New evidence of the effect of the chemical structure of activated carbon on the activity to promote radical generation in an advanced oxidation process using hydrogen peroxide

Vega, Esther; Váldes, Héctor

doi:10.1016/j.micromeso.2017.09.018

Cited by 41 publications

(13 citation statements)

References 44 publications

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“…The deposited TiO 2 is responsible for efficiently decomposing the ozone, producing HO • radicals. Other properties, such as pore volume, porosity, pore size distribution, and, particularly, the presence of active sites on the surface (e.g., Lewis acid sites, which are responsible for the catalytic reactions), may be responsible for this increase in k oxS [45]. Acidity or basicity, for example, is key to surface properties.…”

Section: Evaluation Of Operating Conditions For Model Validationmentioning

confidence: 99%

“…Furthermore, the hydroxyl groups, which are present on all surfaces of the metal oxides, are dependent on the deposited metal oxide [39]. Valdés and Vega [45] studied the effect of the chemical structure of various active carbons on the catalytic activity for the generation of hydroxyl radicals, where they suggested that the presence of iron metal ions played an important role in the decomposition of ozone and hydrogen peroxide towards the generation of radicals. Those carbons with more basic surface functionalities led to a higher radical generation and, consequently, to a higher catalytic activity.…”

Section: Evaluation Of Operating Conditions For Model Validationmentioning

confidence: 99%

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Heterogeneous Catalytic Ozonation of Aniline-Contaminated Waters: A Three-Phase Modelling Approach Using TiO2/GAC

Ferreiro

Villota

Lombraña

et al. 2020

Water

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This work aims to study the sustainable catalytic ozonation of aniline promoted by granular active carbon (GAC) doped with TiO2. Aniline was selected as a model compound for the accelerator manufacturing industries used in the manufacture of rubber due to its environmental impact, low biodegradability, and harmful genotoxic effects on human health. Based on the evolution of total organic carbon (TOC), aniline concentration measured using high performance liquid chromatography (HPLC), pH and ozone concentration in liquid and gas phase, and catalyst loading, a three-phase reaction system has been modelled. The proposed three-phase model related the ozone transfer parameters and the pseudo-first order kinetic constants through three coefficients that involve the adsorption process, oxidation in the liquid, and the solid catalyst. The interpretation of the kinetic constants of the process allowed the predominance of the mechanism of Langmuir–Hinshelwood or modified Eley–Rideal to be elucidated. Seven intermediate aromatic reaction products, representative of the direct action of ozone and the radical pathway, were identified and quantified, as well as precursors of the appearance of turbidity, with which two possible routes of degradation of aniline being proposed.

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Section: Evaluation Of Operating Conditions For Model Validationmentioning

confidence: 99%

Section: Evaluation Of Operating Conditions For Model Validationmentioning

confidence: 99%

Heterogeneous Catalytic Ozonation of Aniline-Contaminated Waters: A Three-Phase Modelling Approach Using TiO2/GAC

Ferreiro

Villota

Lombraña

et al. 2020

Water

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“…44,45 After modification by hydrogen peroxide, the PAC functional groups that promote radical generation were reduced, so the O-T-RAC could inhibit the pore internal oxidative coupling reaction the best. 46 Moreover, the absorbed APAP in the SPAC can polymerize into multimers such as Z4 and Z5 and even with higher polymerization degree, as shown in Figure 6. Multimers with larger molecular size will be difficult to desorb in the pores of activated carbon, which can block the channel structure, and the increasing boiling point and decomposition temperature of the polymers lead to difficulty of desorption even in the thermal regeneration under 1200 °C.…”

Section: Table 1 Content Of Oxygen Surface Functional Groups In T-rac...mentioning

confidence: 99%

Practical and Sustainable Modification Method on Activated Carbon to Improve the Decolorization Process in the Acetaminophen Pharmaceutical Industry

Liu

Cheng

et al. 2021

ACS Omega

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Decolorization plays an important part in the industrial production of acetaminophen (APAP) drugs. The impurities generated from the APAP pharmaceutical industry decolorization refining process were primarily separated and purified, and their structures were determined by MS and 1 H NMR technology. Then the catalytic effects of three samples of modified powdered activated carbon (PAC) on APAP in heterogeneous solution systems and the adsorption catalysis system were systematically investigated, which indicated that PAC catalyzed the APAP oxidative coupling side reaction and thus increased the impurities in the APAP product. The M-T-RAC (thermal regeneration PAC modified by ammonium sulfate) possessing more acidic surface groups can effectively inhibit this side reaction. Furthermore, according to the different catalytic results of O-T-RAC (thermal regeneration PAC modified by hydrogen peroxide) in solid−liquid catalytic and adsorption catalytic systems, we speculated that the multimer impurities were generated by the oxidative coupling reaction of APAP being oxidized to rated N-acetyl-p-benzoquinone (NAPQI) during decolorization, while free radical polymerization of APAP mainly occurred in the pores of the spent PAC. The pore textural structure and chemical properties of M-T-RAC were further characterized to ensure its feasibility of industrial application. The process of simulating industrial decolorization substantiated the excellent ability of M-T-RAC to inhibit side reactions. This study contributes to the development of green materials for sustainable recycling of activated carbon to reduce pollution and costs, and provides an effective advice for the pharmaceutical process.

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“…Carbon-based materials display several advantages in oxidative processes. Their ability to form oxidizing species (such as hydroxyl radicals) from oxidant sources (such as hydrogen peroxide) has been widely studied [58][59][60][61][62]. They are proven catalysts for oxidation reactions in the liquid phase, either as catalysts on their own or in hybrid forms, such as in water and wastewater remediation [63][64][65][66][67].…”

Section: Oxidative Desulfurization (Ods) and Denitrogenation (Odn)mentioning

confidence: 99%

Carbon-Based Materials for Oxidative Desulfurization and Denitrogenation of Fuels: A Review

et al. 2021

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Sulfur (S) and nitrogen (N) are elements naturally found in petroleum-based fuels. S- and N-based compounds in liquid fuels are associated with a series of health and environmental issues. Thus, legislation has become stricter worldwide regarding their content and related emissions. Traditional treatment systems (namely hydrodesulfurization and hydrodenitrogenation) fail to achieve the desired levels of S and N contents in fuels without compromising combustion parameters. Thus, oxidative treatments (oxidative desulfurization–ODS, and oxidative denitrogenation-ODN) are emerging as alternatives to producing ultra-low-sulfur and nitrogen fuels. This paper presents a thorough review of ODS and ODN processes applying carbon-based materials, either in hybrid forms or as catalysts on their own. Focus is brought to the role of the carbonaceous structure in oxidative treatments. Furthermore, a special section related to the use of amphiphilic carbon-based catalysts, which have some advantages related to a closer interaction with the oily and aqueous phases, is discussed.

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New evidence of the effect of the chemical structure of activated carbon on the activity to promote radical generation in an advanced oxidation process using hydrogen peroxide

Cited by 41 publications

References 44 publications

Heterogeneous Catalytic Ozonation of Aniline-Contaminated Waters: A Three-Phase Modelling Approach Using TiO2/GAC

Heterogeneous Catalytic Ozonation of Aniline-Contaminated Waters: A Three-Phase Modelling Approach Using TiO2/GAC

Practical and Sustainable Modification Method on Activated Carbon to Improve the Decolorization Process in the Acetaminophen Pharmaceutical Industry

Carbon-Based Materials for Oxidative Desulfurization and Denitrogenation of Fuels: A Review

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