Oxidation of potassium n -butyl xanthate with ozone: Products and pathways

Yan, Pingfang; Chen, Gangquan; Ye, Maoyou; Sun, Shuiyu; Ma, Hui; Lin, Weixiong

doi:10.1016/j.jclepro.2016.08.027

Cited by 40 publications

(18 citation statements)

References 15 publications

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“…It was revealed that only a small fraction of carbon in thiol collectors was completely mineralized by O 3 , although all of the above 90% of collectors were decomposed. In the ozonation of n-butyl xanthate, n-butanol was detected by UPLC/Q-TOF-MS [32], and O-butyl peroxydithiocarbonate was found [11]. Thus, it could be reasonably inferred that most organic carbon in thiol collectors were still in the forms of reductive organic intermediates, after the ozonation.…”

Section: Carbon and Sulfur Mineralization Of Thiol Collectorsmentioning

confidence: 96%

“…As volatile sulfur species such as CS 2 and H 2 S were generated, they may have been emitted from ozone-bubbled solutions into a gas phase, resulting in lower γ S values. For example, Yan et al [32] had inferred the emitting of 20.6% sulfur into the gas phase in decomposing n-butyl xanthate by O 3 . Generally, in this work, the mineralization ratio of carbon and sulfur for the four collectors ranged from 10% to 27%, at the collector removal ratio of above 90%.…”

Section: Carbon and Sulfur Mineralization Of Thiol Collectorsmentioning

confidence: 99%

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Degradation of Thiol Collectors Using Ozone at a Low Dosage: Kinetics, Mineralization, Ozone Utilization, and Changes of Biodegradability and Water Quality Parameters

Lin

et al. 2018

Minerals

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Ozonation at a high O3 dosage can achieve high efficiencies in removing flotation reagents but it has a low ozone-utilization rate. The ozonation of potentially toxic thiol collectors (potassium ethyl xanthate (EX), sodium diethyl dithiocarbamate (SN-9), O-isopropyl-N-ethyl thionocarbamate (Z-200) and dianilino dithiophoshoric acid (DDA)) was investigated in an ozone-bubbled reactor at a low O3 dosage of 1.125 mg/(min·L). The degradation kinetics, mineralization, ozone utilization, changes of biodegradability, and water quality parameters were studied, and the degradation behaviors of four collectors were compared. Thiol collectors could be effectively degraded with a removal ratio of >90% and a mineralization ratio of 10‒27%, at a low O3 dosage. The ozonation of thiol collectors followed the pseudo first-order kinetics, and rate constants had the order of kSN-9 > kEX > kZ-200 > kDDA. The Z-200 and DDA were the refractory flotation reagents treated in the ozonation process. After ozonation, the biodegradability of EX, SN-9, and DDA solutions was remarkably raised, but the biodegradability of Z-200 only increased from 0.088 to 0.15, indicating that the Z-200 and its intermediates were biologically persistent organics. After ozonation, the solution pH decreased from 10.0 to 8.0‒9.0, and both the conductivity and oxidation-reduction potential increased. The ozone utilization ratio in decomposing thiol collectors was above 98.41%, revealing almost complete usage of input O3. The results revealed that thiol collectors could be effectively degraded by O3, even at a low dosage, but their degradation behaviors were quite different, due to intrinsic molecular properties.

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Section: Carbon and Sulfur Mineralization Of Thiol Collectorsmentioning

confidence: 96%

Section: Carbon and Sulfur Mineralization Of Thiol Collectorsmentioning

confidence: 99%

Degradation of Thiol Collectors Using Ozone at a Low Dosage: Kinetics, Mineralization, Ozone Utilization, and Changes of Biodegradability and Water Quality Parameters

Lin

et al. 2018

Minerals

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“…In the direct reaction, molecular ozone reacts with organic contaminants, whereas in the indirect reaction, organic pollutants are oxidized by highly reactive free radicals derived from the decomposition of molecular ozone [23][24][25]. Some catalytic ozonation processes (COPs) have been reported on single ozonation processes (SOPs) [26]. COP was proposed to be more effectively convert ozone into free radicals [27,28].…”

Section: Parameters Influencing Cod Degradationmentioning

confidence: 99%

“…However, many of them are toxic (biphenyl A, hydroquinone, methanol, etc). It also contains some hydrocarbons and carboxylic acids [26]. HO· can decompose most of these substrates efficiently, but not all of them [51].…”

Section: Pva Degradation Pathway and Mechanismmentioning

confidence: 99%

Improved Ozonation Efficiency for Polymerization Mother Liquid from Polyvinyl Chloride Production Using Tandem Reactors

et al. 2019

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Polymerization mother liquid (PML) is one of the main sources of wastewater in the chlor-alkali industry. The effective degradation of the PML produced in PVC polymerization using three or five ozone reactors in tandem was designed with a focus on improving the ozonation efficiency. The ozonation efficiency of the tandem reactors for the degradation of PML, along with the effect of ozone concentration, the number of reactors utilized in series, and the reaction time on the chemical oxygen demand (COD) removal were investigated in detail. The results showed that the COD removal increased as the ozone concentration was increased from 10.6 to 60 mg·L−1, achieving 66.4% COD removal at ozone concentration of 80.6 mg·L−1. However, when the ozone concentration was increased from 60 mg·L−1 to 80 mg·L−1, the COD removal only increased very little. The COD decreased with increasing ozone concentration. During the initial degradation period, the degradation rate was the highest at both low and high ozone concentrations. The degradation rate decreased with reaction time. The rate at a low ozone concentration decreased more significantly than at high ozone concentration. Although high ozone concentration is desirable for COD removal and degradation rate, the utilization efficiency of ozone decreased with increasing ozone concentration. The ozone utilization efficiency of the five-reactor device was three times higher than that of three tandem reactors, demonstrating that ozonation utilization efficiency can be improved by increasing the number of tandem reactors. Ozonation in tandem reactors is a promising approach for PML treatment.

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“…Ozone (O 3 ) is a very strong oxidant and has attracted great interest for degrading organic pollutants, such as dyes (Wu et al, 2008a;Cuiping et al, 2009;Srinivasan et al, 2009) and other organic compounds (Perkowski et al, 1996;Yan et al, 2016), in wastewater, and it has been used in pilot-scale wastewater pre-treatment (Lucasa et al, 2010;Somensi et al, 2010). However, the reaction efficiency for ozonation alone is low (Gong et al, 2008;Cuiping et al, 2009;Rao and Chu, 2009) because the reactivity of O 3 depends on the chemical structure and hydrophilicity or hydrophobicity of pollutants, and the pH of the wastewater (Chang et al, 2012).…”

Section: Introductionmentioning

confidence: 99%

Ozone Catalytic Oxidation of Gaseous Toluene over MnO2-Based Ozone Decomposition Catalysts Immobilized on a Nonwoven Fabric

Sekiguchi

Kurita

Sankoda

et al. 2017

Aerosol Air Qual. Res.

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Degradation of toluene gas by ozone catalytic oxidation (OZCO) by using a MnO 2 -based ozone decomposition catalyst (ODC) was investigated to clarify the reactive site of ODC material with O 3 . An optimum structure for the ODC to remove O 3 and toluene were proposed. For honeycomb ODC, toluene degradation by OZCO occurred only around the entrance of the honeycomb ODC, and we expected that a thinner ODC would increase the toluene degradation efficiency. A nonwoven fabric on which ODC was immobilized was developed to decompose O 3 and volatile organic compounds simultaneously. The toluene degradation ratio and the mineralization of toluene to CO 2 were determined to evaluate the performance of the fabric. Furthermore, the effects of relative humidity and O 3 concentration on the decomposition and mineralization ratios were also investigated with or without 254 nm UV irradiation (UV 254 ). The fabric decomposed and mineralized toluene to CO 2 , even at low O 3 concentrations. Although high humidity reduced the degradation ratio of toluene, UV 254 irradiation improved the recovery of the degradation ratio and increased the mineralization ratio.

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Oxidation of potassium n -butyl xanthate with ozone: Products and pathways

Cited by 40 publications

References 15 publications

Degradation of Thiol Collectors Using Ozone at a Low Dosage: Kinetics, Mineralization, Ozone Utilization, and Changes of Biodegradability and Water Quality Parameters

Degradation of Thiol Collectors Using Ozone at a Low Dosage: Kinetics, Mineralization, Ozone Utilization, and Changes of Biodegradability and Water Quality Parameters

Improved Ozonation Efficiency for Polymerization Mother Liquid from Polyvinyl Chloride Production Using Tandem Reactors

Ozone Catalytic Oxidation of Gaseous Toluene over MnO2-Based Ozone Decomposition Catalysts Immobilized on a Nonwoven Fabric

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