Effect of mesoporous silica molecular sieve coating on nZVI for 2,4-DCP degradation: Morphology and mechanism during the reaction

Wan, Junjie; Feng, Xin; Yu, Li; He, Jinqiang; Zhao, Na; Liu, Zhifeng; Lin, Yangming; Chen, Yang; Liang, Wanqi

doi:10.1016/j.cep.2018.11.011

Cited by 25 publications

(4 citation statements)

References 33 publications

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“…To investigate the degradation pathway of 2,4-DCP in the 0.15Co-SiOx/PMS system, the GC–MS technique (Figure S3) was used to detect the intermediates. Various aromatics and aliphatic compounds such as 4-chlorocatechol, 2-chlorohydroquinine, p -chlorophenol, 2-chlorophenol, hydroquinone, phenol, catechol, benzoquinone, 2-chlorobenzoquinone, 2,4-dichlororesorcinol, 4,6-dichlororesorcinol, 3,5-dichlorocatechol, oxalic acid, and acetic acid were detected as the degradation intermediates. − Thus, the degradation pathway of 2,4-DCP was proposed as shown in Figure . The pathway (1) reveals that the chlorines at the position numbers 2 and 4 on 2,4-DCP were attacked by SO 4 •– , OH • , 1 O 2 , and O 2 •– to produce p -chlorophenol and 2-chlorophenol and further produce hydroquinone, phenol, and catechol .…”

Section: Resultsmentioning

confidence: 99%

Uniform Mesoporous Amorphous Cobalt-Inherent Silicon Oxide as a Highly Active Heterogeneous Catalyst in the Activation of Peroxymonosulfate for Rapid Oxidation of 2,4-Dichlorophenol: The Important Role of Inherent Cobalt in the Catalytic Mechanism

Lian

Roy

Kizilkaya

et al. 2020

ACS Appl. Mater. Interfaces

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Amorphous cobalt-inherent silicon oxide (Co-SiOx) was synthesized for the first time and employed as a highly active catalyst in the activation of peroxymonosulfate (PMS) for the rapid oxidation of 2,4-dichlorophenol (2,4-DCP). The characterization results revealed that the 0.15Co-SiOx possessed a high specific surface area of 607.95 m 2 /g with a uniform mesoporous structure (24.33 nm). The X-ray diffraction patterns indicate that the substituted cobalt atoms enlarge the unit cell parameter of the original SiO 2 , and the selected area electron diffraction pattern confirmed the amorphous nature of Co-SiOx. More bulk oxygen vacancies (O v ) existing in the Co-SiOx were identified to be one of the primary contributors to the significantly enhanced catalytic activation of PMS. The cobalt substitution both creates and stabilizes the surficial O v and forms the adequately active Co(II)−O v pairs which engine the electron transfer process during the catalytic activities. The active Co(II)−O v pairs weaken the average electronegativity of Co/Si and Co/O sites, resulting in the prevalent changes in final state energy, which is the main driving cause of the binding energy shifts in the X-ray photoelectron spectroscopy (XPS) spectra of Si and O among all samples. The increase of the relative proportion of Co(III) in the spent Co-SiOx probably causes the binding energy shifts of the Co XPS spectrum compared to that of the Co-SiOx. The amorphous Co-SiOx outperforms stable and quick 2,4-DCP degradation, achieving a much higher kinetic rate of 0.7139 min −1 at pH = 7.02 than others via sulfate radical advanced oxidation processes (AOPs), photo-Fenton AOPs, H 2 O 2 reagent AOPs, and other AOP approaches. The efficient degradation performance makes the amorphous Co-SiOx as a promising catalyst in removing 2,4-DCP or organic-rich pollutants.

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Section: Resultsmentioning

confidence: 99%

Uniform Mesoporous Amorphous Cobalt-Inherent Silicon Oxide as a Highly Active Heterogeneous Catalyst in the Activation of Peroxymonosulfate for Rapid Oxidation of 2,4-Dichlorophenol: The Important Role of Inherent Cobalt in the Catalytic Mechanism

Lian

Roy

Kizilkaya

et al. 2020

ACS Appl. Mater. Interfaces

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“…Recently, nanoremediation based on nano zero-valent iron (nZVI) has attracted increasing attention due to its environmental friendliness, high efficiency, and wide applications [9]. nZVI has been used to reduce leaching of toxic metals through adsorption, complexation and chemical reduction processes [10][11][12][13][14][15][16]. Numerous studies have reported applications of nZVI in the remediation of soils contaminated with Cr [17][18][19][20] as well as other toxic metals [14][15][16] and organic contaminants [21].…”

Section: Introductionmentioning

confidence: 99%

Remediation of Cr(VI)-Contaminated Soil by Nano-Zero-Valent Iron in Combination with Biochar or Humic Acid and the Consequences for Plant Performance

Sun

Zheng

Wang

et al. 2020

Toxics

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Nano-scale zero-valent iron (nZVI) is among the most common nanoparticles widely used for the treatment of various environmental contaminants. However, little is known about the combined effects of nano-zero-valent iron (nZVI) and other soil amendments on soil remediation and plant performance. For the first time, we studied the remediation of Cr(VI)-contaminated soil using bare nZVI (B-nZVI) and starch-supported nZVI (S-nZVI) in combination with either biochar (BC) or humic acid (HA), and the consequent effects on plant growth and Cr accumulation. Both S-nZVI and B-nZVI decreased the contents of Cr(VI) and available Cr in soil, but increased available Fe content, with S-nZVI generally showing more pronounced effects at a higher dose (1000 mg/kg). B-nZVI exerted no inhibition and even stimulation on plant growth, but 1000 mg/kg S-nZVI produced significant phytotoxicity, resulting in decreased plant growth, low chlorophyll content in leaves, and excessive accumulation of Fe in roots. Each nZVI decreased shoot and root Cr concentrations. BC and HA produced synergistic effects with nZVI on Cr(VI) removal from soil, but HA decreased soil pH and increased the availability of Cr and Fe, implying a potential environmental risk. Addition of BC or HA did not alter the effects of either nZVI on plant growth. In conclusion, combined application of 100 mg/kg nZVI and BC could be an ideal strategy for the remediation of soil contaminated with Cr(VI), whereas high-dose S-nZVI and HA are not recommended in the remediation of agricultural soils for crop production or in the phytostabilization of Cr(VI).

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“…In order to address these drawbacks, researchers have attempted to stabilize and disperse NZVI particles with the following method: 1) offering a support for NZVI particles, such as kaolinite [17], bentonite [18], activated carbon [19,20], mesoporous carbon [21], and mesoporous silica [22]; 2) changing the surface properties of NZVI with surfactant [23], polyelectrolyte, or nature biopolymer [24]. Most solid supports cannot be used to control stability and nanometer distribution of the NZVI particles.…”

Section: Introductionmentioning

confidence: 99%

The Influence of Pluronic F-127 Modification on Nano Zero-Valent Iron (NZVI): Sedimentation and Reactivity with 2,4-Dichlorophenol in Water Using Response Surface Methodology

Zhang

Jing

et al. 2020

Catalysts

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Nano zero-valent iron (NZVI) is widely used for reducing chlorinated organic pollutants in water. However, the stability of the particles will affect the removal rate of the contaminant. In order to enhance the stability of nano zero-valent iron (NZVI), the particles were modified with F-127 as an environmentally friendly organic stabilizer. The study investigated the effect of the F-127 mass ratio on the colloidal stability of NZVI. Results show that the sedimentation behavior of F-NZVI varied at different mass ratios. A biphasic model was used to describe the two time-dependent settling processes (rapid sedimentation followed by slower settling), and the settling rates were calculated. The surface morphology of the synthesized F-NZVI was observed with a scanning electron microscope (SEM), and the functional groups of the samples were analyzed with Fourier Transform Infrared Spectroscopy (FTIR). Results show that the F-127 was successfully coated on the surface of the NZVI, and that significantly improved the stability of NZVI. Finally, in order to optimize the removal rate of 2,4-dichlorophenol (2,4-DCP) by F-NZVI, three variables were tested: the initial concentration 2,4-DCP, the pH, and the F-NZVI dosage. These were evaluated with a Box-Behnken Design (BBD) of response surface methodology (RSM). The experiments were designed by Design Expert software, and the regression model of fitting quadratic model was established. The following optimum removal conditions were determined: pH = 5, 3.5 g·L−1 F-NZVI for 22.5 mg·L−1 of 2,4-DCP.

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Effect of mesoporous silica molecular sieve coating on nZVI for 2,4-DCP degradation: Morphology and mechanism during the reaction

Cited by 25 publications

References 33 publications

Uniform Mesoporous Amorphous Cobalt-Inherent Silicon Oxide as a Highly Active Heterogeneous Catalyst in the Activation of Peroxymonosulfate for Rapid Oxidation of 2,4-Dichlorophenol: The Important Role of Inherent Cobalt in the Catalytic Mechanism

Uniform Mesoporous Amorphous Cobalt-Inherent Silicon Oxide as a Highly Active Heterogeneous Catalyst in the Activation of Peroxymonosulfate for Rapid Oxidation of 2,4-Dichlorophenol: The Important Role of Inherent Cobalt in the Catalytic Mechanism

Remediation of Cr(VI)-Contaminated Soil by Nano-Zero-Valent Iron in Combination with Biochar or Humic Acid and the Consequences for Plant Performance

The Influence of Pluronic F-127 Modification on Nano Zero-Valent Iron (NZVI): Sedimentation and Reactivity with 2,4-Dichlorophenol in Water Using Response Surface Methodology

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