIR), Fe K-edge X-ray absorption spectroscopy (XAS), Mössbauer spectra, and X-ray photoelectron spectroscopy (XPS), were employed to explore the structural variation of Fe(II) entities in NAu-2 and the electron transfer within NAu-2 and from NAu-2 to O 2 . For 180 min oxidation of 1 g/L reduced NAu-2, a biphasic OH production was observed, being quick within the initial 15 min and slow afterwards. Production of OH correlates well with oxidation of Fe(II) in the reduced NAu-2. Within the initial 15 min, trioctahedral Fe(II)-Fe(II)-Fe(II) entities and edge Fe(II) in the reduced NAu-2 were preferentially and quickly oxidized, and electrons from the interior Fe(II)-Fe(II)-Fe(II) entities were most likely ejected from the basal siloxane plane to O 2 . Meanwhile, trioctahedral Fe(II)-Fe(II)-Fe(II) entities were mainly transformed to dioctahedral Fe(II)-Fe(II) entities. When the time of oxygenation was longer than 15 min, dioctahedral Al-Fe(II), Fe(II)-Fe(II) and Fe(II)-Fe(III) entities were slowly oxidized, and the interior electrons were transported through Fe(II)-O-Fe(III) linkages to edges and then ejected to O 2 . In the slow stage of oxidation, electrons from interior Fe(II) accumulated towards the near surface layers and fueled the regeneration of edge Fe(II) for OH production. In both stages, one-electron transfer mechanism with the involvement of O 2 − and H 2 O 2 applies for OH production from the oxidation of structural Fe(II) by O 2 . The mechanisms unraveled in this study advance the understanding of reactive oxygen species (ROS) production and structural Fe variation when Fe(II)-bearing clay minerals are oxygenated in redox-dynamic systems.
研究领域:
环境科学
·
矿物学
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产品关联
DOI
高影响因子
WATER RESEARCH
·
2021
·
IF 11.236
Jinbin Lin,Jing Zou,Hengyu Cai,Yixin Huang,Jiawen Li,Junyang Xiao,Baoling Yuan,Jun Ma
In this study, a commonly used reducing agent, hydroxylamine (HA), was introduced into Fe(II)/PAA process to improve its oxidation capacity. The HA/Fe(II)/PAA process possessed high oxidation performance for diclofenac degradation even with trace Fe(II) dosage (i.e., 1 μM) at pH of 3.0 to 6.0. Based on electron paramagnetic resonance technology, methyl phenyl sulfoxide (PMSO)-based probe experiments and alcohol quenching experiments, Fe IV O 2+ and carbon-centered radicals (R-O • ) were considered as the primary reactive species responsible for diclofenac elimination. HA accelerated the redox cycle of Fe(III)/Fe(II) and itself was gradually decomposed to N 2 , N 2 O, NO 2 − and NO 3 − , and the environmentally friendly gas of N 2 was considered as the major decomposition product of HA. Four possible degradation pathways of diclofenac were proposed based on seven detected intermediate products. Both elevated dosages of Fe(II) and PAA promoted diclofenac removal. Cl − , HCO 3 − and SO 4 2− had negligible impacts on diclofenac degradation, while humic acid exhibited an inhibitory effect. The oxidation capacity of HA/Fe(II)/PAA process in natural water matrices and its application to degrade various micropollutants were also investigated. This study proposed a promising strategy for improving the Fe(II)/PAA process and highlighted its potential application in water treatment.
研究领域:
环境科学
·
水处理技术
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产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2024
·
IF 7.7
Weisheng Dai,Yao Wang,Weijuan Guo,Guofu Wang,Muqing Qiu
The effects of Fe(II) and humic acid on U(VI) immobilization onto oxidized carbon nanofibers (Ox-CNFs, pyrolysis of bacterial cellulose) were investigated by batch, spectroscopic and modeling techniques, with results suggesting that, Ox-CNFs exhibited fast adsorption rate (adsorption equilibrium within 3 h), high adsorption performance (maximum adsorption capacity of 208.4 mg/g), good recyclability (no notable change after five regenerations) in the presence of Fe(II) towards U(VI) from aqueous solutions (e.g., 40 % reduction and 10 % adsorption at pH 8.0), which was attributed to the various oxygen-containing functional groups, excellent chemical stability, large specific surface area and high redox effect. U(VI) adsorption increased with increasing pH from 2.0 to 5.0, then high-level plateau and remarkable decrease were observed at 5.0–6.0 and at pH > 6.0, respectively. According to FT-IR and XPS analysis, a negative correlation between U(VI) reduction and organic in the presence of Fe(II) implied that U(VI) reduction was driven by Fe(II) while inhibited by humic acid. The interaction mechanism of U(VI) on Ox-CNFs was demonstrated to be adsorption and ion exchange at low pH and reduction at high pH according to XPS and surface complexation modeling. These findings filled the knowledge gaps pertaining to the effect of Fe(II) on the transformation and fate of U(VI) in the actual environment. This carbon material with distinctive performance and unique topology offers a potential platform for actual application in environmental remediation.
研究领域:
环境科学
·
材料科学
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DOI
PubMed
高影响因子
Polymers
·
2018
·Vol. 10
·期 9
·934
·
IF 2.935
Guangqian Zhu,Xianhui Zhang,Mengmeng Zhao,Liang Wang,Chuyang Jing,Peng Wang,Xiaowu Wang,Qinggang Wang
A series of iminopyridine complexes of Fe(II) and Co(II) complexes bearing fluorinated aryl substituents were synthesized for the polymerization of isoprene. The structures of complexes3a,2band3bwere determined by X-ray diffraction analysis. Complex3acontained two iminopyridine ligands coordinated to the iron metal center forming an octahedral geometry, whereas2badopted a chloro-bridged dimer, and3bfeatured with two patterns of cobalt centers bridged via chlorine atoms. Complexes2band3brepresented rare examples of chlorine bridged bimetallic Co(II) complexes. The fluorine substituents effects, particularly on catalytic activity and polymer properties such as molecular weight and regio-/stereo-selectivity were investigated when these complexes were employed for isoprene polymerization. Among the Fe(II)/methylaluminoxane (MAO) systems, the 4-CF3substituted iminopyridine Fe(II) complex1awas found as a highly active isoprene polymerization catalyst exhibiting the highest activity of 106g·(mol of Fe)−1·h−1. The resultant polymer displayed lower molecular weight (Mn= 3.5 × 104g/mol) and moderate polydispersity index (PDI = 2.1). Furthermore, the ratio ofcis-1,4-/3,4 was not affected by the F substituents. In the series of Co(II)/AlEt2Cl binary systems, complexes containing electron-withdrawing N-aryl substituents (R = 4-CF3, 2,6-2F) afforded higher molecular weights polyisoprene than that was obtained by the complex containing electron-donating N-alkyl substituents (R = octyl). However, ternary components system, complex/MAO/[Ph3C][B(C6F5)4] resulted in low molecular weight polyisoprene (Mn< 2000) with hightrans-1,4-unit (>95%).Keywords:iminopyridine ligands;Fe(II);Co(II) complexes;isoprene polymerization;fluorinated aryl substituents
研究领域:
有机金属化学
·
高分子科学
·
催化
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产品关联
DOI
PubMed
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2025
·
IF 21.1
Qingfei Zhao,Zhenpeng Guo,Zhuohan Wu,Shuyuan Dong,Ronghao Kang,Bingdian Jiang,Shuhui Guan,Ting Zhang,Zhenfeng Bian
The advanced oxidation process (AOP) based on hydroxyl radical ( • OH) has garnered increasing attention in water purification and wastewater treatment. However, producing • OH by activating hydrogen peroxide (H 2 O 2 ) encounters the challenges associated with the sluggish kinetics of Fe(II) regeneration. Herein, we developed a carambola-like catalyst of boron (B)-doped TiO 2 mesocrystals-based iron catalyst (Fe-B-MST), which served as a photocatalyst to modulate the regeneration of Fe(II) in photo Fenton-like systems. We successfully used the electrospinning method to gain membrane and realised the remediation of different industrial wastewater. The Fe-B-MST catalyst exhibits excellent efficiencies in the oxidative degradation of 4-chlorophenol (4-CP) pollutants, effectively facilitating the production of • OH while minimising the formation of toxic byproducts, with the first-order kinetic constant ( k = 2.372 min −1 ) being approximately 6.1 times greater than that without B doping, and 19.8 times greater than that observed with commercial TiO 2 . Theoretical calculations and related physicochemical characterisation reveal that B occupies an interstitial site in titania, conferring a sufficiently high valence band potential, making it thermodynamically favourable for H 2 O 2 oxidation and weakening its interaction with • OH, consequently increasing higher reactivity toward the targeted organic pollutant. The B doping facilitates electron transfer, promotes rapid reduction of Fe(III) to Fe(II), and further enhances • OH production via a photo Fenton-like reaction. The oxidation reaction stoichiometry efficiencies were quantified for different organics and calculated to be in the range of 7.70–24.20 % in Fe-B-MST/H 2 O 2 vis. system, representing an enhancement of 1.18–1.54 times compared to Fe-MST/H 2 O 2 vis. , alongside the utilisation efficiency of H 2 O 2 ( η ) of Fe-B-MST/H 2 O 2 vis. is 1.37–1.67 fold greater than that of Fe-MST/H 2 O 2 vis. after 30 min of reaction. This study expands our understanding and provides valuable insights into applying photocatalysis for enhanced wastewater treatment.
研究领域:
环境科学
·
材料科学
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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）