CHEMOSPHERE
·
2017
·
IF 4.208
Jie Ma,Haiyan Li,Liping Chi,Hongkun Chen,Changzhao Chen
Persulfate (peroxydisulfate, S 2 O 8 2− ) is the newest oxidant used for the in situ chemical oxidation (ISCO) remediation of soil and groundwater. The present study investigated impacts of solution pH, temperature, and persulfate concentration on the reaction rate constant ( k 1 ), activation energy ( E a ), and reaction order of the heat-activated persulfate process. Phenol was chosen as the model organic contaminant . As temperature increased from 30 °C to 70 °C, k 1 exhibited a significant increase from 0.003 h −1 ∼0.962 h −1 (pH 1.3–13.9) to 1.184 h −1 ∼9.91 h −1 (pH 1.3–13.9), which corroborated with the activation of persulfate using heat. As pH increased from 1.3 to 13.9, k 1 exhibited a 4.3-fold increase at 70 °C and a 320-fold increase at 30 °C, thereby suggesting that: 1) the phenol oxidation rate increased under alkaline conditions, and 2) the enhancement of reaction rate due to alkaline activation was more pronounced at a lower temperature. Increasing pH significantly reduced E a from 139.7 ± 1.3 kJ/mol at pH 1.3 to 52.0 ± 3.3 kJ/mol at pH 13.9. In contrast to changing pH, increasing persulfate concentration from 20 to 320 mM significantly increased k 1 but did not affect E a . Changes in E a suggest that persulfate oxidation of phenol experienced different reaction pathways or elementary reaction sequences as the pH changed from 1.3 to 13.9. In addition, the k 1 and E a data also suggest that a minimal pH threshold of ∼11 was required for the effective alkaline activation of persulfate.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Earth and Space Chemistry
·
2024
·
IF 2.9
Cici Fan,Weigang Wang,Bo Shi,Zheng Sun,Maofa Ge
The relative rate method was used to determine the rate constant of Cl atoms and 3-buten-1-ol at ambient temperature and pressure. The main products of the reaction were identified as HCOOH with a yield of (50.07 ± 2.65)%, HCHO with a yield of (18.24 ± 0.65)%, HOCH2CHO with a yield of (18.69 ± 0.68)%, ClCH2CHO with a yield of (7.64 ± 0.25)%, respectively. The rate constant was (3.04 ± 0.36) × 10–10 cm3 molecules–1 s–1. The calculated theoretical rate constant was 2.91 × 10–10 cm3 molecules–1 s–1, which was in agreement with the experimental results. Moreover, the theoretical calculation showed that the two Cl-addition pathways were the main reaction pathway, but the proportion of H-abstraction pathways reached 29%, and its importance cannot be ignored. Based on this, the possible reaction mechanisms were deduced. The atmospheric implications of the obtained title reaction were briefly discussed.
研究领域:
大气化学
·
物理化学
✓ 已验证
产品关联
DOI
高影响因子
CHINESE JOURNAL OF CHEMICAL PHYSICS
·
2021
·Vol. 34
·期 4
·406-412
·
IF 1.114
Wang Chen,Xiong Ming-chen,Zhao Xuan,Liu Kun-hui
The pharmaceutically active compound atenolol, a kind of β -blockers, may result in adverse effects both for human health and ecosystems if it is excreted to the surface water resources. To effectively remove atenolol in the environment, both direct and indirect photodegradation, driven by sunlight play an important role. Among indirect photodegradation, singlet oxygen ( 1 O 2 ), as a pivotal reactive species, is likely to determine the fates of atenolol. Nevertheless, the kinetic information on the reaction of atenolol with singlet oxygen has not been well investigated and the reaction rate constant is still ambiguous. Herein, the reaction rate constant of atenolol with singlet oxygen is investigated directly through observing the decay of the 1 O 2 phosphorescence at 1270 nm. It is determined that the reaction rate constant between atenolol and 1 O 2 is 7.0×10 5 (mol/L) −1 · s −1 in D 2 O, 8.0×10 6 (mol/L) −1 · s −1 in acetonitrile, and 8.4×10 5 (mol/L) −1 · s −1 in EtOH, respectively. Furthermore, the solvent effects on the title reaction were also investigated. It is revealed that the solvents with strong polarity and weak hydrogen donating ability are suitable to achieve high rate constant values. These kinetics information on the reaction of atenolol with singlet oxygen may provide fundamental knowledge to the indirect photodegradation of β -blockers.
研究领域:
环境科学
·
药理学
·
化学动力学
✓ 已验证
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2018
·Vol. 25
·期 24
·24241-24252
·
IF 2.8
Zhu Jianqiang,Tsona Narcisse T.,Du Lin
Chloroalkenes are among the important anthropogenic organic compounds emitted in the atmosphere as a result of their wide use in synthetic processes in industry. Despite their well-known adverse effects on human health and air quality, the chemistry of these chloroalkenes remains poorly explored. In this work, reactions of 4-chloro-1-butene (CBE), a representative example of chloroalkenes, with O 3 , OH, NO 3 , and Cl are investigated in a 100-L Teflon reaction chamber equipped with gas chromatography-flame ionization detector (GC-FID). The absolute rate method was used for the reaction with O 3 while the relative rate method was used for reactions with OH, NO 3 , and Cl. The following rate constants were obtained at room temperature (298 ± 2) K and atmospheric pressure: (3.96 ± 0.43) × 10 −18 , (2.63 ± 0.96) × 10 −11 , (4.48 ± 1.23) × 10 −15 , and (2.35 ± 0.90) × 10 −10 cm 3 molecule −1 s −1 , for reactions with O 3 , OH, NO 3 , and Cl, respectively. Atmospheric lifetimes of CBE calculated from rate constants of the different reactions obtained in this work showed that reaction with OH is the main loss process for CBE, while in coastal areas and in the marine boundary layer, the CBE loss by Cl reaction becomes important. Estimation of the value of the photochemical ozone creation potential (POCP) indicated that CBE has a large ozone formation potential. The present work underlines the need for further studies on the atmospheric chemistry of chlorinated VOCs.
研究领域:
大气化学
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环境科学
·
有机化学
✓ 已验证
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2022
·
IF 4.889
Yu Xie,Mingjian Feng,Min Zhang,Weiguo Hu,Juan Huang,Yujun Wang,Guangsheng Luo
Piperacillin, an important penicillin, is generally synthesized by N -acylation of ampicillin and 4-ethyl-2,3-dioxo-1-piperazinecarbonyl chloride (EDPC) at the oil–water interface. A membrane dispersion microreactor can be used to synthesize high-quality piperacillin. However, research on the kinetics model of this process is limited. In this study, a high-speed microscope camera system was used to observe the liquid–liquid micro-dispersion trends in a microreactor, and the specific interface area was calculated. Furthermore, a constant interface cell was used to determine the relationship between the specific interface area and the reaction rate constant. Based on the findings of this study, a reaction kinetics model of piperacillin synthesis in the microreactor was established, demonstrating that EDPC was consumed within 0.124 s in the microreactor and coil. Subsequently, the piperacillin solution with a higher outlet concentration entered the reactor where it was rapidly diluted and circulated back to the inlet of the microreactor.
研究领域:
制药工程
·
化学动力学
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2020
·Vol. 27
·期 25
·31289-31299
·
IF 3.056
Zhu Mengyu,Lu Jun,Hu Yadong,Liu Ying,Hu Shuheng,Zhu Chengzhu
The superoxide anion radical (O 2 •− ) is one of the most predominant reactive oxygen species (ROS), which is also involved in diverse chemical and biological processes. In this study, O 2 •− was generated by irradiating riboflavin in an O 2 -saturated solution using an ultraviolet lamp ( λ em = 365 nm) as the light source. The photochemical reduction of 1,4-benzoquinone ( p -BQ) by O 2 •− was explored by 355-nm laser flash photolysis (LFP) and 365-nm UV light steady irradiation. The results showed that the photodecomposition efficiency of p -BQ was influenced by the riboflavin concentration, p -BQ initial concentration, and pH values. The superoxide anion radical originating from riboflavin photolysis served as a reductant to react with p -BQ, forming reduced BQ radicals (BQ •− ) with a second-order rate constant of 1.1 × 10 9 L mol −1 s −1 . The main product of the photochemical reaction between p -BQ and O 2 •− was hydroquinone (H 2 Q). The present work suggests that the reaction with O 2 •− is a potential transformation pathway of 1, 4-benzoquinone in atmospheric aqueous environments.
研究领域:
环境科学
·
化学
·
生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2018
·
IF 3.141
Rui Zhang,Wusan Jiang,Zhiwu Liang,Xiao Luo,Qi Yang
The CO2 reaction rate in aqueous 2-methylpiperazine (2MPZ) solution was investigated in terms of the pseudo-first-order rate constant (k0) by using a stopped-flow apparatus with amine concentration ranges of 0.05–0.125 mol/L and the measuring temperature ranges of 293.15–313.15 K. The results show that the CO2 reaction rate in the 2MPZ solution increased as the temperature and the amine concentration increases. The results also demonstrate that the 2MPZ has a faster reaction rate in terms of k0 than 3-dimethylaminopropylamine, 3-diethylaminopropylamine, and monoethanolamine (MEA) but slower than that of PZ at the same amine concentration. The equilibrium solubility as an important absorption parameter for CO2 capture also were measured at 298.15, 313.15, and 333.15 K with CO2 partial pressures of 5–100 kPa, respectively, in 2 M 2MPZ solution. The results show that the CO2 equilibrium solubility of 2MPZ increased as the CO2 partial pressure increased but decreased as the temperature increased. The heat of CO2 absorption in 2 M 2MPZ solution was estimated by using the Gibbs–Helmholtz equation, and the value (−70.9 kJ/mol) is similar to that of PZ but lower than that of MEA. Besides the conclusions stated above, the results of the 13C NMR quantitative investigation suggest that 2MPZ can produce less carbamate and more bicarbonate than PZ at the same CO2 loading.
研究领域:
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2016
·
IF 5.31
Jingxin Yang,Ji Li,Wenyi Dong,Jun Ma,Tingting Li,Yi Yang,Jiayin Li,Jia Gu
This study proposed deethylatrazine (DEA) as the OH probe compound during ozonation and compared with the widely used p -chlorobenzoic acid ( p CBA) for the first time. Results showed the ozone decay was not affected by DEA, but largely accelerated by p CBA as compared to the control. The DEA degradation was exclusively attributed to OH formation from ozonation of the tested waters, while p CBA was partially degraded by OH formation from the p CBA-derived propagation reactions. In synthetic waters with different OH scavenging capacities, the ozone decay rates with DEA were almost consistent with the control. The ozone decay rates with p CBA remained consistent with the control only in the synthetic waters with high OH scavenging capacities. For the synthetic waters with low OH scavenging capacities, p CBA led to higher ozone decay rates and OH exposures, and thus gave overestimated R ct values. The two OH probe compounds were also investigated in four authentic waters with different OH scavenging capacities. DEA exhibited no detectable effect on the ozone decay in all four authentic waters as compared to the control. The enhancing effects of p CBA on the ozone decay and OH formation were observed in the tap and reservoir water, which led to an overestimation of R ct as compared to the presence of DEA. In the ground water and wastewater, similar values were observed in ozone decay rates and R ct for the presence of p CBA and DEA. Thus, the use of p CBA as the OH probe compound should be carefully examined or avoided to prevent its interrupts in determining the R ct during ozonation of waters with different OH scavenging capacities. DEA is a more appropriate OH probe compound during ozonation.
研究领域:
环境科学
·
水处理工程
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL TECHNOLOGY
·
2025
·
IF 2
Tao Zhao,Minghao Xu,Xuerui Yang,Jean-Marc Chovelon,Lei Zhou
High-valent metal species (HVMS) exhibited exceptional oxidative capabilities and selectivity in advanced oxidation processes (AOPs), making them promising oxidants for environmental remediation. However, their inherent instability has hindered kinetic assessments and limited further applications. This study developed a quantitative structure–activity relationship (QSAR) model for predicting the pseudo-first order rate constants (kobs) of high-valent copper species Cu(III) with typical emerging contaminants (ECs). The optimal model was logkobs = 0.002×PSA – 10.1465 × q(C-)X – 4.5896 × ELUMO – 2.0116. R2adj (0.822), Q2LOO (0.784), and Q2ext (0.951) shown the model’s robust and great predictive ability. Polar surface area (PSA), Hirshfeld charge on carbon atoms (q(C-)X), and the energy of the lowest unoccupied molecular orbital (ELUMO) synergistically controlled the reactivity of Cu(III). A larger PSA was conducive to the diffusion of ECs in aquatic environments. Additionally, Density functional theory (DFT) calculations revealed that a smaller q(C-)X could increase the nucleophilic sites of ECs, thereby enhancing the electrophilic reaction of Cu(III). And a lower ELUMO was beneficial for adjusting the energy gap (EGAP) to enhance the reactivity of ECs. This study filled the gap in the prediction of kobs for Cu(III) and provided a reliable reference for the selective treatment of different ECs by HVMS.
研究领域:
环境科学
·
计算化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2017
·
IF 6.216
Zhiwen Cheng,Bowen Yang,Qincheng Chen,Zhemin Shen,Tao Yuan
In order to have a better prediction for the degradation reaction rate constant of organic compounds in Fenton process at different temperatures. A partial least squares (PLS) model was established based on 116 lg k values for 24 organic compounds and quantum chemical parameters, some basic information of molecules as well as the temperature of reaction system. The optimal model was demonstrated as stable, robust and had good predictive ability, with the associate statistical indices of adjusted squared correlation coefficient was 0.722, internal validation was 0.652, external validation was 0.512, cumulative cross-validation coefficient was 0.635, the criterions indicated the developed model could be used to estimate the reaction rate of organic compounds in Fenton process at different temperature. The model contains three components, the most significant descriptors explaining the reaction rate are T and 1/ T for component 1, the maximum charge in a carbon atom and minimum charge for nucleophilic attack for component 2, the charge in a hydrogen atom, maximum charge for hydroxyl radical attack and minimum value of bond order for component 3. The applicability domain (APD) of the proposed model was calculated by the Euclidean distances. The results of APD showed that the predictions by the derived PLS model were reliable. The proposed model not only offer a method to predict the reaction rates, but also give some insights of the mechanism for the degradation of organic compounds in Fenton process at different temperatures.
研究领域:
环境科学
·
化学
✓ 已验证
DOI
高影响因子
BULLETIN OF THE KOREAN CHEMICAL SOCIETY
·
2021
·Vol. 42
·期 10
·1336-1344
·
IF 0.969
Qilin Xu,Ji Ming Liu,Hongmiao Yao,Jinyang Zhao,Zhikuo Wang,Junli Liu,Jiadi Zhou,Zhiqun Yu,Weike Su
In this paper, the kinetics of acylation reaction of o -phenylenediamine/ p -phenylenediamine and benzoic anhydride were determined in microreactors, respectively. A kinetic model was established, all kinetic parameters including reaction orders, reaction rate constants, pre-exponential factors, and activation energies were acquired. Validation experiments showed experimental data fit well with calculated data at different reactant concentrations and residence times. The comparisons of the reaction rate constants and activation energies were summarized to show the difference of chemical reactivities of phenylenediamines. According to the calculation of the kinetic model, the optimized reaction conditions were listed to meet the monoacylation selectivity equal to 97.0%.
研究领域:
有机化学
·
化学工程
✓ 已验证
DOI
高影响因子
ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
·
2018
·
IF 3.974
Ting Tang,Guining Lu,Rui Wang,Zhiyuan Qiu,Kaibo Huang,Wenjie Lian,Xueqin Tao,Zhi Dang,Hua Yin
Advanced oxidation processes (AOPs), such as hydroxyl radical (•OH) and sulfate radical (•SO 4 - ) mediated oxidation, are proved to be effective methods to remove the organophosphorus esters (OPEs) in wastewater effluents. However, few studies have reported about the bimolecular reaction rate constants between free radicals (•OH and •SO 4 - ) and OPEs. This issue was solved by selecting three OPEs as model compounds, the oxidation of these OPEs in UV/H 2 O 2 and UV/K 2 S 2 O 8 process were studied. Tris(2-chloroethyl) phosphate (TCEP), tris(1-chloro-2-propyl) phosphate (TCPP), and tris(2,3-dichloropropyl) phosphate (TDCPP) can hardly be oxidized through direct irradiation methods using UV lamp, with the oxidation rate less than 30% after 7 h′ irradiation. However, TCEP, TCPP, and TDCPP undergo degradation via UV/H 2 O 2 and UV/K 2 S 2 O 8 processes easily, the oxidation rates increased with increasing H 2 O 2 and K 2 S 2 O 8 dosage. The oxidation rates of three OPEs have been studied using competition experiments in the UV/H 2 O 2 and UV/K 2 S 2 O 8 processes. The bimolecular reaction rate constants of TCEP, TCPP and TDCPP with •OH were 2.50 × 10 10 , 3.95 × 10 10 and 2.94 × 10 10 respectively; while •SO 4 - were 3.00 × 10 7 , 1.82 × 10 7 and 2.06 × 10 7 respectively. Results showed that the simplified kinetic model involves only steady state concentration of free radicals and the molecular reaction rate contents are available for calculating the oxidation rates of OPEs in ultrapure water.
研究领域:
环境科学
·
化学动力学
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）