Mechanism and kinetics study on the OH-initiated oxidation of organophosphorus pesticide trichlorfon in atmosphere

Yuan, Bao; Zhang, Chenxi; Yang, Wenbo; Hu, Jiayue; Sun, Xiaomin

doi:10.1016/j.scitotenv.2012.01.004

Cited by 20 publications

(12 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The SSTEP, which is a variable keyword in Polyrate 9.7 program (University of Minnesota, Minneapolis, MN, USA) that specifies the step size along the mass-scaled MEP, were confirmed as 0.05. This method has been comprehensively used in our previous papers on the rate constants of PCDD/F formation and degradation [ 28 , 29 , 30 , 31 , 46 , 47 , 48 ].…”

Section: Methodsmentioning

confidence: 99%

Theoretical Mechanistic and Kinetic Studies on Homogeneous Gas-Phase Formation of Polychlorinated Naphthalene from 2-Chlorophenol as Forerunner

Zhang

et al. 2015

IJMS

View full text Add to dashboard Cite

Polychlorinated naphthalenes (PCNs) are dioxins-like compounds and are formed along with polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in thermal and combustion procedures. Chlorophenols (CPs) are the most important forerunners of PCNs. A comprehensive comprehension of PCN formation procedure from CPs is a precondition for reducing the discharge of PCNs. Experiments on the formation of PCNs from CPs have been hindered by PCN toxicity and short of precise detection methods for active intermediate radicals. In this work, PCN formation mechanism in gas-phase condition from 2-chlorophenol (2-CP) as forerunner was studied by quantum chemistry calculations. Numbers of energetically advantaged formation routes were proposed. The rate constants of key elementary steps were calculated over 600–1200 K using canonical variational transition-state theory (CVT) with small curvature tunneling contribution (SCT) method. This study illustrates formation of PCNs with one chlorine atom loss from 2-CP is preferred over that without chlorine atom loss. In comparison with formation of PCDFs from 2-CP, PCN products are less chlorinated and have lower formation potential.

show abstract

Section: Methodsmentioning

confidence: 99%

Theoretical Mechanistic and Kinetic Studies on Homogeneous Gas-Phase Formation of Polychlorinated Naphthalene from 2-Chlorophenol as Forerunner

Zhang

et al. 2015

IJMS

View full text Add to dashboard Cite

show abstract

“…Obviously, there are two possible reaction ways for the reaction of DMP with OH • : one is OH addition to the aromatic ring, and the other is H‐abstraction on the aromatic ring. Several studies have suggested that OH‐addition pathways play a more dominant role than hydrogen abstraction pathways . Thus, only the reaction pathways of OH • addition are discussed in this paper, as depicted in Fig.…”

Section: Resultsmentioning

confidence: 99%

Dimethyl Phthalate Degradation by UV/H₂O₂: Combination of Experimental Methods and Quantum Chemical Calculation

Feng

Guo

et al. 2015

CLEAN Soil Air Water

View full text Add to dashboard Cite

Photochemical degradation of typical phthalate esters, as, e.g. dimethyl phthalate (DMP), in water by the UV/H2O2 process was investigated. The degradation rate of DMP was affected by several reaction factors, including initial DMP concentration, H2O2 concentration, UV light intensity, and coexisting cations and anions. The DMP degradation rate decreased with increasing initial DMP concentration. Carbonate ions significantly reduced the reaction rate by 70.2%, while the degradation rate was improved ten‐fold in the presence of ferric ions. The initial reaction mechanism and possible degradation products were investigated using density functional theory (DFT), including B3LYP and M062X hybrid functional. The addition of OH radicals (OH•) to the C4 position of the DMP ring is energetically favored for the initial reaction of DMP with OH•. Dimethyl 4‐hydroxyphthalate (DMP‐4OH) is one of the initial degradation intermediates. A possible reaction mechanism was also proposed based on GC/MS analysis and quantum chemical calculations. The formation of DMP‐4OH has been explained by quantum chemical calculations, which indicates the advantage and promising role of this method in the degradation mechanism analysis.

show abstract

“…15 Quantum chemical calculations are suitable for deciding a reaction path and determining the transition states and products of the reaction by providing the correct potential energy surface. 16,17 In the literature, there are some theoretical research studies on the degradation reaction of the OP with the •OH radical. In these studies, it has been showed that hydrogen atom abstraction from the α carbon atom is feasible reaction pathway.…”

Section: Accepted Manuscriptmentioning

confidence: 99%

“…In these studies, it has been showed that hydrogen atom abstraction from the α carbon atom is feasible reaction pathway. 5,[16][17][18] To the best of our knowledge, there are no study performed on the photo-oxidative degradation reactions of dimethyl dimethyl phosphoramidate (DDMP), diethyl phosphoramidate (DEP) and isoprophyl phosphorous (ISPC). Molecular structure of DDMP, DEP and ISPC are shown in the Fig.…”

Section: Accepted Manuscriptmentioning

confidence: 99%

Photodegradation kinetics of organophosphorous with hydroxyl radicals: Experimental and theoretical study

Aydogdu

Hatipoğlu

Eren

et al. 2021

JSCS

View full text Add to dashboard Cite

The presence of organophosphorus compounds (OPs) in the environmental counterparts has been an important problem because of their toxicity. In this study, the photocatalytic degradation reactions of the three OPs with hydroxyl radical were investigated by both experimental and quantum chemical methods. Photocatalytic degradation kinetics of organophosphorus compounds were investigated under UV-A irradiation using TiO2 as the photocatalyst. The effects of the initial concentrations on the degradation rate have been examined. There was an observable loss of OPs in the presence of TiO2 photocatalyst under UV-A at 0.2 g TiO2 per 100 mL. The quantum chemical calculations have been carried out by the Density Functional Theory (DFT) at B3LYP/6-31g(d) level. Reaction pathways were modeled to find the most probable mechanism for OPs with the OH radical and to determine the primary intermediates. The rate constants of the eight reaction paths were calculated by the Transition State Theory. CPCM (Conductor-like Polarizable Continuum Model) was used as the solvation model with the intention of understanding the water effect. Theoretical results were in agreement with experimental ones.

show abstract

Mechanism and kinetics study on the OH-initiated oxidation of organophosphorus pesticide trichlorfon in atmosphere

Cited by 20 publications

References 23 publications

Theoretical Mechanistic and Kinetic Studies on Homogeneous Gas-Phase Formation of Polychlorinated Naphthalene from 2-Chlorophenol as Forerunner

Theoretical Mechanistic and Kinetic Studies on Homogeneous Gas-Phase Formation of Polychlorinated Naphthalene from 2-Chlorophenol as Forerunner

Dimethyl Phthalate Degradation by UV/H₂O₂: Combination of Experimental Methods and Quantum Chemical Calculation

Photodegradation kinetics of organophosphorous with hydroxyl radicals: Experimental and theoretical study

Contact Info

Product

Resources

About

Mechanism and kinetics study on the OH-initiated oxidation of organophosphorus pesticide trichlorfon in atmosphere

Cited by 20 publications

References 23 publications

Theoretical Mechanistic and Kinetic Studies on Homogeneous Gas-Phase Formation of Polychlorinated Naphthalene from 2-Chlorophenol as Forerunner

Theoretical Mechanistic and Kinetic Studies on Homogeneous Gas-Phase Formation of Polychlorinated Naphthalene from 2-Chlorophenol as Forerunner

Dimethyl Phthalate Degradation by UV/H2O2: Combination of Experimental Methods and Quantum Chemical Calculation

Photodegradation kinetics of organophosphorous with hydroxyl radicals: Experimental and theoretical study

Contact Info

Product

Resources

About

Dimethyl Phthalate Degradation by UV/H₂O₂: Combination of Experimental Methods and Quantum Chemical Calculation