Absorption of lean formaldehyde from air with Na2SO3 solution

Jiao, Zhen; Luo, Peicheng; Wu, Youting; Ding, Shi; Zhang, Zhibing

doi:10.1016/j.jhazmat.2005.10.044

Cited by 23 publications

(7 citation statements)

References 12 publications

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“…Activated carbon, molecular sieve and silica gel are porous materials with a large surface area medium for physical and chemical adsorption. The common absorbents contain inorganic salts (e.g., ammonium and sulfurous) and are composed with amine groups such as urea and its derivatives, hydrazine, and amino-containing polymers [71,72,73]. Physical adsorption involves VOCs being trapped onto the materials such as zeolites, activated carbon, activated alumina and molecular sieves and porous clay ore without changing their original form.…”

Section: Traditional Removal Approachesmentioning

confidence: 99%

Removal of Indoor Volatile Organic Compounds via Photocatalytic Oxidation: A Short Review and Prospect

et al. 2016

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Volatile organic compounds (VOCs) are ubiquitous in indoor environments. Inhalation of VOCs can cause irritation, difficulty breathing, and nausea, and damage the central nervous system as well as other organs. Formaldehyde is a particularly important VOC as it is even a carcinogen. Removal of VOCs is thus critical to control indoor air quality (IAQ). Photocatalytic oxidation has demonstrated feasibility to remove toxic VOCs and formaldehyde from indoor environments. The technique is highly-chemical stable, inexpensive, non-toxic, and capable of removing a wide variety of organics under light irradiation. In this paper, we review and summarize the traditional air cleaning methods and current photocatalytic oxidation approaches in both of VOCs and formaldehyde degradation in indoor environments. Influencing factors such as temperature, relative humidity, deactivation and reactivations of the photocatalyst are discussed. Aspects of the application of the photocatalytic technique to improve the IAQ are suggested.

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Section: Traditional Removal Approachesmentioning

confidence: 99%

Removal of Indoor Volatile Organic Compounds via Photocatalytic Oxidation: A Short Review and Prospect

et al. 2016

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“…32 The properties of this molecule in the ground state using ab initio studies were reviewed by Bruna et al 33 Besides, Alvarez-Idaboy et al and Zhao et al explored the reaction between H 2 CO and the radical OH. 34,35 In the present article, different mechanisms for the hemiacetal formation from formaldehyde and methanol have been studied (Figure 1). Initially, the reaction between the isolated reactants has been considered (i).…”

Section: ■ Introductionmentioning

confidence: 99%

Mechanisms of Formation of Hemiacetals: Intrinsic Reactivity Analysis

et al. 2012

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The reaction mechanism of the hemiacetal formation from formaldehyde and methanol has been studied theoretically at the B3LYP/6-311++G(d,p) level. In addition to the study of the reaction between the isolated reactants, three different kinds of catalysis have been explored. The first one examines the use of assistants, especially bridging water molecules, in the proton transfer process. The second one attempts to increase the local electrophilicity of the carbon atom in formaldehyde with the presence of a Brønsted acid (H(+) or H(3)O(+)). The last one considers the combined effect of both catalytic strategies. The reaction force, the electronic chemical potential, and the reaction electronic flux have been characterized for the reaction path in each case. In general, it has been found that structural rearrangements represent an important energetic penalty during the activation process. The barriers for the reactions catalyzed by Brønsted acids show a high percentage of electronic reorganization contribution. The catalytic effects for the reactions assisted by water molecules are due to a reduction of the strain in the transition state structures. The reaction that includes both acid catalysis and proton assistance transfer shows the lowest energy barrier (25.0 kJ mol(-1)).

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“…Activated carbon, molecular sieve and silica gel are porous materials with a large surface area medium for physical and chemical adsorption. The common absorbents contain inorganic salts (e.g., ammonium and sulfurous) and are composed with amine groups such as urea and its derivatives, hydrazine, and amino-containing polymers [23,24]. Catalytic oxidation technology with thermal treatment is another effective method for VOCs removal.…”

Section: Introductionmentioning

confidence: 99%

Decontamination of Toxic Volatile Organic Compounds in Charcoal Processed from <i>Erythrophleum guineense</i> (Sassy Wood)

Gushit¹,

Habila²

2020

JCEBE

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The work aimed at decontaminating potentially toxic compounds found in the charcoal sample, started with collecting the sample of charcoal processed from Erythrophleum guineense (Sassy wood) established in an earlier work to be emitting toxic compounds. The sample was subjected to combustion in a chamber and the volatiles organic compounds (VOCs), formaldehyde (HCHO) and other air quality parameters detected from the hot smoke emitted using the Air Pollutant Detector (Air Master). The VOCs and HCHO average concentration of 2.98mg/m 3 and 1.27mg/m 3 respectively were detected in the sample, giving indication of extremely high concentration beyond standard permissible limits. The decontaminants which includes; CaO, NaCl, KOH, NaCl/CaO (1:1) and Al 2 O 3 were prepared by dissolving pulverized portion of each in a small amount of distilled water and diluted with purified dual-purpose kerosene (DPK), after which each solution was uniformly sprayed on the pre-weighed charcoal in the combustion chamber. On applying the prepared decontaminants: CaO, NaCl, KOH, NaCl/CaO and Al 2 O 3 on the charcoal, the VOCs concentration of 0.32mg/m 3 , 0.60mg/m 3 , 0.61 mg/m 3 , 1.11 mg/m 3 and 2.88mg/m 3 respectively were detected, which showed significant reduction in the concentration of the VOCs emitted that is far below the WHO limits for short term exposure of 0.1 mg/ m 3 , indicating that using the decontaminants is required if such charcoals must continue to be used. The VOCs were characterized in all the samples after they were adsorbed, desorbed, extracted, purified, concentrated and finally detected using the Gas chromatography Mass Spectrometry (GC-MS). The VOCs detected are; Octadecanoic, n-hexadecenoic acid, levomenthol acid and cyclobutanol acid widely reported to be toxic. Therefore, the work recommends that charcoal fires should not be ignited and used in enclosures, and appropriate Government regulatory agencies should create awareness on the need to avoid the use of Erythrophleum guineense (sassy wood) charcoal. If it must be used, decontaminant like CaO prepared from this work should be used since it is a cheap and accessible waste material found in auto mechanic garages indiscriminately discarded by gas welders.

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Absorption of lean formaldehyde from air with Na2SO3 solution

Cited by 23 publications

References 12 publications

Removal of Indoor Volatile Organic Compounds via Photocatalytic Oxidation: A Short Review and Prospect

Removal of Indoor Volatile Organic Compounds via Photocatalytic Oxidation: A Short Review and Prospect

Mechanisms of Formation of Hemiacetals: Intrinsic Reactivity Analysis

Decontamination of Toxic Volatile Organic Compounds in Charcoal Processed from <i>Erythrophleum guineense</i> (Sassy Wood)

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Absorption of lean formaldehyde from air with Na2SO3 solution

Cited by 23 publications

References 12 publications

Removal of Indoor Volatile Organic Compounds via Photocatalytic Oxidation: A Short Review and Prospect

Removal of Indoor Volatile Organic Compounds via Photocatalytic Oxidation: A Short Review and Prospect

Mechanisms of Formation of Hemiacetals: Intrinsic Reactivity Analysis

Decontamination of Toxic Volatile Organic Compounds in Charcoal Processed from &lt;i&gt;Erythrophleum guineense&lt;/i&gt; (Sassy Wood)

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Decontamination of Toxic Volatile Organic Compounds in Charcoal Processed from <i>Erythrophleum guineense</i> (Sassy Wood)