COMBUSTION AND FLAME
·
2025
·
IF 6.2
Zhongkai Liu,Mengqi Wu,Zhaohan Chu,Xiaoqing Wu,Jiabin Huang,Jiuzhong Yang,Bin Yang,Feng Zhang
In this work, we conducted a combined experimental and theoretical investigation into the reactivity of naphthylmethyl radical (1-A2CH 2 , C 11 H 9 ) with allene (aC 3 H 4 ) and propyne (pC 3 H 4 ). Co-pyrolysis experiments of 1-(chloromethyl)naphthalene (1-A2CH 2 Cl) with aC 3 H 4 or pC 3 H 4 were studied using a flash pyrolysis microreactor coupled with synchrotron vacuum ultraviolet photoionization mass spectrometry. Significant signals at m/z = 39 (C 3 H 3 ), attributed to the rapid H-abstraction and/or pyrolysis of C 3 H 4 molecules, were detected in both experiments, indicating concurrent radical-radical (1-A2CH 2 + C 3 H 3 ) and radical-molecule (1-A2CH 2 + aC 3 H 4 /pC 3 H 4 ) reactions. Theoretical calculations reveal that the radical-radical reaction is kinetically favored under experimental conditions compared to the radical-molecule reaction, dominantly forming two C 14 H 12 adducts, 1-(1,2-butadiene-4-yl)naphthalene (1-W1) and 1-(but‑yn-3-yl)naphthalene (1-W2), along with minor amounts of other C 14 H 12 isomers and C 14 H 11 + H products. The computed rate coefficients and branching ratios of various reaction channels expand the analysis to broader temperature and pressure ranges. The radical-radical products (1-W1 and 1-W2) dominate at atmospheric-to-high pressures (>1 atm) or relatively lower temperatures (<1500 K). At higher temperatures and low pressures, competition arises between radical-radical and radical-molecule pathways. Furthermore, the structures of bimolecular products differ significantly between the 1-A2CH 2 + aC 3 H 4 and 1-A2CH 2 + pC 3 H 4 reaction systems, with implications for the formation of larger polycyclic aromatic hydrocarbons.
研究领域:
化学动力学
·
理论计算
·
光谱学
✓ 已验证
产品关联
DOI
高影响因子
Plasma Processes and Polymers
·
2017
·Vol. 15
·期 4
·1700176
·
IF 2.846
Lei Wang,Jinxiu Wang,Junxin Lin,Songlin Zhang,Yongjun Liu
Degradation of metronidazole (MNZ) by radio frequency discharge in water was examined. Results showed that • OH, H • , and • O were produced. Decay of MNZ followed pseudo-first order kinetics, where the apparent rate constant was independent of its initial concentration in the range 0–0.5 mM, decreased in the range 0.5–1.0 mM, and leveled off in the range higher than 1.0 mM. pH had no effects on MNZ degradation. • OH scavengers enhanced the MNZ removal. Formic acid, nitrite ion, oxalic acid, nitrate ion, and acetic acid were determined as the primary intermediate byproducts. The eventual products were ammonia and inorganic carbon. Both • OH and H • participated in the MNZ degradation. H • played more efficient role than • OH in the early stage.
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2024
·
IF 12.2
Boqiang Li,Baiyang Chen,Zongsu Wei
UV/peroxydisulfate (UV/PDS) process is known to be highly efficient for degrading micropollutants from water by generating sulfate (SO 4 •− ) and hydroxyl radicals (HO • ). Reliable analyses of short-lived SO 4 •− and HO • are therefore critical for understanding reaction mechanisms and optimizing operating conditions. Currently, alcohols are commonly used as quenchers to distinguish radicals based on the assumption that they exclusively react with target radicals without other influences. However, this study for the first time reveals a series of unexpected effects that challenge this conventional wisdom because: 1) adding alcohols altered the decomposition rates of PDS by replacing the reactions between SO 4 •− and HO • with PDS by the reactions between secondary reactive species and PDS; and 2) SO 4 •− preferably reacted with alcohols to generate nonnegligible level of hydrogen peroxide (H 2 O 2 ) under oxygen-rich conditions, which subsequently led to indirect formation of HO • . Additionally, the formation of H 2 O 2 was substantially impacted by the types of alcohols, dosages, dissolved oxygen, and solution pH. Using probe tests as tools, we found that the actual SO 4 •− levels after dosing alcohols were only slightly different from assumed/expected levels, whereas the actually HO • levels were 43.7, 3364.9, and 12.5 times higher than assumed/expected conditions for samples dosed with methanol, iso-propanol, and tert-butanol, respectively. These unanticipated effects thus suggest that cautions are needed when using alcohols to qualitative and quantitative determine HO • and SO 4 •− in UV/PDS process.
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
JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY
·
2021
·Vol. 331
·期 1
·241-247
·
IF 1.371
Wang J. H.,Zhao X. Y.,Shi Y.,Wan Y.,Fu H. Y.,Zheng W. F.
The reaction mechanisms and rate constants of N, N-diethylhydroxylamine (DEHA) with · OH, CO 3 − · , e aq − and · H were studied. Results show that · OH radicals oxidize DEHA by hydrogen abstraction from DEHA’s hydroxyl group to form transient (C 2 H 5 ) 2 NO · , which has an absorption maximum at 395 nm. The transient intermediates for the reactions of DEHA with CO 3 − · and e aq − , as well as protonated DEHA with · H, show no absorption peak between 300 and 800 nm. The rate constants for the reactions of DEHA with · OH, CO 3 − · and e aq − , also protonated DEHA with · H, were measured.
研究领域:
放射化学
·
自由基化学
✓ 已验证
产品关联
DOI
高影响因子
Nano Energy
·
2023
·
IF 17.6
Yi Zhao,Yang Liu,Yuying Wang,Shulan Li,Yi Liu,Zhong Lin Wang,Peng Jiang
Solid-liquid interfaces are ubiquitous in nature and widely used in various applications such as catalysis, sensing, batteries , etc. Recently, we found the existence of electron transfer at the interface in solid-liquid contacting, and proposed a “two-step” theory for the formation of solid-liquid electric double layer (EDL). In this work, we found that hydroxyl radical (·OH) was generated when the droplet contact with the tube inner wall without external interference, and the concentration of·OH was increased with increasing pH, demonstrating that the·OH was generated from hydroxide ions (OH - ) by electron transfer during contact electrification. This can be further supported by the fact that capillaries made of materials with stronger electron-withdrawing ability could generate more·OH. Interestingly, superoxide anion radical (·O 2 - ) was not generated at the solid-liquid interface if no external energy is provided. However, if ultrasonic was applied,·O 2 - could be generated at the solid-liquid interface, because ultrasonication provides transition energy for the electron to transfer from the solid to O 2 at the interface. Based on the generation of reactive oxygen species (·OH and·O 2 - ), we demonstrated a proof-of-concept for degradation of tetracycline pollution. This work provides an excellent strategy to study the solid-liquid interface and also provides a new insight into the free radical generation at the interface in solid-liquid contacting.
研究领域:
化学
·
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
WATER RESEARCH
·
2018
·
IF 7.051
Tongcai Liu,Kai Yin,Chengbin Liu,Jinming Luo,John Crittenden,Weiqiu Zhang,Shenglian Luo,Qunying He,Yongxiu Deng,Hui Liu,Danyu Zhang
Oxcarbazepine (OXC) is ubiquitous in the aqueous environment. And due to its ecotoxicological effects and potential risks to human, an effective way to eliminate OXC from aqueous environment has aroused public concerns in recent years. Radical-based reactions have been shown to be an efficient way for OXC destruction, but the reactions of OXC with reactive oxygen species (ROS) and carbonate radical (CO 3 •− ) are still unclear. In this study, we focused the degradation of OXC and ROS, CO 3 •− generation mechanism, and their roles in OXC degradation via UV and UV/H 2 O 2 . The triplet state of oxcarbazepine ( 3 OXC ∗ ) was found to play an important role in OXC degradation via UV. And hydroxyl radicals ( • OH) and singlet oxygen ( 1 O 2 ) were found to be the dominant ROS in OXC degradation. Superoxide radical (O 2 •− ) did not react with OXC directly, but it may react with intermediate byproducts. Generation of CO 3 •− played a positive role on OXC degradation for both UV and UV/H 2 O 2 . In addition to • OH, 3 OXC* also contribute to CO 3 •− production. The second-order rate constants of OXC with • OH and CO 3 •− were 1.7 × 10 10 M −1 s −1 and 8.6 × 10 7 M −1 s −1 , respectively. Potential OXC degradation mechanisms by • OH were proposed and included hydroxylation, α-ketol rearrangement, and benzylic acid rearrangement. Compared with non-selective • OH, the reactions involving CO 3 •− are mainly electron transfer and hydrogen abstraction. And the acute toxicity of OXC was lower after UV/H 2 O 2 and UV/H 2 O 2 /HCO 3 − treatments, which was confirmed by luminescent bacterial assay ( Vibrio fischeri bacterium).
研究领域:
环境科学
·
毒理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2022
·
IF 24.319
Peng Zhou,Yangyang Yang,Wei Ren,Xiaojie Li,Yongli Zhang,Bo Lai,Shaobin Wang,Xiaoguang Duan
In this work, crystalline boron is applied as a green co-catalyst to accelerate the redox processes in the Fe(III)/PMS(peroxymonosulfate) system. The semi-metallic B-B bonds in the icosahedra B 12 unit of boron will donate electrons to reduce Fe(III) to initiate Fenton-like PMS activation to generate hydroxyl radical (•OH), sulfate radical (SO 4 •− ) and high-valence Fe(IV). Meanwhile, surface boron can directly cleave the peroxide O-O bonds of PMS molecules to produce •OH. The contributions of radical and Fe(IV) can be regulated by Fe(III) dosage, and parallel radical and nonradical oxidation will enable non-selective degradation of diverse organic contaminants with high PMS utilization efficiency. Moreover, Fe(III) accelerates the self-clean of boron surface and secures continuous exposure of active sites. Spontaneously, boron experiences stepwise oxidation and hydrolysis into soluble products without generating toxins. The novel Boron/Fe(III)/PMS system overcomes the rate-limiting step in Fenton chemistry and realizes exceptional efficiency and stability in long-term operations.
研究领域:
环境科学
·
催化化学
✓ 已验证
DOI
高影响因子
WATER RESEARCH
·
2019
·
IF 7.913
Xinran Zhang,Pengfei Ren,Weiguang Li,Yu Lei,Xin Yang,Ernest R. Blatchley
The presence of ammonium (NH 4 + ) in drinking water treatment results in inhibition of disinfection efficiency and formation of nitrogenous disinfection by-products. Our previous study found monochloramine (NH 2 Cl) photolysis under 254 nm UV irradiation can be effective for removal of NH 4 + ; however, the mechanisms of NH 4 + degradation in this process were unknown. The kinetics and fundamental radical chemistry responsible for NH 4 + removal in the UV/NH 2 Cl process were investigated in this study. The results showed that the pseudo first-order rate constant for NH 4 + degradation in the UV/NH 2 Cl process ranged between 3.6 × 10 −4 to 1.8 × 10 −3 s −1 . Solution pH affected radical conversion and a higher NH 4 + degradation efficiency was achieved under acidic conditions. The effects of chloride were limited; however, the presence of either bicarbonate or natural organic matter scavenged radicals and inhibited NH 4 + removal. NH 2 Cl photolysis generated an aminyl radical (NH 2 • ) and a chlorine radical (Cl • ) that further transformed to a chlorine dimer (Cl 2 •- ) and a hydroxyl radical (HO • ). The second-order rate constants for Cl • and Cl 2 •- reacting with NH 4 + were estimated as 2.59 × 10 8 M −1 s −1 and 3.45 × 10 5 M −1 s −1 at pH 3.9, respectively. Cl • , Cl 2 •- , and HO • contributed 95.2%, 3.5%, and 1.3% to NH 4 + removal, respectively, at the condition of 3 mM NH 2 Cl and pH 7.5. Major products included nitrite and nitrate, possibly accompanied by nitrogen-containing gases. This investigation provides insight into the photochemistry of NH 4 + degradation in the UV/NH 2 Cl process and offers an alternative method for drinking water production.
研究领域:
环境科学
·
饮用水处理
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of the Taiwan Institute of Chemical Engineers
·
2017
·
IF 4.217
Jing Zhang,Jing Guo,Yao Wu,Yeqing Lan,Ying Li
A series batch experiments were performed to explore the catalytic role of zero-valent metals, including Fe(0), Co(0), Al(0) and Cu(0), in ozonation degradation of aniline in aqueous solution. It was found that Cu(0) exhibited the best catalytic activity of ozonation. Approximately 98% of the initial aniline (10 mg/L) was destructed by ozone assisted with Cu(0) within 24 min. The dosage of Cu(0) and solution pH were two critical factors affecting aniline degradation. The increase of Cu(0) dosage promoted aniline degradation. And aniline could be effectively removed in an initial pH range of 4–10, whereas a lower or higher solution pH was not favorable for the degradation of aniline. Free radicals were investigated by electron paramagnetic resonance technique, which confirmed that ·OH was the primary active oxidant responsible for the degradation of aniline. The further mechanism investigation revealed that the generation of ·OH is ascribed to Fenton-like reaction between Cu(I) and H 2 O 2 , both of which are in situ yielded through a series subsequent of reactions starting with oxidation–reduction reaction between ozone and Cu(0). Based on the results obtained in this study, it can be inferred that ozone activated with Cu(0) is a promising approach to degrade organic pollutants .
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2018
·
IF 6.735
Shizong Wang,Jianlong Wang
The effect of common inorganic anions (chloride, bicarbonate, carbonate, nitrate, sulfate and phosphate) on the radiation-induced degradation of sulfamethoxazole (SMX) was investigated. In the absence of anions, the removal efficiency of SMX reached 99.6% at dose of 1 kGy. However, the presence of inorganic anions had obvious influence on SMX degradation, which was dependent on their initial concentrations. Nitrate ions had inhibitive effect, which increased with increase of its initial concentration. Chloride ions showed no obvious inhibition at low concentration, while they had significant inhibition at higher concentration. For bicarbonate, carbonate and phosphate ions, they presented inhibition at low concentration, while they had enhancing effect at higher concentration. The promotion of SMX removal efficiency was observed when the initial concentration of bicarbonate, carbonate and phosphate was 50, 20 and 50 mM, respectively. Quenching experiments proved that hydroxyl radicals made a major contribution to SMX degradation in the absence of anions. However, in the presence of 50 mM of carbonate or phosphate ions, carbonate and phosphate radicals played a key role in SMX degradation. In addition, carbonate and phosphate radicals preferentially attacked the amino group and resulted in the formation of different intermediate products compared to hydroxyl radicals. The results suggested that the effect of inorganic anions on the radiation-induced degradation of sulfonamides antibiotics should be considered when radiation technology is used for the treatment of industrial wastewater.
研究领域:
环境科学
·
药学
·
放射化学
✓ 已验证
产品关联
DOI
高影响因子
ULTRASONICS SONOCHEMISTRY
·
2021
·
IF 7.491
Zhen-Dan Xue,Qing-An Zhang,Hong-Rong Zheng
In order to explore the effects of ultrasound on the formation of acetaldehyde and its mechanism in model wine solutions, ultrasound conditions and free radicals were investigated by response surface methodology and electron paramagnetic resonance spectroscopy (EPR), respectively. The results indicate that ultrasound does induce the production of acetaldehyde with the maximum amount under the conditions of ultrasound power density 0.2 W/cm 2 , 48 min and 32 °C. The hydroxyl radicals and the 1-hydroxyethyl free radicals are the main initiator and precursor for acetaldehyde, respectively. Furthermore, the stronger the 1-hydroxyethyl free radicals captured by EPR, the lower the formation of acetaldehyde. In addition, the content of Fe 2+ and ethanol also exerted a certain influence on the acetaldehyde formation. In conclusion, ultrasound does promote the production of acetaldehyde in the model wine solutions, which is beneficial for well understanding the mechanism of ultrasound in modifying the wine color and accelerating ageing.
研究领域:
食品科学
·
化学
·
酿酒学
✓ 已验证
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Yujiao Wen,Lide Liu,Dong He,Jinmeng Wu,Wenzhi Yang,Shikai Li,Shiya Wang,Lezhu Su,Zhi Zhou,Zhonghua Zhou,Nan Zhou
To explore highly effective and nonmetallic advanced oxidation process system to alleviate the persistent herbicides contamination in agricultural soils is of great importance. In this study, a significantly graphitized biochar with abundant C = O structure is prepared as non-metallic catalyst (WCGBC800). Different from other traditional amorphous pristine biochar, WCGBC800 can accelerate the electron transfer in the system and then effectively activate peroxymonosulfate (PMS) to produce free ( OH, O 2 – , SO 4 − , etc.) and non-free radicals ( 1 O 2 , electron transfer, etc.). Consequently, WCGBC800 can degrade 100 % the persistent organic herbicide quinclorac (QNC, with a content of 50 mg·kg −1 ) in soil within 20 min after PMS addition. The T.E.S.T-QSAR software simulation evidence that the toxicity of degradation intermediates is much lower than QNC. The stress of QNC on rice seedlings was directly described through rice cultivation experiment. The stress of rice seedlings was relieved after WCGBC800 + PMS treatment. The growth experiment of rice seedlings also shows that with an original QNC concentration of 7 mg·kg −1 in soil, the root length, root surface area, leaf length, leaf area, and leaves perimeter of rice increase of 255.30 %, 148.38 %, 207.64 %, 204.19 %, and 63.69 % respectively after detoxification by WCGBC800 + PMS system. This functional material and the WCGBC800 + PMS system provide new solutions for solving the problem of herbicide residues in soil with promising safety.
研究领域:
环境科学
·
农业科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）